This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
[perl #22395] regexp /(.*)[bc]/ 10000 times slower in 5.8.0 vs 5.6.1
[perl5.git] / regcomp.c
index e64702a..f8052a1 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -113,14 +113,20 @@ typedef struct RExC_state_t {
     I32                sawback;                /* Did we see \1, ...? */
     U32                seen;
     I32                size;                   /* Code size. */
-    I32                npar;                   /* () count. */
+    I32                npar;                   /* Capture buffer count, (OPEN). */
+    I32                cpar;                   /* Capture buffer count, (CLOSE). */
+    I32                nestroot;               /* root parens we are in - used by accept */
     I32                extralen;
     I32                seen_zerolen;
     I32                seen_evals;
-    regnode    **parens;               /* offsets of each paren */
+    regnode    **open_parens;          /* pointers to open parens */
+    regnode    **close_parens;         /* pointers to close parens */
+    regnode    *opend;                 /* END node in program */
     I32                utf8;
     HV         *charnames;             /* cache of named sequences */
     HV         *paren_names;           /* Paren names */
+    regnode    **recurse;              /* Recurse regops */
+    I32                recurse_count;          /* Number of recurse regops */
 #if ADD_TO_REGEXEC
     char       *starttry;              /* -Dr: where regtry was called. */
 #define RExC_starttry  (pRExC_state->starttry)
@@ -148,13 +154,19 @@ typedef struct RExC_state_t {
 #define RExC_seen      (pRExC_state->seen)
 #define RExC_size      (pRExC_state->size)
 #define RExC_npar      (pRExC_state->npar)
+#define RExC_cpar      (pRExC_state->cpar)
+#define RExC_nestroot   (pRExC_state->nestroot)
 #define RExC_extralen  (pRExC_state->extralen)
 #define RExC_seen_zerolen      (pRExC_state->seen_zerolen)
 #define RExC_seen_evals        (pRExC_state->seen_evals)
 #define RExC_utf8      (pRExC_state->utf8)
 #define RExC_charnames  (pRExC_state->charnames)
-#define RExC_parens    (pRExC_state->parens)
+#define RExC_open_parens       (pRExC_state->open_parens)
+#define RExC_close_parens      (pRExC_state->close_parens)
+#define RExC_opend     (pRExC_state->opend)
 #define RExC_paren_names       (pRExC_state->paren_names)
+#define RExC_recurse   (pRExC_state->recurse)
+#define RExC_recurse_count     (pRExC_state->recurse_count)
 
 #define        ISMULT1(c)      ((c) == '*' || (c) == '+' || (c) == '?')
 #define        ISMULT2(s)      ((*s) == '*' || (*s) == '+' || (*s) == '?' || \
@@ -182,6 +194,14 @@ typedef struct RExC_state_t {
 #endif
 
 
+
+#define PBYTE(u8str,paren) ((U8*)(u8str))[(paren) >> 3]
+#define PBITVAL(paren) (1 << ((paren) & 7))
+#define PAREN_TEST(u8str,paren) ( PBYTE(u8str,paren) & PBITVAL(paren))
+#define PAREN_SET(u8str,paren) PBYTE(u8str,paren) |= PBITVAL(paren)
+#define PAREN_UNSET(u8str,paren) PBYTE(u8str,paren) &= (~PBITVAL(paren))
+
+
 /* About scan_data_t.
 
   During optimisation we recurse through the regexp program performing
@@ -319,7 +339,7 @@ static const scan_data_t zero_scan_data =
 #define SCF_WHILEM_VISITED_POS 0x2000
 
 #define SCF_TRIE_RESTUDY        0x4000 /* Do restudy? */
-
+#define SCF_SEEN_ACCEPT         0x8000 
 
 #define UTF (RExC_utf8 != 0)
 #define LOC ((RExC_flags & PMf_LOCALE) != 0)
@@ -483,7 +503,7 @@ static const scan_data_t zero_scan_data =
 #define Set_Node_Offset_To_R(node,byte) STMT_START {                   \
     if (! SIZE_ONLY) {                                                 \
        MJD_OFFSET_DEBUG(("** (%d) offset of node %d is %d.\n",         \
-                   __LINE__, (node), (int)(byte)));                    \
+                   __LINE__, (int)(node), (int)(byte)));               \
        if((node) < 0) {                                                \
            Perl_croak(aTHX_ "value of node is %d in Offset macro", (int)(node)); \
        } else {                                                        \
@@ -531,7 +551,7 @@ static const scan_data_t zero_scan_data =
 #define DEBUG_STUDYDATA(data,depth)                                  \
 DEBUG_OPTIMISE_MORE_r(if(data){                                           \
     PerlIO_printf(Perl_debug_log,                                    \
-        "%*s"/* Len:%"IVdf"/%"IVdf" */" Pos:%"IVdf"/%"IVdf           \
+        "%*s"/* Len:%"IVdf"/%"IVdf" */"Pos:%"IVdf"/%"IVdf           \
         " Flags: %"IVdf" Whilem_c: %"IVdf" Lcp: %"IVdf" ",           \
         (int)(depth)*2, "",                                          \
         (IV)((data)->pos_min),                                       \
@@ -668,6 +688,8 @@ STATIC void
 S_cl_and(struct regnode_charclass_class *cl,
        const struct regnode_charclass_class *and_with)
 {
+
+    assert(and_with->type == ANYOF);
     if (!(and_with->flags & ANYOF_CLASS)
        && !(cl->flags & ANYOF_CLASS)
        && (and_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
@@ -820,7 +842,7 @@ S_dump_trie(pTHX_ const struct _reg_trie_data *trie,U32 depth)
         PerlIO_printf( Perl_debug_log, "%.*s", colwidth, "--------");
     PerlIO_printf( Perl_debug_log, "\n");
 
-    for( state = 1 ; state < trie->laststate ; state++ ) {
+    for( state = 1 ; state < trie->statecount ; state++ ) {
        const U32 base = trie->states[ state ].trans.base;
 
         PerlIO_printf( Perl_debug_log, "%*s#%4"UVXf"|", (int)depth * 2 + 2,"", (UV)state);
@@ -903,10 +925,13 @@ S_dump_trie_interim_list(pTHX_ const struct _reg_trie_data *trie, U32 next_alloc
                            (SvUTF8(*tmp) ? PERL_PV_ESCAPE_UNI : 0) |
                            PERL_PV_ESCAPE_FIRSTCHAR 
                     ) ,
-                TRIE_LIST_ITEM(state,charid).forid,
-                (UV)TRIE_LIST_ITEM(state,charid).newstate
-            );
-        }
+                    TRIE_LIST_ITEM(state,charid).forid,
+                    (UV)TRIE_LIST_ITEM(state,charid).newstate
+                );
+                if (!(charid % 10)) 
+                    PerlIO_printf(Perl_debug_log, "\n%*s| ",
+                        (int)((depth * 2) + 14), "");
+            }
         }
         PerlIO_printf( Perl_debug_log, "\n");
     }
@@ -1098,10 +1123,11 @@ is the recommended Unicode-aware way of saying
     *(d++) = uv;
 */
 
-#define TRIE_STORE_REVCHAR                                                    \
+#define TRIE_STORE_REVCHAR                                                 \
     STMT_START {                                                           \
-       SV *tmp = Perl_newSVpvf_nocontext( "%c", (int)uvc );               \
+       SV *tmp = newSVpvs("");                                            \
        if (UTF) SvUTF8_on(tmp);                                           \
+       Perl_sv_catpvf( aTHX_ tmp, "%c", (int)uvc );                       \
        av_push( TRIE_REVCHARMAP(trie), tmp );                             \
     } STMT_END
 
@@ -1133,9 +1159,8 @@ is the recommended Unicode-aware way of saying
 
 #define TRIE_LIST_PUSH(state,fid,ns) STMT_START {               \
     if ( TRIE_LIST_CUR( state ) >=TRIE_LIST_LEN( state ) ) {    \
-       TRIE_LIST_LEN( state ) *= 2;                            \
-       Renew( trie->states[ state ].trans.list,                \
-              TRIE_LIST_LEN( state ), reg_trie_trans_le );     \
+       U32 ging = TRIE_LIST_LEN( state ) *= 2;                 \
+       Renew( trie->states[ state ].trans.list, ging, reg_trie_trans_le ); \
     }                                                           \
     TRIE_LIST_ITEM( state, TRIE_LIST_CUR( state ) ).forid = fid;     \
     TRIE_LIST_ITEM( state, TRIE_LIST_CUR( state ) ).newstate = ns;   \
@@ -1171,7 +1196,7 @@ is the recommended Unicode-aware way of saying
     if ( noper_next < tail ) {                                  \
         if (!trie->jump)                                        \
             Newxz( trie->jump, word_count + 1, U16);            \
-        trie->jump[curword] = (U16)(tail - noper_next);         \
+        trie->jump[curword] = (U16)(noper_next - convert);      \
         if (!jumper)                                            \
             jumper = noper_next;                                \
         if (!nextbranch)                                        \
@@ -1222,6 +1247,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
     U32 next_alloc = 0;
     regnode *jumper = NULL;
     regnode *nextbranch = NULL;
+    regnode *convert = NULL;
     /* we just use folder as a flag in utf8 */
     const U8 * const folder = ( flags == EXACTF
                        ? PL_fold
@@ -1270,6 +1296,16 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
                   REG_NODE_NUM(last), REG_NODE_NUM(tail),
                   (int)depth);
     });
+   
+   /* Find the node we are going to overwrite */
+    if ( first == startbranch && OP( last ) != BRANCH ) {
+        /* whole branch chain */
+        convert = first;
+    } else {
+        /* branch sub-chain */
+        convert = NEXTOPER( first );
+    }
+        
     /*  -- First loop and Setup --
 
        We first traverse the branches and scan each word to determine if it
@@ -1394,6 +1430,10 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
 
         STRLEN transcount = 1;
 
+        DEBUG_TRIE_COMPILE_MORE_r( PerlIO_printf( Perl_debug_log, 
+            "%*sCompiling trie using list compiler\n",
+            (int)depth * 2 + 2, ""));
+
         Newxz( trie->states, TRIE_CHARCOUNT(trie) + 2, reg_trie_state );
         TRIE_LIST_NEW(1);
         next_alloc = 2;
@@ -1456,13 +1496,14 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
 
         } /* end second pass */
 
-        trie->laststate = next_alloc;
+        /* next alloc is the NEXT state to be allocated */
+        trie->statecount = next_alloc; 
         Renew( trie->states, next_alloc, reg_trie_state );
 
         /* and now dump it out before we compress it */
         DEBUG_TRIE_COMPILE_MORE_r(
             dump_trie_interim_list(trie,next_alloc,depth+1)
-                    );
+        );
 
         Newxz( trie->trans, transcount ,reg_trie_trans );
         {
@@ -1571,7 +1612,9 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
            use TRIE_NODENUM() to convert.
 
         */
-
+        DEBUG_TRIE_COMPILE_MORE_r( PerlIO_printf( Perl_debug_log, 
+            "%*sCompiling trie using table compiler\n",
+            (int)depth * 2 + 2, ""));
 
         Newxz( trie->trans, ( TRIE_CHARCOUNT(trie) + 1 ) * trie->uniquecharcount + 1,
               reg_trie_trans );
@@ -1695,7 +1738,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
         const U32 laststate = TRIE_NODENUM( next_alloc );
        U32 state, charid;
         U32 pos = 0, zp=0;
-        trie->laststate = laststate;
+        trie->statecount = laststate;
 
         for ( state = 1 ; state < laststate ; state++ ) {
             U8 flag = 0;
@@ -1732,7 +1775,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
             }
         }
         trie->lasttrans = pos + 1;
-        Renew( trie->states, laststate + 1, reg_trie_state);
+        Renew( trie->states, laststate, reg_trie_state);
         DEBUG_TRIE_COMPILE_MORE_r(
                 PerlIO_printf( Perl_debug_log,
                    "%*sAlloc: %d Orig: %"IVdf" elements, Final:%"IVdf". Savings of %%%5.2f\n",
@@ -1745,6 +1788,12 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
 
         } /* end table compress */
     }
+    DEBUG_TRIE_COMPILE_MORE_r(
+            PerlIO_printf(Perl_debug_log, "%*sStatecount:%"UVxf" Lasttrans:%"UVxf"\n",
+                (int)depth * 2 + 2, "",
+                (UV)trie->statecount,
+                (UV)trie->lasttrans)
+    );
     /* resize the trans array to remove unused space */
     Renew( trie->trans, trie->lasttrans, reg_trie_trans);
 
@@ -1754,7 +1803,6 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
     );
 
     {   /* Modify the program and insert the new TRIE node*/ 
-        regnode *convert;
         U8 nodetype =(U8)(flags & 0xFF);
         char *str=NULL;
         
@@ -1772,23 +1820,22 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
            the whole branch sequence, including the first.
          */
         /* Find the node we are going to overwrite */
-        if ( first == startbranch && OP( last ) != BRANCH ) {
-            /* whole branch chain */
-            convert = first;
-            DEBUG_r({
-                const  regnode *nop = NEXTOPER( convert );
-                mjd_offset= Node_Offset((nop));
-                mjd_nodelen= Node_Length((nop));
-            });
-        } else {
+        if ( first != startbranch || OP( last ) == BRANCH ) {
             /* branch sub-chain */
-            convert = NEXTOPER( first );
             NEXT_OFF( first ) = (U16)(last - first);
             DEBUG_r({
                 mjd_offset= Node_Offset((convert));
                 mjd_nodelen= Node_Length((convert));
             });
+            /* whole branch chain */
+        } else {
+            DEBUG_r({
+                const  regnode *nop = NEXTOPER( convert );
+                mjd_offset= Node_Offset((nop));
+                mjd_nodelen= Node_Length((nop));
+            });
         }
+        
         DEBUG_OPTIMISE_r(
             PerlIO_printf(Perl_debug_log, "%*sMJD offset:%"UVuf" MJD length:%"UVuf"\n",
                 (int)depth * 2 + 2, "",
@@ -1800,12 +1847,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
         trie->startstate= 1;
         if ( trie->bitmap && !trie->widecharmap && !trie->jump  ) {
             U32 state;
-            DEBUG_OPTIMISE_r(
-                PerlIO_printf(Perl_debug_log, "%*sLaststate:%"UVuf"\n",
-                    (int)depth * 2 + 2, "",
-                    (UV)trie->laststate)
-           );
-            for ( state = 1 ; state < trie->laststate-1 ; state++ ) {
+            for ( state = 1 ; state < trie->statecount-1 ; state++ ) {
                 U32 ofs = 0;
                 I32 idx = -1;
                 U32 count = 0;
@@ -1906,7 +1948,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
               jump[0], which is otherwise unused by the jump logic. 
               We use this when dumping a trie and during optimisation. */
            if (trie->jump) 
-               trie->jump[0] = (U16)(tail - nextbranch);
+               trie->jump[0] = (U16)(nextbranch - convert);
             
             /* XXXX */
             if ( !trie->states[trie->startstate].wordnum && trie->bitmap && 
@@ -1982,7 +2024,7 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
     reg_trie_data *trie=(reg_trie_data *)RExC_rx->data->data[ARG(source)];
     U32 *q;
     const U32 ucharcount = trie->uniquecharcount;
-    const U32 numstates = trie->laststate;
+    const U32 numstates = trie->statecount;
     const U32 ubound = trie->lasttrans + ucharcount;
     U32 q_read = 0;
     U32 q_write = 0;
@@ -2002,7 +2044,7 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
     RExC_rx->data->data[ data_slot ] = (void*)aho;
     aho->trie=trie;
     aho->states=(reg_trie_state *)savepvn((const char*)trie->states,
-        (trie->laststate+1)*sizeof(reg_trie_state));
+        numstates * sizeof(reg_trie_state));
     Newxz( q, numstates, U32);
     Newxz( aho->fail, numstates, U32 );
     aho->refcount = 1;
@@ -2051,7 +2093,10 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
      */
     fail[ 0 ] = fail[ 1 ] = 0;
     DEBUG_TRIE_COMPILE_r({
-        PerlIO_printf(Perl_debug_log, "%*sStclass Failtable: 0", (int)(depth * 2), "");
+        PerlIO_printf(Perl_debug_log,
+                     "%*sStclass Failtable (%"UVuf" states): 0", 
+                     (int)(depth * 2), "", (UV)numstates
+        );
         for( q_read=1; q_read<numstates; q_read++ ) {
             PerlIO_printf(Perl_debug_log, ", %"UVuf, (UV)fail[q_read]);
         }
@@ -2074,14 +2119,14 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
 #endif
 
 #define DEBUG_PEEP(str,scan,depth) \
-    DEBUG_OPTIMISE_r({ \
+    DEBUG_OPTIMISE_r({if (scan){ \
        SV * const mysv=sv_newmortal(); \
        regnode *Next = regnext(scan); \
        regprop(RExC_rx, mysv, scan); \
-       PerlIO_printf(Perl_debug_log, "%*s" str ">%3d: %s [%d]\n", \
+       PerlIO_printf(Perl_debug_log, "%*s" str ">%3d: %s (%d)\n", \
        (int)depth*2, "", REG_NODE_NUM(scan), SvPV_nolen_const(mysv),\
        Next ? (REG_NODE_NUM(Next)) : 0 ); \
-   });
+   }});
 
 
 
@@ -2239,15 +2284,38 @@ S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, I32 *min, U32 flags
 /* Stops at toplevel WHILEM as well as at "last". At end *scanp is set
    to the position after last scanned or to NULL. */
 
-
+#define INIT_AND_WITHP \
+    assert(!and_withp); \
+    Newx(and_withp,1,struct regnode_charclass_class); \
+    SAVEFREEPV(and_withp)
+
+/* this is a chain of data about sub patterns we are processing that
+   need to be handled seperately/specially in study_chunk. Its so
+   we can simulate recursion without losing state.  */
+struct scan_frame;
+typedef struct scan_frame {
+    regnode *last;  /* last node to process in this frame */
+    regnode *next;  /* next node to process when last is reached */
+    struct scan_frame *prev; /*previous frame*/
+    I32 stop; /* what stopparen do we use */
+} scan_frame;
 
 STATIC I32
-S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, 
+S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                         I32 *minlenp, I32 *deltap,
-                       regnode *last, scan_data_t *data, U32 flags, U32 depth)
+                       regnode *last,
+                       scan_data_t *data,
+                       I32 stopparen,
+                       U8* recursed,
+                       struct regnode_charclass_class *and_withp,
+                       U32 flags, U32 depth)
                        /* scanp: Start here (read-write). */
                        /* deltap: Write maxlen-minlen here. */
                        /* last: Stop before this one. */
+                       /* data: string data about the pattern */
+                       /* stopparen: treat close N as END */
+                       /* recursed: which subroutines have we recursed into */
+                       /* and_withp: Valid if flags & SCF_DO_STCLASS_OR */
 {
     dVAR;
     I32 min = 0, pars = 0, code;
@@ -2257,1204 +2325,1305 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
     int is_inf_internal = 0;           /* The studied chunk is infinite */
     I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
     scan_data_t data_fake;
-    struct regnode_charclass_class and_with; /* Valid if flags & SCF_DO_STCLASS_OR */
     SV *re_trie_maxbuff = NULL;
     regnode *first_non_open = scan;
-
-
+    I32 stopmin = I32_MAX;
+    scan_frame last_frame= { last, NULL, NULL, stopparen };
+    scan_frame *frame=&last_frame;
+    
     GET_RE_DEBUG_FLAGS_DECL;
+    
 #ifdef DEBUGGING
-    StructCopy(&zero_scan_data, &data_fake, scan_data_t);    
+    StructCopy(&zero_scan_data, &data_fake, scan_data_t);
 #endif
+
     if ( depth == 0 ) {
-        while (first_non_open && OP(first_non_open) == OPEN) 
+        while (first_non_open && OP(first_non_open) == OPEN)
             first_non_open=regnext(first_non_open);
     }
 
+    while (frame) {
+
+       DEBUG_PEEP("FBEG",scan,depth);
+       while ( scan && OP(scan) != END && scan < frame->last ) {
+           /* Peephole optimizer: */
+           DEBUG_STUDYDATA(data,depth);
+           DEBUG_PEEP("Peep",scan,depth);
+           JOIN_EXACT(scan,&min,0);
+
+           /* Follow the next-chain of the current node and optimize
+              away all the NOTHINGs from it.  */
+           if (OP(scan) != CURLYX) {
+               const int max = (reg_off_by_arg[OP(scan)]
+                       ? I32_MAX
+                       /* I32 may be smaller than U16 on CRAYs! */
+                       : (I32_MAX < U16_MAX ? I32_MAX : U16_MAX));
+               int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
+               int noff;
+               regnode *n = scan;
+
+               /* Skip NOTHING and LONGJMP. */
+               while ((n = regnext(n))
+                       && ((PL_regkind[OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
+                           || ((OP(n) == LONGJMP) && (noff = ARG(n))))
+                       && off + noff < max)
+                   off += noff;
+               if (reg_off_by_arg[OP(scan)])
+                   ARG(scan) = off;
+               else
+                   NEXT_OFF(scan) = off;
+           }
 
-    while (scan && OP(scan) != END && scan < last) {
-       /* Peephole optimizer: */
-       DEBUG_STUDYDATA(data,depth);
-       DEBUG_PEEP("Peep",scan,depth);
-        JOIN_EXACT(scan,&min,0);
-
-       /* Follow the next-chain of the current node and optimize
-          away all the NOTHINGs from it.  */
-       if (OP(scan) != CURLYX) {
-           const int max = (reg_off_by_arg[OP(scan)]
-                      ? I32_MAX
-                      /* I32 may be smaller than U16 on CRAYs! */
-                      : (I32_MAX < U16_MAX ? I32_MAX : U16_MAX));
-           int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
-           int noff;
-           regnode *n = scan;
-       
-           /* Skip NOTHING and LONGJMP. */
-           while ((n = regnext(n))
-                  && ((PL_regkind[OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
-                      || ((OP(n) == LONGJMP) && (noff = ARG(n))))
-                  && off + noff < max)
-               off += noff;
-           if (reg_off_by_arg[OP(scan)])
-               ARG(scan) = off;
-           else
-               NEXT_OFF(scan) = off;
-       }
-
-
-
-       /* The principal pseudo-switch.  Cannot be a switch, since we
-          look into several different things.  */
-       if (OP(scan) == BRANCH || OP(scan) == BRANCHJ
-                  || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
-           next = regnext(scan);
-           code = OP(scan);
-           /* demq: the op(next)==code check is to see if we have "branch-branch" AFAICT */
-       
-           if (OP(next) == code || code == IFTHEN || code == SUSPEND) {
-               /* NOTE - There is similar code to this block below for handling
-                  TRIE nodes on a re-study.  If you change stuff here check there
-                  too. */
-               I32 max1 = 0, min1 = I32_MAX, num = 0;
-               struct regnode_charclass_class accum;
-               regnode * const startbranch=scan;
-               
-               if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
-                   scan_commit(pRExC_state, data, minlenp); /* Cannot merge strings after this. */
-               if (flags & SCF_DO_STCLASS)
-                   cl_init_zero(pRExC_state, &accum);
+           /* The principal pseudo-switch.  Cannot be a switch, since we
+              look into several different things.  */
+           if (OP(scan) == BRANCH || OP(scan) == BRANCHJ
+                   || OP(scan) == IFTHEN) {
+               next = regnext(scan);
+               code = OP(scan);
+               /* demq: the op(next)==code check is to see if we have "branch-branch" AFAICT */
+
+               if (OP(next) == code || code == IFTHEN) {
+                   /* NOTE - There is similar code to this block below for handling
+                      TRIE nodes on a re-study.  If you change stuff here check there
+                      too. */
+                   I32 max1 = 0, min1 = I32_MAX, num = 0;
+                   struct regnode_charclass_class accum;
+                   regnode * const startbranch=scan;
+
+                   if (flags & SCF_DO_SUBSTR)
+                       scan_commit(pRExC_state, data, minlenp); /* Cannot merge strings after this. */
+                   if (flags & SCF_DO_STCLASS)
+                       cl_init_zero(pRExC_state, &accum);
 
-               while (OP(scan) == code) {
-                   I32 deltanext, minnext, f = 0, fake;
-                   struct regnode_charclass_class this_class;
+                   while (OP(scan) == code) {
+                       I32 deltanext, minnext, f = 0, fake;
+                       struct regnode_charclass_class this_class;
 
-                   num++;
-                   data_fake.flags = 0;
-                   if (data) {         
-                       data_fake.whilem_c = data->whilem_c;
-                       data_fake.last_closep = data->last_closep;
-                   }
-                   else
-                       data_fake.last_closep = &fake;
-                   next = regnext(scan);
-                   scan = NEXTOPER(scan);
-                   if (code != BRANCH)
+                       num++;
+                       data_fake.flags = 0;
+                       if (data) {
+                           data_fake.whilem_c = data->whilem_c;
+                           data_fake.last_closep = data->last_closep;
+                       }
+                       else
+                           data_fake.last_closep = &fake;
+                       next = regnext(scan);
                        scan = NEXTOPER(scan);
-                   if (flags & SCF_DO_STCLASS) {
-                       cl_init(pRExC_state, &this_class);
-                       data_fake.start_class = &this_class;
-                       f = SCF_DO_STCLASS_AND;
-                   }           
-                   if (flags & SCF_WHILEM_VISITED_POS)
-                       f |= SCF_WHILEM_VISITED_POS;
-
-                   /* we suppose the run is continuous, last=next...*/
-                   minnext = study_chunk(pRExC_state, &scan, minlenp, &deltanext,
-                                         next, &data_fake, f,depth+1);
-                   if (min1 > minnext)
-                       min1 = minnext;
-                   if (max1 < minnext + deltanext)
-                       max1 = minnext + deltanext;
-                   if (deltanext == I32_MAX)
-                       is_inf = is_inf_internal = 1;
-                   scan = next;
-                   if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
-                       pars++;
-                   if (data) {
-                       if (data_fake.flags & SF_HAS_EVAL)
-                           data->flags |= SF_HAS_EVAL;
-                       data->whilem_c = data_fake.whilem_c;
+                       if (code != BRANCH)
+                           scan = NEXTOPER(scan);
+                       if (flags & SCF_DO_STCLASS) {
+                           cl_init(pRExC_state, &this_class);
+                           data_fake.start_class = &this_class;
+                           f = SCF_DO_STCLASS_AND;
+                       }
+                       if (flags & SCF_WHILEM_VISITED_POS)
+                           f |= SCF_WHILEM_VISITED_POS;
+
+                       /* we suppose the run is continuous, last=next...*/
+                       minnext = study_chunk(pRExC_state, &scan, minlenp, &deltanext,
+                               next, &data_fake,
+                               stopparen, recursed, NULL, f,depth+1);
+                       if (min1 > minnext)
+                           min1 = minnext;
+                       if (max1 < minnext + deltanext)
+                           max1 = minnext + deltanext;
+                       if (deltanext == I32_MAX)
+                           is_inf = is_inf_internal = 1;
+                       scan = next;
+                       if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
+                           pars++;
+                       if (data_fake.flags & SCF_SEEN_ACCEPT) {
+                           if ( stopmin > minnext)
+                               stopmin = min + min1;
+                           flags &= ~SCF_DO_SUBSTR;
+                           if (data)
+                               data->flags |= SCF_SEEN_ACCEPT;
+                       }
+                       if (data) {
+                           if (data_fake.flags & SF_HAS_EVAL)
+                               data->flags |= SF_HAS_EVAL;
+                           data->whilem_c = data_fake.whilem_c;
+                       }
+                       if (flags & SCF_DO_STCLASS)
+                           cl_or(pRExC_state, &accum, &this_class);
                    }
-                   if (flags & SCF_DO_STCLASS)
-                       cl_or(pRExC_state, &accum, &this_class);
-                   if (code == SUSPEND)
-                       break;
-               }
-               if (code == IFTHEN && num < 2) /* Empty ELSE branch */
-                   min1 = 0;
-               if (flags & SCF_DO_SUBSTR) {
-                   data->pos_min += min1;
-                   data->pos_delta += max1 - min1;
-                   if (max1 != min1 || is_inf)
-                       data->longest = &(data->longest_float);
-               }
-               min += min1;
-               delta += max1 - min1;
-               if (flags & SCF_DO_STCLASS_OR) {
-                   cl_or(pRExC_state, data->start_class, &accum);
-                   if (min1) {
-                       cl_and(data->start_class, &and_with);
-                       flags &= ~SCF_DO_STCLASS;
+                   if (code == IFTHEN && num < 2) /* Empty ELSE branch */
+                       min1 = 0;
+                   if (flags & SCF_DO_SUBSTR) {
+                       data->pos_min += min1;
+                       data->pos_delta += max1 - min1;
+                       if (max1 != min1 || is_inf)
+                           data->longest = &(data->longest_float);
                    }
-               }
-               else if (flags & SCF_DO_STCLASS_AND) {
-                   if (min1) {
-                       cl_and(data->start_class, &accum);
-                       flags &= ~SCF_DO_STCLASS;
+                   min += min1;
+                   delta += max1 - min1;
+                   if (flags & SCF_DO_STCLASS_OR) {
+                       cl_or(pRExC_state, data->start_class, &accum);
+                       if (min1) {
+                           cl_and(data->start_class, and_withp);
+                           flags &= ~SCF_DO_STCLASS;
+                       }
                    }
-                   else {
-                       /* Switch to OR mode: cache the old value of
-                        * data->start_class */
-                       StructCopy(data->start_class, &and_with,
-                                  struct regnode_charclass_class);
-                       flags &= ~SCF_DO_STCLASS_AND;
-                       StructCopy(&accum, data->start_class,
-                                  struct regnode_charclass_class);
-                       flags |= SCF_DO_STCLASS_OR;
-                       data->start_class->flags |= ANYOF_EOS;
+                   else if (flags & SCF_DO_STCLASS_AND) {
+                       if (min1) {
+                           cl_and(data->start_class, &accum);
+                           flags &= ~SCF_DO_STCLASS;
+                       }
+                       else {
+                           /* Switch to OR mode: cache the old value of
+                            * data->start_class */
+                           INIT_AND_WITHP;
+                           StructCopy(data->start_class, and_withp,
+                                   struct regnode_charclass_class);
+                           flags &= ~SCF_DO_STCLASS_AND;
+                           StructCopy(&accum, data->start_class,
+                                   struct regnode_charclass_class);
+                           flags |= SCF_DO_STCLASS_OR;
+                           data->start_class->flags |= ANYOF_EOS;
+                       }
                    }
-               }
 
-                if (PERL_ENABLE_TRIE_OPTIMISATION && OP( startbranch ) == BRANCH ) {
-               /* demq.
+                   if (PERL_ENABLE_TRIE_OPTIMISATION && OP( startbranch ) == BRANCH ) {
+                       /* demq.
 
-                  Assuming this was/is a branch we are dealing with: 'scan' now
-                  points at the item that follows the branch sequence, whatever
-                  it is. We now start at the beginning of the sequence and look
-                  for subsequences of
+                          Assuming this was/is a branch we are dealing with: 'scan' now
+                          points at the item that follows the branch sequence, whatever
+                          it is. We now start at the beginning of the sequence and look
+                          for subsequences of
 
-                  BRANCH->EXACT=>x1
-                  BRANCH->EXACT=>x2
-                  tail
+                          BRANCH->EXACT=>x1
+                          BRANCH->EXACT=>x2
+                          tail
 
-                  which would be constructed from a pattern like /A|LIST|OF|WORDS/
+                          which would be constructed from a pattern like /A|LIST|OF|WORDS/
 
-                  If we can find such a subseqence we need to turn the first
-                  element into a trie and then add the subsequent branch exact
-                  strings to the trie.
+                          If we can find such a subseqence we need to turn the first
+                          element into a trie and then add the subsequent branch exact
+                          strings to the trie.
 
-                  We have two cases
+                          We have two cases
 
-                    1. patterns where the whole set of branch can be converted. 
+                          1. patterns where the whole set of branch can be converted. 
 
-                    2. patterns where only a subset can be converted.
+                          2. patterns where only a subset can be converted.
 
-                  In case 1 we can replace the whole set with a single regop
-                  for the trie. In case 2 we need to keep the start and end
-                  branchs so
+                          In case 1 we can replace the whole set with a single regop
+                          for the trie. In case 2 we need to keep the start and end
+                          branchs so
 
-                    'BRANCH EXACT; BRANCH EXACT; BRANCH X'
-                    becomes BRANCH TRIE; BRANCH X;
+                          'BRANCH EXACT; BRANCH EXACT; BRANCH X'
+                          becomes BRANCH TRIE; BRANCH X;
 
-                 There is an additional case, that being where there is a 
-                 common prefix, which gets split out into an EXACT like node
-                 preceding the TRIE node.
+                          There is an additional case, that being where there is a 
+                          common prefix, which gets split out into an EXACT like node
+                          preceding the TRIE node.
 
-                 If x(1..n)==tail then we can do a simple trie, if not we make
-                 a "jump" trie, such that when we match the appropriate word
-                 we "jump" to the appopriate tail node. Essentailly we turn
-                 a nested if into a case structure of sorts.
+                          If x(1..n)==tail then we can do a simple trie, if not we make
+                          a "jump" trie, such that when we match the appropriate word
+                          we "jump" to the appopriate tail node. Essentailly we turn
+                          a nested if into a case structure of sorts.
 
-               */
-               
-                   int made=0;
-                   if (!re_trie_maxbuff) {
-                       re_trie_maxbuff = get_sv(RE_TRIE_MAXBUF_NAME, 1);
-                       if (!SvIOK(re_trie_maxbuff))
-                           sv_setiv(re_trie_maxbuff, RE_TRIE_MAXBUF_INIT);
-                   }
-                    if ( SvIV(re_trie_maxbuff)>=0  ) {
-                        regnode *cur;
-                        regnode *first = (regnode *)NULL;
-                        regnode *last = (regnode *)NULL;
-                        regnode *tail = scan;
-                        U8 optype = 0;
-                        U32 count=0;
+                       */
+
+                       int made=0;
+                       if (!re_trie_maxbuff) {
+                           re_trie_maxbuff = get_sv(RE_TRIE_MAXBUF_NAME, 1);
+                           if (!SvIOK(re_trie_maxbuff))
+                               sv_setiv(re_trie_maxbuff, RE_TRIE_MAXBUF_INIT);
+                       }
+                       if ( SvIV(re_trie_maxbuff)>=0  ) {
+                           regnode *cur;
+                           regnode *first = (regnode *)NULL;
+                           regnode *last = (regnode *)NULL;
+                           regnode *tail = scan;
+                           U8 optype = 0;
+                           U32 count=0;
 
 #ifdef DEBUGGING
-                        SV * const mysv = sv_newmortal();       /* for dumping */
+                           SV * const mysv = sv_newmortal();       /* for dumping */
 #endif
-                        /* var tail is used because there may be a TAIL
-                           regop in the way. Ie, the exacts will point to the
-                           thing following the TAIL, but the last branch will
-                           point at the TAIL. So we advance tail. If we
-                           have nested (?:) we may have to move through several
-                           tails.
-                         */
-
-                        while ( OP( tail ) == TAIL ) {
-                            /* this is the TAIL generated by (?:) */
-                            tail = regnext( tail );
-                        }
+                           /* var tail is used because there may be a TAIL
+                              regop in the way. Ie, the exacts will point to the
+                              thing following the TAIL, but the last branch will
+                              point at the TAIL. So we advance tail. If we
+                              have nested (?:) we may have to move through several
+                              tails.
+                              */
+
+                           while ( OP( tail ) == TAIL ) {
+                               /* this is the TAIL generated by (?:) */
+                               tail = regnext( tail );
+                           }
 
-                        
-                        DEBUG_OPTIMISE_r({
-                            regprop(RExC_rx, mysv, tail );
-                            PerlIO_printf( Perl_debug_log, "%*s%s%s\n",
-                                (int)depth * 2 + 2, "", 
-                                "Looking for TRIE'able sequences. Tail node is: ", 
-                                SvPV_nolen_const( mysv )
-                            );
-                        });
-                        
-                        /*
-
-                           step through the branches, cur represents each
-                           branch, noper is the first thing to be matched
-                           as part of that branch and noper_next is the
-                           regnext() of that node. if noper is an EXACT
-                           and noper_next is the same as scan (our current
-                           position in the regex) then the EXACT branch is
-                           a possible optimization target. Once we have
-                           two or more consequetive such branches we can
-                           create a trie of the EXACT's contents and stich
-                           it in place. If the sequence represents all of
-                           the branches we eliminate the whole thing and
-                           replace it with a single TRIE. If it is a
-                           subsequence then we need to stitch it in. This
-                           means the first branch has to remain, and needs
-                           to be repointed at the item on the branch chain
-                           following the last branch optimized. This could
-                           be either a BRANCH, in which case the
-                           subsequence is internal, or it could be the
-                           item following the branch sequence in which
-                           case the subsequence is at the end.
-
-                        */
-
-                        /* dont use tail as the end marker for this traverse */
-                        for ( cur = startbranch ; cur != scan ; cur = regnext( cur ) ) {
-                            regnode * const noper = NEXTOPER( cur );
-#if defined(DEBUGGING) || defined(NOJUMPTRIE)
-                            regnode * const noper_next = regnext( noper );
-#endif
 
-                            DEBUG_OPTIMISE_r({
-                                regprop(RExC_rx, mysv, cur);
-                                PerlIO_printf( Perl_debug_log, "%*s- %s (%d)",
-                                   (int)depth * 2 + 2,"", SvPV_nolen_const( mysv ), REG_NODE_NUM(cur) );
+                           DEBUG_OPTIMISE_r({
+                                   regprop(RExC_rx, mysv, tail );
+                                   PerlIO_printf( Perl_debug_log, "%*s%s%s\n",
+                                       (int)depth * 2 + 2, "", 
+                                       "Looking for TRIE'able sequences. Tail node is: ", 
+                                       SvPV_nolen_const( mysv )
+                                       );
+                                   });
+
+                           /*
+
+                              step through the branches, cur represents each
+                              branch, noper is the first thing to be matched
+                              as part of that branch and noper_next is the
+                              regnext() of that node. if noper is an EXACT
+                              and noper_next is the same as scan (our current
+                              position in the regex) then the EXACT branch is
+                              a possible optimization target. Once we have
+                              two or more consequetive such branches we can
+                              create a trie of the EXACT's contents and stich
+                              it in place. If the sequence represents all of
+                              the branches we eliminate the whole thing and
+                              replace it with a single TRIE. If it is a
+                              subsequence then we need to stitch it in. This
+                              means the first branch has to remain, and needs
+                              to be repointed at the item on the branch chain
+                              following the last branch optimized. This could
+                              be either a BRANCH, in which case the
+                              subsequence is internal, or it could be the
+                              item following the branch sequence in which
+                              case the subsequence is at the end.
 
-                                regprop(RExC_rx, mysv, noper);
-                                PerlIO_printf( Perl_debug_log, " -> %s",
-                                    SvPV_nolen_const(mysv));
+*/
 
-                                if ( noper_next ) {
-                                  regprop(RExC_rx, mysv, noper_next );
-                                  PerlIO_printf( Perl_debug_log,"\t=> %s\t",
-                                    SvPV_nolen_const(mysv));
-                                }
-                                PerlIO_printf( Perl_debug_log, "(First==%d,Last==%d,Cur==%d)\n",
-                                   REG_NODE_NUM(first), REG_NODE_NUM(last), REG_NODE_NUM(cur) );
-                            });
-                            if ( (((first && optype!=NOTHING) ? OP( noper ) == optype
-                                         : PL_regkind[ OP( noper ) ] == EXACT )
-                                  || OP(noper) == NOTHING )
+                           /* dont use tail as the end marker for this traverse */
+                           for ( cur = startbranch ; cur != scan ; cur = regnext( cur ) ) {
+                               regnode * const noper = NEXTOPER( cur );
+#if defined(DEBUGGING) || defined(NOJUMPTRIE)
+                               regnode * const noper_next = regnext( noper );
+#endif
+
+                               DEBUG_OPTIMISE_r({
+                                   regprop(RExC_rx, mysv, cur);
+                                   PerlIO_printf( Perl_debug_log, "%*s- %s (%d)",
+                                       (int)depth * 2 + 2,"", SvPV_nolen_const( mysv ), REG_NODE_NUM(cur) );
+
+                                   regprop(RExC_rx, mysv, noper);
+                                   PerlIO_printf( Perl_debug_log, " -> %s",
+                                       SvPV_nolen_const(mysv));
+
+                                   if ( noper_next ) {
+                                       regprop(RExC_rx, mysv, noper_next );
+                                       PerlIO_printf( Perl_debug_log,"\t=> %s\t",
+                                           SvPV_nolen_const(mysv));
+                                   }
+                                   PerlIO_printf( Perl_debug_log, "(First==%d,Last==%d,Cur==%d)\n",
+                                       REG_NODE_NUM(first), REG_NODE_NUM(last), REG_NODE_NUM(cur) );
+                               });
+                               if ( (((first && optype!=NOTHING) ? OP( noper ) == optype
+                                               : PL_regkind[ OP( noper ) ] == EXACT )
+                                           || OP(noper) == NOTHING )
 #ifdef NOJUMPTRIE
-                                  && noper_next == tail
+                                       && noper_next == tail
 #endif
-                                  && count < U16_MAX)
-                            {
-                                count++;
-                                if ( !first || optype == NOTHING ) {
-                                    if (!first) first = cur;
-                                    optype = OP( noper );
-                                } else {
-                                    last = cur;
-                                }
-                            } else {
-                                if ( last ) {
-                                    make_trie( pRExC_state, 
-                                            startbranch, first, cur, tail, count, 
-                                            optype, depth+1 );
-                                }
-                                if ( PL_regkind[ OP( noper ) ] == EXACT
+                                       && count < U16_MAX)
+                               {
+                                   count++;
+                                   if ( !first || optype == NOTHING ) {
+                                       if (!first) first = cur;
+                                       optype = OP( noper );
+                                   } else {
+                                       last = cur;
+                                   }
+                               } else {
+                                   if ( last ) {
+                                       make_trie( pRExC_state,
+                                               startbranch, first, cur, tail, count,
+                                               optype, depth+1 );
+                                   }
+                                   if ( PL_regkind[ OP( noper ) ] == EXACT
 #ifdef NOJUMPTRIE
-                                     && noper_next == tail
+                                           && noper_next == tail
 #endif
-                                ){
-                                    count = 1;
-                                    first = cur;
-                                    optype = OP( noper );
-                                } else {
-                                    count = 0;
-                                    first = NULL;
-                                    optype = 0;
-                                }
-                                last = NULL;
-                            }
-                        }
-                        DEBUG_OPTIMISE_r({
-                            regprop(RExC_rx, mysv, cur);
-                            PerlIO_printf( Perl_debug_log,
-                              "%*s- %s (%d) <SCAN FINISHED>\n", (int)depth * 2 + 2,
-                              "", SvPV_nolen_const( mysv ),REG_NODE_NUM(cur));
-
-                        });
-                        if ( last ) {
-                            made= make_trie( pRExC_state, startbranch, first, scan, tail, count, optype, depth+1 );
+                                       ) {
+                                       count = 1;
+                                       first = cur;
+                                       optype = OP( noper );
+                                   } else {
+                                       count = 0;
+                                       first = NULL;
+                                       optype = 0;
+                                   }
+                                   last = NULL;
+                               }
+                           }
+                           DEBUG_OPTIMISE_r({
+                                   regprop(RExC_rx, mysv, cur);
+                                   PerlIO_printf( Perl_debug_log,
+                                       "%*s- %s (%d) <SCAN FINISHED>\n", (int)depth * 2 + 2,
+                                       "", SvPV_nolen_const( mysv ),REG_NODE_NUM(cur));
+
+                                   });
+                           if ( last ) {
+                               made= make_trie( pRExC_state, startbranch, first, scan, tail, count, optype, depth+1 );
 #ifdef TRIE_STUDY_OPT  
-                            if ( ((made == MADE_EXACT_TRIE && 
-                                 startbranch == first) 
-                                 || ( first_non_open == first )) && 
-                                 depth==0 ) 
-                                flags |= SCF_TRIE_RESTUDY;
+                               if ( ((made == MADE_EXACT_TRIE &&
+                                               startbranch == first)
+                                           || ( first_non_open == first )) &&
+                                       depth==0 ) {
+                                   flags |= SCF_TRIE_RESTUDY;
+                                   if ( startbranch == first
+                                           && scan == tail )
+                                   {
+                                       RExC_seen &=~REG_TOP_LEVEL_BRANCHES;
+                                   }
+                               }
 #endif
-                        }
-                    }
-                    
-                } /* do trie */
-                
-           }
-           else if ( code == BRANCHJ ) {  /* single branch is optimized. */
-               scan = NEXTOPER(NEXTOPER(scan));
-           } else                      /* single branch is optimized. */
-               scan = NEXTOPER(scan);
-           continue;
-       }
-       else if (OP(scan) == EXACT) {
-           I32 l = STR_LEN(scan);
-           UV uc;
-           if (UTF) {
-               const U8 * const s = (U8*)STRING(scan);
-               l = utf8_length(s, s + l);
-               uc = utf8_to_uvchr(s, NULL);
-           } else {
-               uc = *((U8*)STRING(scan));
-           }
-           min += l;
-           if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
-               /* The code below prefers earlier match for fixed
-                  offset, later match for variable offset.  */
-               if (data->last_end == -1) { /* Update the start info. */
-                   data->last_start_min = data->pos_min;
-                   data->last_start_max = is_inf
-                       ? I32_MAX : data->pos_min + data->pos_delta;
+                           }
+                       }
+
+                   } /* do trie */
+
                }
-               sv_catpvn(data->last_found, STRING(scan), STR_LEN(scan));
-               if (UTF)
-                   SvUTF8_on(data->last_found);
-               {
-                   SV * const sv = data->last_found;
-                   MAGIC * const mg = SvUTF8(sv) && SvMAGICAL(sv) ?
-                       mg_find(sv, PERL_MAGIC_utf8) : NULL;
-                   if (mg && mg->mg_len >= 0)
-                       mg->mg_len += utf8_length((U8*)STRING(scan),
-                                                 (U8*)STRING(scan)+STR_LEN(scan));
+               else if ( code == BRANCHJ ) {  /* single branch is optimized. */
+                   scan = NEXTOPER(NEXTOPER(scan));
+               } else                  /* single branch is optimized. */
+                   scan = NEXTOPER(scan);
+               continue;
+           } else if (OP(scan) == SUSPEND || OP(scan) == GOSUB || OP(scan) == GOSTART) {
+               scan_frame *newframe = NULL;
+               I32 paren;
+               regnode *start;
+               regnode *end;
+
+               if (OP(scan) != SUSPEND) {
+                   /* set the pointer */
+                   if (OP(scan) == GOSUB) {
+                       paren = ARG(scan);
+                       RExC_recurse[ARG2L(scan)] = scan;
+                       start = RExC_open_parens[paren-1];
+                       end   = RExC_close_parens[paren-1];
+                   } else {
+                       paren = 0;
+                       start = RExC_rx->program + 1;
+                       end   = RExC_opend;
+                   }
+                   if (!recursed) {
+                       Newxz(recursed, (((RExC_npar)>>3) +1), U8);
+                       SAVEFREEPV(recursed);
+                   }
+                   if (!PAREN_TEST(recursed,paren+1)) {
+                       PAREN_SET(recursed,paren+1);
+                       Newx(newframe,1,scan_frame);
+                   } else {
+                       if (flags & SCF_DO_SUBSTR) {
+                           scan_commit(pRExC_state,data,minlenp);
+                           data->longest = &(data->longest_float);
+                       }
+                       is_inf = is_inf_internal = 1;
+                       if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
+                           cl_anything(pRExC_state, data->start_class);
+                       flags &= ~SCF_DO_STCLASS;
+                   }
+               } else {             
+                   Newx(newframe,1,scan_frame);
+                   paren = stopparen;
+                   start = scan+2;
+                   end = regnext(scan);
                }
-               data->last_end = data->pos_min + l;
-               data->pos_min += l; /* As in the first entry. */
-               data->flags &= ~SF_BEFORE_EOL;
-           }
-           if (flags & SCF_DO_STCLASS_AND) {
-               /* Check whether it is compatible with what we know already! */
-               int compat = 1;
-
-               if (uc >= 0x100 ||
-                   (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
-                   && !ANYOF_BITMAP_TEST(data->start_class, uc)
-                   && (!(data->start_class->flags & ANYOF_FOLD)
-                       || !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
-                    )
-                   compat = 0;
-               ANYOF_CLASS_ZERO(data->start_class);
-               ANYOF_BITMAP_ZERO(data->start_class);
-               if (compat)
-                   ANYOF_BITMAP_SET(data->start_class, uc);
-               data->start_class->flags &= ~ANYOF_EOS;
-               if (uc < 0x100)
-                 data->start_class->flags &= ~ANYOF_UNICODE_ALL;
-           }
-           else if (flags & SCF_DO_STCLASS_OR) {
-               /* false positive possible if the class is case-folded */
-               if (uc < 0x100)
-                   ANYOF_BITMAP_SET(data->start_class, uc);
-               else
-                   data->start_class->flags |= ANYOF_UNICODE_ALL;
-               data->start_class->flags &= ~ANYOF_EOS;
-               cl_and(data->start_class, &and_with);
-           }
-           flags &= ~SCF_DO_STCLASS;
-       }
-       else if (PL_regkind[OP(scan)] == EXACT) { /* But OP != EXACT! */
-           I32 l = STR_LEN(scan);
-           UV uc = *((U8*)STRING(scan));
-
-           /* Search for fixed substrings supports EXACT only. */
-           if (flags & SCF_DO_SUBSTR) {
-               assert(data);
-               scan_commit(pRExC_state, data, minlenp);
+               if (newframe) {
+                   assert(start);
+                   assert(end);
+                   SAVEFREEPV(newframe);
+                   newframe->next = regnext(scan);
+                   newframe->last = end;
+                   newframe->stop = stopparen;
+                   newframe->prev = frame;
+                   frame = newframe;
+                   scan =  start;
+                   stopparen = paren;
+                   continue;
+               } 
            }
-           if (UTF) {
-               const U8 * const s = (U8 *)STRING(scan);
-               l = utf8_length(s, s + l);
-               uc = utf8_to_uvchr(s, NULL);
-           }
-           min += l;
-           if (flags & SCF_DO_SUBSTR)
-               data->pos_min += l;
-           if (flags & SCF_DO_STCLASS_AND) {
-               /* Check whether it is compatible with what we know already! */
-               int compat = 1;
-
-               if (uc >= 0x100 ||
-                   (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
-                   && !ANYOF_BITMAP_TEST(data->start_class, uc)
-                    && !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
-                   compat = 0;
-               ANYOF_CLASS_ZERO(data->start_class);
-               ANYOF_BITMAP_ZERO(data->start_class);
-               if (compat) {
-                   ANYOF_BITMAP_SET(data->start_class, uc);
+           else if (OP(scan) == EXACT) {
+               I32 l = STR_LEN(scan);
+               UV uc;
+               if (UTF) {
+                   const U8 * const s = (U8*)STRING(scan);
+                   l = utf8_length(s, s + l);
+                   uc = utf8_to_uvchr(s, NULL);
+               } else {
+                   uc = *((U8*)STRING(scan));
+               }
+               min += l;
+               if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
+                   /* The code below prefers earlier match for fixed
+                      offset, later match for variable offset.  */
+                   if (data->last_end == -1) { /* Update the start info. */
+                       data->last_start_min = data->pos_min;
+                       data->last_start_max = is_inf
+                           ? I32_MAX : data->pos_min + data->pos_delta;
+                   }
+                   sv_catpvn(data->last_found, STRING(scan), STR_LEN(scan));
+                   if (UTF)
+                       SvUTF8_on(data->last_found);
+                   {
+                       SV * const sv = data->last_found;
+                       MAGIC * const mg = SvUTF8(sv) && SvMAGICAL(sv) ?
+                           mg_find(sv, PERL_MAGIC_utf8) : NULL;
+                       if (mg && mg->mg_len >= 0)
+                           mg->mg_len += utf8_length((U8*)STRING(scan),
+                                   (U8*)STRING(scan)+STR_LEN(scan));
+                   }
+                   data->last_end = data->pos_min + l;
+                   data->pos_min += l; /* As in the first entry. */
+                   data->flags &= ~SF_BEFORE_EOL;
+               }
+               if (flags & SCF_DO_STCLASS_AND) {
+                   /* Check whether it is compatible with what we know already! */
+                   int compat = 1;
+
+                   if (uc >= 0x100 ||
+                           (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
+                            && !ANYOF_BITMAP_TEST(data->start_class, uc)
+                            && (!(data->start_class->flags & ANYOF_FOLD)
+                                || !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
+                      )
+                       compat = 0;
+                   ANYOF_CLASS_ZERO(data->start_class);
+                   ANYOF_BITMAP_ZERO(data->start_class);
+                   if (compat)
+                       ANYOF_BITMAP_SET(data->start_class, uc);
                    data->start_class->flags &= ~ANYOF_EOS;
-                   data->start_class->flags |= ANYOF_FOLD;
-                   if (OP(scan) == EXACTFL)
-                       data->start_class->flags |= ANYOF_LOCALE;
+                   if (uc < 0x100)
+                       data->start_class->flags &= ~ANYOF_UNICODE_ALL;
                }
-           }
-           else if (flags & SCF_DO_STCLASS_OR) {
-               if (data->start_class->flags & ANYOF_FOLD) {
-                   /* false positive possible if the class is case-folded.
-                      Assume that the locale settings are the same... */
+               else if (flags & SCF_DO_STCLASS_OR) {
+                   /* false positive possible if the class is case-folded */
                    if (uc < 0x100)
                        ANYOF_BITMAP_SET(data->start_class, uc);
+                   else
+                       data->start_class->flags |= ANYOF_UNICODE_ALL;
                    data->start_class->flags &= ~ANYOF_EOS;
+                   cl_and(data->start_class, and_withp);
                }
-               cl_and(data->start_class, &and_with);
+               flags &= ~SCF_DO_STCLASS;
            }
-           flags &= ~SCF_DO_STCLASS;
-       }
-       else if (strchr((const char*)PL_varies,OP(scan))) {
-           I32 mincount, maxcount, minnext, deltanext, fl = 0;
-           I32 f = flags, pos_before = 0;
-           regnode * const oscan = scan;
-           struct regnode_charclass_class this_class;
-           struct regnode_charclass_class *oclass = NULL;
-           I32 next_is_eval = 0;
-
-           switch (PL_regkind[OP(scan)]) {
-           case WHILEM:                /* End of (?:...)* . */
-               scan = NEXTOPER(scan);
-               goto finish;
-           case PLUS:
-               if (flags & (SCF_DO_SUBSTR | SCF_DO_STCLASS)) {
-                   next = NEXTOPER(scan);
-                   if (OP(next) == EXACT || (flags & SCF_DO_STCLASS)) {
-                       mincount = 1;
-                       maxcount = REG_INFTY;
-                       next = regnext(scan);
-                       scan = NEXTOPER(scan);
-                       goto do_curly;
-                   }
-               }
-               if (flags & SCF_DO_SUBSTR)
-                   data->pos_min++;
-               min++;
-               /* Fall through. */
-           case STAR:
-               if (flags & SCF_DO_STCLASS) {
-                   mincount = 0;
-                   maxcount = REG_INFTY;
-                   next = regnext(scan);
-                   scan = NEXTOPER(scan);
-                   goto do_curly;
-               }
-               is_inf = is_inf_internal = 1;
-               scan = regnext(scan);
-               if (flags & SCF_DO_SUBSTR) {
-                   scan_commit(pRExC_state, data, minlenp); /* Cannot extend fixed substrings */
-                   data->longest = &(data->longest_float);
-               }
-               goto optimize_curly_tail;
-           case CURLY:
-               mincount = ARG1(scan);
-               maxcount = ARG2(scan);
-               next = regnext(scan);
-               if (OP(scan) == CURLYX) {
-                   I32 lp = (data ? *(data->last_closep) : 0);
-                   scan->flags = ((lp <= (I32)U8_MAX) ? (U8)lp : U8_MAX);
-               }
-               scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
-               next_is_eval = (OP(scan) == EVAL);
-             do_curly:
+           else if (PL_regkind[OP(scan)] == EXACT) { /* But OP != EXACT! */
+               I32 l = STR_LEN(scan);
+               UV uc = *((U8*)STRING(scan));
+
+               /* Search for fixed substrings supports EXACT only. */
                if (flags & SCF_DO_SUBSTR) {
-                   if (mincount == 0) scan_commit(pRExC_state,data,minlenp); /* Cannot extend fixed substrings */
-                   pos_before = data->pos_min;
-               }
-               if (data) {
-                   fl = data->flags;
-                   data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
-                   if (is_inf)
-                       data->flags |= SF_IS_INF;
+                   assert(data);
+                   scan_commit(pRExC_state, data, minlenp);
                }
-               if (flags & SCF_DO_STCLASS) {
-                   cl_init(pRExC_state, &this_class);
-                   oclass = data->start_class;
-                   data->start_class = &this_class;
-                   f |= SCF_DO_STCLASS_AND;
-                   f &= ~SCF_DO_STCLASS_OR;
+               if (UTF) {
+                   const U8 * const s = (U8 *)STRING(scan);
+                   l = utf8_length(s, s + l);
+                   uc = utf8_to_uvchr(s, NULL);
                }
-               /* These are the cases when once a subexpression
-                  fails at a particular position, it cannot succeed
-                  even after backtracking at the enclosing scope.
-               
-                  XXXX what if minimal match and we are at the
-                       initial run of {n,m}? */
-               if ((mincount != maxcount - 1) && (maxcount != REG_INFTY))
-                   f &= ~SCF_WHILEM_VISITED_POS;
-
-               /* This will finish on WHILEM, setting scan, or on NULL: */
-               minnext = study_chunk(pRExC_state, &scan, minlenp, &deltanext, last, data,
-                                     (mincount == 0
-                                       ? (f & ~SCF_DO_SUBSTR) : f),depth+1);
-
-               if (flags & SCF_DO_STCLASS)
-                   data->start_class = oclass;
-               if (mincount == 0 || minnext == 0) {
-                   if (flags & SCF_DO_STCLASS_OR) {
-                       cl_or(pRExC_state, data->start_class, &this_class);
-                   }
-                   else if (flags & SCF_DO_STCLASS_AND) {
-                       /* Switch to OR mode: cache the old value of
-                        * data->start_class */
-                       StructCopy(data->start_class, &and_with,
-                                  struct regnode_charclass_class);
-                       flags &= ~SCF_DO_STCLASS_AND;
-                       StructCopy(&this_class, data->start_class,
-                                  struct regnode_charclass_class);
-                       flags |= SCF_DO_STCLASS_OR;
-                       data->start_class->flags |= ANYOF_EOS;
-                   }
-               } else {                /* Non-zero len */
-                   if (flags & SCF_DO_STCLASS_OR) {
-                       cl_or(pRExC_state, data->start_class, &this_class);
-                       cl_and(data->start_class, &and_with);
+               min += l;
+               if (flags & SCF_DO_SUBSTR)
+                   data->pos_min += l;
+               if (flags & SCF_DO_STCLASS_AND) {
+                   /* Check whether it is compatible with what we know already! */
+                   int compat = 1;
+
+                   if (uc >= 0x100 ||
+                           (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
+                            && !ANYOF_BITMAP_TEST(data->start_class, uc)
+                            && !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
+                       compat = 0;
+                   ANYOF_CLASS_ZERO(data->start_class);
+                   ANYOF_BITMAP_ZERO(data->start_class);
+                   if (compat) {
+                       ANYOF_BITMAP_SET(data->start_class, uc);
+                       data->start_class->flags &= ~ANYOF_EOS;
+                       data->start_class->flags |= ANYOF_FOLD;
+                       if (OP(scan) == EXACTFL)
+                           data->start_class->flags |= ANYOF_LOCALE;
                    }
-                   else if (flags & SCF_DO_STCLASS_AND)
-                       cl_and(data->start_class, &this_class);
-                   flags &= ~SCF_DO_STCLASS;
                }
-               if (!scan)              /* It was not CURLYX, but CURLY. */
-                   scan = next;
-               if ( /* ? quantifier ok, except for (?{ ... }) */
-                   (next_is_eval || !(mincount == 0 && maxcount == 1))
-                   && (minnext == 0) && (deltanext == 0)
-                   && data && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
-                   && maxcount <= REG_INFTY/3 /* Complement check for big count */
-                   && ckWARN(WARN_REGEXP))
-               {
-                   vWARN(RExC_parse,
-                         "Quantifier unexpected on zero-length expression");
+               else if (flags & SCF_DO_STCLASS_OR) {
+                   if (data->start_class->flags & ANYOF_FOLD) {
+                       /* false positive possible if the class is case-folded.
+                          Assume that the locale settings are the same... */
+                       if (uc < 0x100)
+                           ANYOF_BITMAP_SET(data->start_class, uc);
+                       data->start_class->flags &= ~ANYOF_EOS;
+                   }
+                   cl_and(data->start_class, and_withp);
                }
+               flags &= ~SCF_DO_STCLASS;
+           }
+           else if (strchr((const char*)PL_varies,OP(scan))) {
+               I32 mincount, maxcount, minnext, deltanext, fl = 0;
+               I32 f = flags, pos_before = 0;
+               regnode * const oscan = scan;
+               struct regnode_charclass_class this_class;
+               struct regnode_charclass_class *oclass = NULL;
+               I32 next_is_eval = 0;
+
+               switch (PL_regkind[OP(scan)]) {
+                   case WHILEM:                /* End of (?:...)* . */
+                       scan = NEXTOPER(scan);
+                       goto finish;
+                   case PLUS:
+                       if (flags & (SCF_DO_SUBSTR | SCF_DO_STCLASS)) {
+                           next = NEXTOPER(scan);
+                           if (OP(next) == EXACT || (flags & SCF_DO_STCLASS)) {
+                               mincount = 1;
+                               maxcount = REG_INFTY;
+                               next = regnext(scan);
+                               scan = NEXTOPER(scan);
+                               goto do_curly;
+                           }
+                       }
+                       if (flags & SCF_DO_SUBSTR)
+                           data->pos_min++;
+                       min++;
+                       /* Fall through. */
+                   case STAR:
+                       if (flags & SCF_DO_STCLASS) {
+                           mincount = 0;
+                           maxcount = REG_INFTY;
+                           next = regnext(scan);
+                           scan = NEXTOPER(scan);
+                           goto do_curly;
+                       }
+                       is_inf = is_inf_internal = 1;
+                       scan = regnext(scan);
+                       if (flags & SCF_DO_SUBSTR) {
+                           scan_commit(pRExC_state, data, minlenp); /* Cannot extend fixed substrings */
+                           data->longest = &(data->longest_float);
+                       }
+                       goto optimize_curly_tail;
+                   case CURLY:
+                       if (stopparen>0 && (OP(scan)==CURLYN || OP(scan)==CURLYM)
+                               && (scan->flags == stopparen))
+                       {
+                           mincount = 1;
+                           maxcount = 1;
+                       } else {
+                           mincount = ARG1(scan);
+                           maxcount = ARG2(scan);
+                       }
+                       next = regnext(scan);
+                       if (OP(scan) == CURLYX) {
+                           I32 lp = (data ? *(data->last_closep) : 0);
+                           scan->flags = ((lp <= (I32)U8_MAX) ? (U8)lp : U8_MAX);
+                       }
+                       scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
+                       next_is_eval = (OP(scan) == EVAL);
+do_curly:
+                       if (flags & SCF_DO_SUBSTR) {
+                           if (mincount == 0) scan_commit(pRExC_state,data,minlenp); /* Cannot extend fixed substrings */
+                           pos_before = data->pos_min;
+                       }
+                       if (data) {
+                           fl = data->flags;
+                           data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
+                           if (is_inf)
+                               data->flags |= SF_IS_INF;
+                       }
+                       if (flags & SCF_DO_STCLASS) {
+                           cl_init(pRExC_state, &this_class);
+                           oclass = data->start_class;
+                           data->start_class = &this_class;
+                           f |= SCF_DO_STCLASS_AND;
+                           f &= ~SCF_DO_STCLASS_OR;
+                       }
+                       /* These are the cases when once a subexpression
+                          fails at a particular position, it cannot succeed
+                          even after backtracking at the enclosing scope.
+
+                          XXXX what if minimal match and we are at the
+                          initial run of {n,m}? */
+                       if ((mincount != maxcount - 1) && (maxcount != REG_INFTY))
+                           f &= ~SCF_WHILEM_VISITED_POS;
+
+                       /* This will finish on WHILEM, setting scan, or on NULL: */
+                       minnext = study_chunk(pRExC_state, &scan, minlenp, &deltanext, 
+                               last, data, stopparen, recursed, NULL,
+                               (mincount == 0
+                                ? (f & ~SCF_DO_SUBSTR) : f),depth+1);
+
+                       if (flags & SCF_DO_STCLASS)
+                           data->start_class = oclass;
+                       if (mincount == 0 || minnext == 0) {
+                           if (flags & SCF_DO_STCLASS_OR) {
+                               cl_or(pRExC_state, data->start_class, &this_class);
+                           }
+                           else if (flags & SCF_DO_STCLASS_AND) {
+                               /* Switch to OR mode: cache the old value of
+                                * data->start_class */
+                               INIT_AND_WITHP;
+                               StructCopy(data->start_class, and_withp,
+                                       struct regnode_charclass_class);
+                               flags &= ~SCF_DO_STCLASS_AND;
+                               StructCopy(&this_class, data->start_class,
+                                       struct regnode_charclass_class);
+                               flags |= SCF_DO_STCLASS_OR;
+                               data->start_class->flags |= ANYOF_EOS;
+                           }
+                       } else {                /* Non-zero len */
+                           if (flags & SCF_DO_STCLASS_OR) {
+                               cl_or(pRExC_state, data->start_class, &this_class);
+                               cl_and(data->start_class, and_withp);
+                           }
+                           else if (flags & SCF_DO_STCLASS_AND)
+                               cl_and(data->start_class, &this_class);
+                           flags &= ~SCF_DO_STCLASS;
+                       }
+                       if (!scan)              /* It was not CURLYX, but CURLY. */
+                           scan = next;
+                       if ( /* ? quantifier ok, except for (?{ ... }) */
+                               (next_is_eval || !(mincount == 0 && maxcount == 1))
+                               && (minnext == 0) && (deltanext == 0)
+                               && data && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
+                               && maxcount <= REG_INFTY/3 /* Complement check for big count */
+                               && ckWARN(WARN_REGEXP))
+                       {
+                           vWARN(RExC_parse,
+                                   "Quantifier unexpected on zero-length expression");
+                       }
 
-               min += minnext * mincount;
-               is_inf_internal |= ((maxcount == REG_INFTY
-                                    && (minnext + deltanext) > 0)
-                                   || deltanext == I32_MAX);
-               is_inf |= is_inf_internal;
-               delta += (minnext + deltanext) * maxcount - minnext * mincount;
-
-               /* Try powerful optimization CURLYX => CURLYN. */
-               if (  OP(oscan) == CURLYX && data
-                     && data->flags & SF_IN_PAR
-                     && !(data->flags & SF_HAS_EVAL)
-                     && !deltanext && minnext == 1 ) {
-                   /* Try to optimize to CURLYN.  */
-                   regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
-                   regnode * const nxt1 = nxt;
+                       min += minnext * mincount;
+                       is_inf_internal |= ((maxcount == REG_INFTY
+                                   && (minnext + deltanext) > 0)
+                               || deltanext == I32_MAX);
+                       is_inf |= is_inf_internal;
+                       delta += (minnext + deltanext) * maxcount - minnext * mincount;
+
+                       /* Try powerful optimization CURLYX => CURLYN. */
+                       if (  OP(oscan) == CURLYX && data
+                               && data->flags & SF_IN_PAR
+                               && !(data->flags & SF_HAS_EVAL)
+                               && !deltanext && minnext == 1 ) {
+                           /* Try to optimize to CURLYN.  */
+                           regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
+                           regnode * const nxt1 = nxt;
 #ifdef DEBUGGING
-                   regnode *nxt2;
+                           regnode *nxt2;
 #endif
 
-                   /* Skip open. */
-                   nxt = regnext(nxt);
-                   if (!strchr((const char*)PL_simple,OP(nxt))
-                       && !(PL_regkind[OP(nxt)] == EXACT
-                            && STR_LEN(nxt) == 1))
-                       goto nogo;
+                           /* Skip open. */
+                           nxt = regnext(nxt);
+                           if (!strchr((const char*)PL_simple,OP(nxt))
+                                   && !(PL_regkind[OP(nxt)] == EXACT
+                                       && STR_LEN(nxt) == 1))
+                               goto nogo;
 #ifdef DEBUGGING
-                   nxt2 = nxt;
+                           nxt2 = nxt;
 #endif
-                   nxt = regnext(nxt);
-                   if (OP(nxt) != CLOSE)
-                       goto nogo;
-                   /* Now we know that nxt2 is the only contents: */
-                   oscan->flags = (U8)ARG(nxt);
-                   OP(oscan) = CURLYN;
-                   OP(nxt1) = NOTHING; /* was OPEN. */
+                           nxt = regnext(nxt);
+                           if (OP(nxt) != CLOSE)
+                               goto nogo;
+                           if (RExC_open_parens) {
+                               RExC_open_parens[ARG(nxt1)-1]=oscan; /*open->CURLYM*/
+                               RExC_close_parens[ARG(nxt1)-1]=nxt+2; /*close->while*/
+                           }
+                           /* Now we know that nxt2 is the only contents: */
+                           oscan->flags = (U8)ARG(nxt);
+                           OP(oscan) = CURLYN;
+                           OP(nxt1) = NOTHING; /* was OPEN. */
+
 #ifdef DEBUGGING
-                   OP(nxt1 + 1) = OPTIMIZED; /* was count. */
-                   NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
-                   NEXT_OFF(nxt2) = 0; /* just for consistancy with CURLY. */
-                   OP(nxt) = OPTIMIZED;        /* was CLOSE. */
-                   OP(nxt + 1) = OPTIMIZED; /* was count. */
-                   NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
+                           OP(nxt1 + 1) = OPTIMIZED; /* was count. */
+                           NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
+                           NEXT_OFF(nxt2) = 0; /* just for consistancy with CURLY. */
+                           OP(nxt) = OPTIMIZED;        /* was CLOSE. */
+                           OP(nxt + 1) = OPTIMIZED; /* was count. */
+                           NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
 #endif
-               }
-             nogo:
-
-               /* Try optimization CURLYX => CURLYM. */
-               if (  OP(oscan) == CURLYX && data
-                     && !(data->flags & SF_HAS_PAR)
-                     && !(data->flags & SF_HAS_EVAL)
-                     && !deltanext     /* atom is fixed width */
-                     && minnext != 0   /* CURLYM can't handle zero width */
-               ) {
-                   /* XXXX How to optimize if data == 0? */
-                   /* Optimize to a simpler form.  */
-                   regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
-                   regnode *nxt2;
-
-                   OP(oscan) = CURLYM;
-                   while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
-                           && (OP(nxt2) != WHILEM))
-                       nxt = nxt2;
-                   OP(nxt2)  = SUCCEED; /* Whas WHILEM */
-                   /* Need to optimize away parenths. */
-                   if (data->flags & SF_IN_PAR) {
-                       /* Set the parenth number.  */
-                       regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
-
-                       if (OP(nxt) != CLOSE)
-                           FAIL("Panic opt close");
-                       oscan->flags = (U8)ARG(nxt);
-                       OP(nxt1) = OPTIMIZED;   /* was OPEN. */
-                       OP(nxt) = OPTIMIZED;    /* was CLOSE. */
+                       }
+nogo:
+
+                       /* Try optimization CURLYX => CURLYM. */
+                       if (  OP(oscan) == CURLYX && data
+                               && !(data->flags & SF_HAS_PAR)
+                               && !(data->flags & SF_HAS_EVAL)
+                               && !deltanext   /* atom is fixed width */
+                               && minnext != 0 /* CURLYM can't handle zero width */
+                          ) {
+                           /* XXXX How to optimize if data == 0? */
+                           /* Optimize to a simpler form.  */
+                           regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
+                           regnode *nxt2;
+
+                           OP(oscan) = CURLYM;
+                           while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
+                                   && (OP(nxt2) != WHILEM))
+                               nxt = nxt2;
+                           OP(nxt2)  = SUCCEED; /* Whas WHILEM */
+                           /* Need to optimize away parenths. */
+                           if (data->flags & SF_IN_PAR) {
+                               /* Set the parenth number.  */
+                               regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
+
+                               if (OP(nxt) != CLOSE)
+                                   FAIL("Panic opt close");
+                               oscan->flags = (U8)ARG(nxt);
+                               if (RExC_open_parens) {
+                                   RExC_open_parens[ARG(nxt1)-1]=oscan; /*open->CURLYM*/
+                                   RExC_close_parens[ARG(nxt1)-1]=nxt2+1; /*close->NOTHING*/
+                               }
+                               OP(nxt1) = OPTIMIZED;   /* was OPEN. */
+                               OP(nxt) = OPTIMIZED;    /* was CLOSE. */
+
 #ifdef DEBUGGING
-                       OP(nxt1 + 1) = OPTIMIZED; /* was count. */
-                       OP(nxt + 1) = OPTIMIZED; /* was count. */
-                       NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
-                       NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
+                               OP(nxt1 + 1) = OPTIMIZED; /* was count. */
+                               OP(nxt + 1) = OPTIMIZED; /* was count. */
+                               NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
+                               NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
 #endif
 #if 0
-                       while ( nxt1 && (OP(nxt1) != WHILEM)) {
-                           regnode *nnxt = regnext(nxt1);
-                       
-                           if (nnxt == nxt) {
-                               if (reg_off_by_arg[OP(nxt1)])
-                                   ARG_SET(nxt1, nxt2 - nxt1);
-                               else if (nxt2 - nxt1 < U16_MAX)
-                                   NEXT_OFF(nxt1) = nxt2 - nxt1;
-                               else
-                                   OP(nxt) = NOTHING;  /* Cannot beautify */
+                               while ( nxt1 && (OP(nxt1) != WHILEM)) {
+                                   regnode *nnxt = regnext(nxt1);
+
+                                   if (nnxt == nxt) {
+                                       if (reg_off_by_arg[OP(nxt1)])
+                                           ARG_SET(nxt1, nxt2 - nxt1);
+                                       else if (nxt2 - nxt1 < U16_MAX)
+                                           NEXT_OFF(nxt1) = nxt2 - nxt1;
+                                       else
+                                           OP(nxt) = NOTHING;  /* Cannot beautify */
+                                   }
+                                   nxt1 = nnxt;
+                               }
+#endif
+                               /* Optimize again: */
+                               study_chunk(pRExC_state, &nxt1, minlenp, &deltanext, nxt,
+                                       NULL, stopparen, recursed, NULL, 0,depth+1);
                            }
-                           nxt1 = nnxt;
+                           else
+                               oscan->flags = 0;
                        }
-#endif
-                       /* Optimize again: */
-                       study_chunk(pRExC_state, &nxt1, minlenp, &deltanext, nxt,
-                                   NULL, 0,depth+1);
-                   }
-                   else
-                       oscan->flags = 0;
-               }
-               else if ((OP(oscan) == CURLYX)
-                        && (flags & SCF_WHILEM_VISITED_POS)
-                        /* See the comment on a similar expression above.
-                           However, this time it not a subexpression
-                           we care about, but the expression itself. */
-                        && (maxcount == REG_INFTY)
-                        && data && ++data->whilem_c < 16) {
-                   /* This stays as CURLYX, we can put the count/of pair. */
-                   /* Find WHILEM (as in regexec.c) */
-                   regnode *nxt = oscan + NEXT_OFF(oscan);
-
-                   if (OP(PREVOPER(nxt)) == NOTHING) /* LONGJMP */
-                       nxt += ARG(nxt);
-                   PREVOPER(nxt)->flags = (U8)(data->whilem_c
-                       | (RExC_whilem_seen << 4)); /* On WHILEM */
-               }
-               if (data && fl & (SF_HAS_PAR|SF_IN_PAR))
-                   pars++;
-               if (flags & SCF_DO_SUBSTR) {
-                   SV *last_str = NULL;
-                   int counted = mincount != 0;
+                       else if ((OP(oscan) == CURLYX)
+                               && (flags & SCF_WHILEM_VISITED_POS)
+                               /* See the comment on a similar expression above.
+                                  However, this time it not a subexpression
+                                  we care about, but the expression itself. */
+                               && (maxcount == REG_INFTY)
+                               && data && ++data->whilem_c < 16) {
+                           /* This stays as CURLYX, we can put the count/of pair. */
+                           /* Find WHILEM (as in regexec.c) */
+                           regnode *nxt = oscan + NEXT_OFF(oscan);
+
+                           if (OP(PREVOPER(nxt)) == NOTHING) /* LONGJMP */
+                               nxt += ARG(nxt);
+                           PREVOPER(nxt)->flags = (U8)(data->whilem_c
+                                   | (RExC_whilem_seen << 4)); /* On WHILEM */
+                       }
+                       if (data && fl & (SF_HAS_PAR|SF_IN_PAR))
+                           pars++;
+                       if (flags & SCF_DO_SUBSTR) {
+                           SV *last_str = NULL;
+                           int counted = mincount != 0;
 
-                   if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
+                           if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
 #if defined(SPARC64_GCC_WORKAROUND)
-                       I32 b = 0;
-                       STRLEN l = 0;
-                       const char *s = NULL;
-                       I32 old = 0;
+                               I32 b = 0;
+                               STRLEN l = 0;
+                               const char *s = NULL;
+                               I32 old = 0;
 
-                       if (pos_before >= data->last_start_min)
-                           b = pos_before;
-                       else
-                           b = data->last_start_min;
+                               if (pos_before >= data->last_start_min)
+                                   b = pos_before;
+                               else
+                                   b = data->last_start_min;
 
-                       l = 0;
-                       s = SvPV_const(data->last_found, l);
-                       old = b - data->last_start_min;
+                               l = 0;
+                               s = SvPV_const(data->last_found, l);
+                               old = b - data->last_start_min;
 
 #else
-                       I32 b = pos_before >= data->last_start_min
-                           ? pos_before : data->last_start_min;
-                       STRLEN l;
-                       const char * const s = SvPV_const(data->last_found, l);
-                       I32 old = b - data->last_start_min;
+                               I32 b = pos_before >= data->last_start_min
+                                   ? pos_before : data->last_start_min;
+                               STRLEN l;
+                               const char * const s = SvPV_const(data->last_found, l);
+                               I32 old = b - data->last_start_min;
 #endif
 
-                       if (UTF)
-                           old = utf8_hop((U8*)s, old) - (U8*)s;
-                       
-                       l -= old;
-                       /* Get the added string: */
-                       last_str = newSVpvn(s  + old, l);
-                       if (UTF)
-                           SvUTF8_on(last_str);
-                       if (deltanext == 0 && pos_before == b) {
-                           /* What was added is a constant string */
-                           if (mincount > 1) {
-                               SvGROW(last_str, (mincount * l) + 1);
-                               repeatcpy(SvPVX(last_str) + l,
-                                         SvPVX_const(last_str), l, mincount - 1);
-                               SvCUR_set(last_str, SvCUR(last_str) * mincount);
-                               /* Add additional parts. */
-                               SvCUR_set(data->last_found,
-                                         SvCUR(data->last_found) - l);
-                               sv_catsv(data->last_found, last_str);
-                               {
-                                   SV * sv = data->last_found;
-                                   MAGIC *mg =
-                                       SvUTF8(sv) && SvMAGICAL(sv) ?
+                               if (UTF)
+                                   old = utf8_hop((U8*)s, old) - (U8*)s;
+
+                               l -= old;
+                               /* Get the added string: */
+                               last_str = newSVpvn(s  + old, l);
+                               if (UTF)
+                                   SvUTF8_on(last_str);
+                               if (deltanext == 0 && pos_before == b) {
+                                   /* What was added is a constant string */
+                                   if (mincount > 1) {
+                                       SvGROW(last_str, (mincount * l) + 1);
+                                       repeatcpy(SvPVX(last_str) + l,
+                                               SvPVX_const(last_str), l, mincount - 1);
+                                       SvCUR_set(last_str, SvCUR(last_str) * mincount);
+                                       /* Add additional parts. */
+                                       SvCUR_set(data->last_found,
+                                               SvCUR(data->last_found) - l);
+                                       sv_catsv(data->last_found, last_str);
+                                       {
+                                           SV * sv = data->last_found;
+                                           MAGIC *mg =
+                                               SvUTF8(sv) && SvMAGICAL(sv) ?
+                                               mg_find(sv, PERL_MAGIC_utf8) : NULL;
+                                           if (mg && mg->mg_len >= 0)
+                                               mg->mg_len += CHR_SVLEN(last_str);
+                                       }
+                                       data->last_end += l * (mincount - 1);
+                                   }
+                               } else {
+                                   /* start offset must point into the last copy */
+                                   data->last_start_min += minnext * (mincount - 1);
+                                   data->last_start_max += is_inf ? I32_MAX
+                                       : (maxcount - 1) * (minnext + data->pos_delta);
+                               }
+                           }
+                           /* It is counted once already... */
+                           data->pos_min += minnext * (mincount - counted);
+                           data->pos_delta += - counted * deltanext +
+                               (minnext + deltanext) * maxcount - minnext * mincount;
+                           if (mincount != maxcount) {
+                               /* Cannot extend fixed substrings found inside
+                                  the group.  */
+                               scan_commit(pRExC_state,data,minlenp);
+                               if (mincount && last_str) {
+                                   SV * const sv = data->last_found;
+                                   MAGIC * const mg = SvUTF8(sv) && SvMAGICAL(sv) ?
                                        mg_find(sv, PERL_MAGIC_utf8) : NULL;
-                                   if (mg && mg->mg_len >= 0)
-                                       mg->mg_len += CHR_SVLEN(last_str);
+
+                                   if (mg)
+                                       mg->mg_len = -1;
+                                   sv_setsv(sv, last_str);
+                                   data->last_end = data->pos_min;
+                                   data->last_start_min =
+                                       data->pos_min - CHR_SVLEN(last_str);
+                                   data->last_start_max = is_inf
+                                       ? I32_MAX
+                                       : data->pos_min + data->pos_delta
+                                       - CHR_SVLEN(last_str);
                                }
-                               data->last_end += l * (mincount - 1);
+                               data->longest = &(data->longest_float);
                            }
-                       } else {
-                           /* start offset must point into the last copy */
-                           data->last_start_min += minnext * (mincount - 1);
-                           data->last_start_max += is_inf ? I32_MAX
-                               : (maxcount - 1) * (minnext + data->pos_delta);
+                           SvREFCNT_dec(last_str);
                        }
-                   }
-                   /* It is counted once already... */
-                   data->pos_min += minnext * (mincount - counted);
-                   data->pos_delta += - counted * deltanext +
-                       (minnext + deltanext) * maxcount - minnext * mincount;
-                   if (mincount != maxcount) {
-                        /* Cannot extend fixed substrings found inside
-                           the group.  */
-                       scan_commit(pRExC_state,data,minlenp);
-                       if (mincount && last_str) {
-                           SV * const sv = data->last_found;
-                           MAGIC * const mg = SvUTF8(sv) && SvMAGICAL(sv) ?
-                               mg_find(sv, PERL_MAGIC_utf8) : NULL;
-
-                           if (mg)
-                               mg->mg_len = -1;
-                           sv_setsv(sv, last_str);
-                           data->last_end = data->pos_min;
-                           data->last_start_min =
-                               data->pos_min - CHR_SVLEN(last_str);
-                           data->last_start_max = is_inf
-                               ? I32_MAX
-                               : data->pos_min + data->pos_delta
-                               - CHR_SVLEN(last_str);
+                       if (data && (fl & SF_HAS_EVAL))
+                           data->flags |= SF_HAS_EVAL;
+optimize_curly_tail:
+                       if (OP(oscan) != CURLYX) {
+                           while (PL_regkind[OP(next = regnext(oscan))] == NOTHING
+                                   && NEXT_OFF(next))
+                               NEXT_OFF(oscan) += NEXT_OFF(next);
                        }
-                       data->longest = &(data->longest_float);
-                   }
-                   SvREFCNT_dec(last_str);
-               }
-               if (data && (fl & SF_HAS_EVAL))
-                   data->flags |= SF_HAS_EVAL;
-             optimize_curly_tail:
-               if (OP(oscan) != CURLYX) {
-                   while (PL_regkind[OP(next = regnext(oscan))] == NOTHING
-                          && NEXT_OFF(next))
-                       NEXT_OFF(oscan) += NEXT_OFF(next);
+                       continue;
+                   default:                    /* REF and CLUMP only? */
+                       if (flags & SCF_DO_SUBSTR) {
+                           scan_commit(pRExC_state,data,minlenp);      /* Cannot expect anything... */
+                           data->longest = &(data->longest_float);
+                       }
+                       is_inf = is_inf_internal = 1;
+                       if (flags & SCF_DO_STCLASS_OR)
+                           cl_anything(pRExC_state, data->start_class);
+                       flags &= ~SCF_DO_STCLASS;
+                       break;
                }
-               continue;
-           default:                    /* REF and CLUMP only? */
+           }
+           else if (strchr((const char*)PL_simple,OP(scan))) {
+               int value = 0;
+
                if (flags & SCF_DO_SUBSTR) {
-                   scan_commit(pRExC_state,data,minlenp);      /* Cannot expect anything... */
-                   data->longest = &(data->longest_float);
+                   scan_commit(pRExC_state,data,minlenp);
+                   data->pos_min++;
+               }
+               min++;
+               if (flags & SCF_DO_STCLASS) {
+                   data->start_class->flags &= ~ANYOF_EOS;     /* No match on empty */
+
+                   /* Some of the logic below assumes that switching
+                      locale on will only add false positives. */
+                   switch (PL_regkind[OP(scan)]) {
+                       case SANY:
+                       default:
+do_default:
+                           /* Perl_croak(aTHX_ "panic: unexpected simple REx opcode %d", OP(scan)); */
+                           if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
+                               cl_anything(pRExC_state, data->start_class);
+                           break;
+                       case REG_ANY:
+                           if (OP(scan) == SANY)
+                               goto do_default;
+                           if (flags & SCF_DO_STCLASS_OR) { /* Everything but \n */
+                               value = (ANYOF_BITMAP_TEST(data->start_class,'\n')
+                                       || (data->start_class->flags & ANYOF_CLASS));
+                               cl_anything(pRExC_state, data->start_class);
+                           }
+                           if (flags & SCF_DO_STCLASS_AND || !value)
+                               ANYOF_BITMAP_CLEAR(data->start_class,'\n');
+                           break;
+                       case ANYOF:
+                           if (flags & SCF_DO_STCLASS_AND)
+                               cl_and(data->start_class,
+                                       (struct regnode_charclass_class*)scan);
+                           else
+                               cl_or(pRExC_state, data->start_class,
+                                       (struct regnode_charclass_class*)scan);
+                           break;
+                       case ALNUM:
+                           if (flags & SCF_DO_STCLASS_AND) {
+                               if (!(data->start_class->flags & ANYOF_LOCALE)) {
+                                   ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
+                                   for (value = 0; value < 256; value++)
+                                       if (!isALNUM(value))
+                                           ANYOF_BITMAP_CLEAR(data->start_class, value);
+                               }
+                           }
+                           else {
+                               if (data->start_class->flags & ANYOF_LOCALE)
+                                   ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
+                               else {
+                                   for (value = 0; value < 256; value++)
+                                       if (isALNUM(value))
+                                           ANYOF_BITMAP_SET(data->start_class, value);
+                               }
+                           }
+                           break;
+                       case ALNUML:
+                           if (flags & SCF_DO_STCLASS_AND) {
+                               if (data->start_class->flags & ANYOF_LOCALE)
+                                   ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
+                           }
+                           else {
+                               ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
+                               data->start_class->flags |= ANYOF_LOCALE;
+                           }
+                           break;
+                       case NALNUM:
+                           if (flags & SCF_DO_STCLASS_AND) {
+                               if (!(data->start_class->flags & ANYOF_LOCALE)) {
+                                   ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
+                                   for (value = 0; value < 256; value++)
+                                       if (isALNUM(value))
+                                           ANYOF_BITMAP_CLEAR(data->start_class, value);
+                               }
+                           }
+                           else {
+                               if (data->start_class->flags & ANYOF_LOCALE)
+                                   ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
+                               else {
+                                   for (value = 0; value < 256; value++)
+                                       if (!isALNUM(value))
+                                           ANYOF_BITMAP_SET(data->start_class, value);
+                               }
+                           }
+                           break;
+                       case NALNUML:
+                           if (flags & SCF_DO_STCLASS_AND) {
+                               if (data->start_class->flags & ANYOF_LOCALE)
+                                   ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
+                           }
+                           else {
+                               data->start_class->flags |= ANYOF_LOCALE;
+                               ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
+                           }
+                           break;
+                       case SPACE:
+                           if (flags & SCF_DO_STCLASS_AND) {
+                               if (!(data->start_class->flags & ANYOF_LOCALE)) {
+                                   ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
+                                   for (value = 0; value < 256; value++)
+                                       if (!isSPACE(value))
+                                           ANYOF_BITMAP_CLEAR(data->start_class, value);
+                               }
+                           }
+                           else {
+                               if (data->start_class->flags & ANYOF_LOCALE)
+                                   ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
+                               else {
+                                   for (value = 0; value < 256; value++)
+                                       if (isSPACE(value))
+                                           ANYOF_BITMAP_SET(data->start_class, value);
+                               }
+                           }
+                           break;
+                       case SPACEL:
+                           if (flags & SCF_DO_STCLASS_AND) {
+                               if (data->start_class->flags & ANYOF_LOCALE)
+                                   ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
+                           }
+                           else {
+                               data->start_class->flags |= ANYOF_LOCALE;
+                               ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
+                           }
+                           break;
+                       case NSPACE:
+                           if (flags & SCF_DO_STCLASS_AND) {
+                               if (!(data->start_class->flags & ANYOF_LOCALE)) {
+                                   ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
+                                   for (value = 0; value < 256; value++)
+                                       if (isSPACE(value))
+                                           ANYOF_BITMAP_CLEAR(data->start_class, value);
+                               }
+                           }
+                           else {
+                               if (data->start_class->flags & ANYOF_LOCALE)
+                                   ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
+                               else {
+                                   for (value = 0; value < 256; value++)
+                                       if (!isSPACE(value))
+                                           ANYOF_BITMAP_SET(data->start_class, value);
+                               }
+                           }
+                           break;
+                       case NSPACEL:
+                           if (flags & SCF_DO_STCLASS_AND) {
+                               if (data->start_class->flags & ANYOF_LOCALE) {
+                                   ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
+                                   for (value = 0; value < 256; value++)
+                                       if (!isSPACE(value))
+                                           ANYOF_BITMAP_CLEAR(data->start_class, value);
+                               }
+                           }
+                           else {
+                               data->start_class->flags |= ANYOF_LOCALE;
+                               ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
+                           }
+                           break;
+                       case DIGIT:
+                           if (flags & SCF_DO_STCLASS_AND) {
+                               ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NDIGIT);
+                               for (value = 0; value < 256; value++)
+                                   if (!isDIGIT(value))
+                                       ANYOF_BITMAP_CLEAR(data->start_class, value);
+                           }
+                           else {
+                               if (data->start_class->flags & ANYOF_LOCALE)
+                                   ANYOF_CLASS_SET(data->start_class,ANYOF_DIGIT);
+                               else {
+                                   for (value = 0; value < 256; value++)
+                                       if (isDIGIT(value))
+                                           ANYOF_BITMAP_SET(data->start_class, value);                 
+                               }
+                           }
+                           break;
+                       case NDIGIT:
+                           if (flags & SCF_DO_STCLASS_AND) {
+                               ANYOF_CLASS_CLEAR(data->start_class,ANYOF_DIGIT);
+                               for (value = 0; value < 256; value++)
+                                   if (isDIGIT(value))
+                                       ANYOF_BITMAP_CLEAR(data->start_class, value);
+                           }
+                           else {
+                               if (data->start_class->flags & ANYOF_LOCALE)
+                                   ANYOF_CLASS_SET(data->start_class,ANYOF_NDIGIT);
+                               else {
+                                   for (value = 0; value < 256; value++)
+                                       if (!isDIGIT(value))
+                                           ANYOF_BITMAP_SET(data->start_class, value);                 
+                               }
+                           }
+                           break;
+                   }
+                   if (flags & SCF_DO_STCLASS_OR)
+                       cl_and(data->start_class, and_withp);
+                   flags &= ~SCF_DO_STCLASS;
                }
-               is_inf = is_inf_internal = 1;
-               if (flags & SCF_DO_STCLASS_OR)
-                   cl_anything(pRExC_state, data->start_class);
-               flags &= ~SCF_DO_STCLASS;
-               break;
            }
-       }
-       else if (strchr((const char*)PL_simple,OP(scan))) {
-           int value = 0;
-
-           if (flags & SCF_DO_SUBSTR) {
-               scan_commit(pRExC_state,data,minlenp);
-               data->pos_min++;
+           else if (PL_regkind[OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
+               data->flags |= (OP(scan) == MEOL
+                       ? SF_BEFORE_MEOL
+                       : SF_BEFORE_SEOL);
            }
-           min++;
-           if (flags & SCF_DO_STCLASS) {
-               data->start_class->flags &= ~ANYOF_EOS; /* No match on empty */
+           else if (  PL_regkind[OP(scan)] == BRANCHJ
+                   /* Lookbehind, or need to calculate parens/evals/stclass: */
+                   && (scan->flags || data || (flags & SCF_DO_STCLASS))
+                   && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
+               if ( !PERL_ENABLE_POSITIVE_ASSERTION_STUDY 
+                       || OP(scan) == UNLESSM )
+               {
+                   /* Negative Lookahead/lookbehind
+                      In this case we can't do fixed string optimisation.
+                      */
 
-               /* Some of the logic below assumes that switching
-                  locale on will only add false positives. */
-               switch (PL_regkind[OP(scan)]) {
-               case SANY:
-               default:
-                 do_default:
-                   /* Perl_croak(aTHX_ "panic: unexpected simple REx opcode %d", OP(scan)); */
-                   if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
-                       cl_anything(pRExC_state, data->start_class);
-                   break;
-               case REG_ANY:
-                   if (OP(scan) == SANY)
-                       goto do_default;
-                   if (flags & SCF_DO_STCLASS_OR) { /* Everything but \n */
-                       value = (ANYOF_BITMAP_TEST(data->start_class,'\n')
-                                || (data->start_class->flags & ANYOF_CLASS));
-                       cl_anything(pRExC_state, data->start_class);
+                   I32 deltanext, minnext, fake = 0;
+                   regnode *nscan;
+                   struct regnode_charclass_class intrnl;
+                   int f = 0;
+
+                   data_fake.flags = 0;
+                   if (data) {
+                       data_fake.whilem_c = data->whilem_c;
+                       data_fake.last_closep = data->last_closep;
                    }
-                   if (flags & SCF_DO_STCLASS_AND || !value)
-                       ANYOF_BITMAP_CLEAR(data->start_class,'\n');
-                   break;
-               case ANYOF:
-                   if (flags & SCF_DO_STCLASS_AND)
-                       cl_and(data->start_class,
-                              (struct regnode_charclass_class*)scan);
                    else
-                       cl_or(pRExC_state, data->start_class,
-                             (struct regnode_charclass_class*)scan);
-                   break;
-               case ALNUM:
-                   if (flags & SCF_DO_STCLASS_AND) {
-                       if (!(data->start_class->flags & ANYOF_LOCALE)) {
-                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
-                           for (value = 0; value < 256; value++)
-                               if (!isALNUM(value))
-                                   ANYOF_BITMAP_CLEAR(data->start_class, value);
-                       }
-                   }
-                   else {
-                       if (data->start_class->flags & ANYOF_LOCALE)
-                           ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
-                       else {
-                           for (value = 0; value < 256; value++)
-                               if (isALNUM(value))
-                                   ANYOF_BITMAP_SET(data->start_class, value);                 
-                       }
-                   }
-                   break;
-               case ALNUML:
-                   if (flags & SCF_DO_STCLASS_AND) {
-                       if (data->start_class->flags & ANYOF_LOCALE)
-                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
-                   }
-                   else {
-                       ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
-                       data->start_class->flags |= ANYOF_LOCALE;
-                   }
-                   break;
-               case NALNUM:
-                   if (flags & SCF_DO_STCLASS_AND) {
-                       if (!(data->start_class->flags & ANYOF_LOCALE)) {
-                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
-                           for (value = 0; value < 256; value++)
-                               if (isALNUM(value))
-                                   ANYOF_BITMAP_CLEAR(data->start_class, value);
-                       }
-                   }
-                   else {
-                       if (data->start_class->flags & ANYOF_LOCALE)
-                           ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
-                       else {
-                           for (value = 0; value < 256; value++)
-                               if (!isALNUM(value))
-                                   ANYOF_BITMAP_SET(data->start_class, value);                 
-                       }
-                   }
-                   break;
-               case NALNUML:
-                   if (flags & SCF_DO_STCLASS_AND) {
-                       if (data->start_class->flags & ANYOF_LOCALE)
-                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
-                   }
-                   else {
-                       data->start_class->flags |= ANYOF_LOCALE;
-                       ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
+                       data_fake.last_closep = &fake;
+                   if ( flags & SCF_DO_STCLASS && !scan->flags
+                           && OP(scan) == IFMATCH ) { /* Lookahead */
+                       cl_init(pRExC_state, &intrnl);
+                       data_fake.start_class = &intrnl;
+                       f |= SCF_DO_STCLASS_AND;
                    }
-                   break;
-               case SPACE:
-                   if (flags & SCF_DO_STCLASS_AND) {
-                       if (!(data->start_class->flags & ANYOF_LOCALE)) {
-                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
-                           for (value = 0; value < 256; value++)
-                               if (!isSPACE(value))
-                                   ANYOF_BITMAP_CLEAR(data->start_class, value);
+                   if (flags & SCF_WHILEM_VISITED_POS)
+                       f |= SCF_WHILEM_VISITED_POS;
+                   next = regnext(scan);
+                   nscan = NEXTOPER(NEXTOPER(scan));
+                   minnext = study_chunk(pRExC_state, &nscan, minlenp, &deltanext, 
+                           last, &data_fake, stopparen, recursed, NULL, f, depth+1);
+                   if (scan->flags) {
+                       if (deltanext) {
+                           vFAIL("Variable length lookbehind not implemented");
                        }
-                   }
-                   else {
-                       if (data->start_class->flags & ANYOF_LOCALE)
-                           ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
-                       else {
-                           for (value = 0; value < 256; value++)
-                               if (isSPACE(value))
-                                   ANYOF_BITMAP_SET(data->start_class, value);                 
+                       else if (minnext > (I32)U8_MAX) {
+                           vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
                        }
+                       scan->flags = (U8)minnext;
                    }
-                   break;
-               case SPACEL:
-                   if (flags & SCF_DO_STCLASS_AND) {
-                       if (data->start_class->flags & ANYOF_LOCALE)
-                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
+                   if (data) {
+                       if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
+                           pars++;
+                       if (data_fake.flags & SF_HAS_EVAL)
+                           data->flags |= SF_HAS_EVAL;
+                       data->whilem_c = data_fake.whilem_c;
                    }
-                   else {
-                       data->start_class->flags |= ANYOF_LOCALE;
-                       ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
+                   if (f & SCF_DO_STCLASS_AND) {
+                       const int was = (data->start_class->flags & ANYOF_EOS);
+
+                       cl_and(data->start_class, &intrnl);
+                       if (was)
+                           data->start_class->flags |= ANYOF_EOS;
                    }
-                   break;
-               case NSPACE:
-                   if (flags & SCF_DO_STCLASS_AND) {
-                       if (!(data->start_class->flags & ANYOF_LOCALE)) {
-                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
-                           for (value = 0; value < 256; value++)
-                               if (isSPACE(value))
-                                   ANYOF_BITMAP_CLEAR(data->start_class, value);
+               }
+#if PERL_ENABLE_POSITIVE_ASSERTION_STUDY
+               else {
+                   /* Positive Lookahead/lookbehind
+                      In this case we can do fixed string optimisation,
+                      but we must be careful about it. Note in the case of
+                      lookbehind the positions will be offset by the minimum
+                      length of the pattern, something we won't know about
+                      until after the recurse.
+                      */
+                   I32 deltanext, fake = 0;
+                   regnode *nscan;
+                   struct regnode_charclass_class intrnl;
+                   int f = 0;
+                   /* We use SAVEFREEPV so that when the full compile 
+                      is finished perl will clean up the allocated 
+                      minlens when its all done. This was we don't
+                      have to worry about freeing them when we know
+                      they wont be used, which would be a pain.
+                      */
+                   I32 *minnextp;
+                   Newx( minnextp, 1, I32 );
+                   SAVEFREEPV(minnextp);
+
+                   if (data) {
+                       StructCopy(data, &data_fake, scan_data_t);
+                       if ((flags & SCF_DO_SUBSTR) && data->last_found) {
+                           f |= SCF_DO_SUBSTR;
+                           if (scan->flags) 
+                               scan_commit(pRExC_state, &data_fake,minlenp);
+                           data_fake.last_found=newSVsv(data->last_found);
                        }
                    }
-                   else {
-                       if (data->start_class->flags & ANYOF_LOCALE)
-                           ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
-                       else {
-                           for (value = 0; value < 256; value++)
-                               if (!isSPACE(value))
-                                   ANYOF_BITMAP_SET(data->start_class, value);                 
-                       }
+                   else
+                       data_fake.last_closep = &fake;
+                   data_fake.flags = 0;
+                   if (is_inf)
+                       data_fake.flags |= SF_IS_INF;
+                   if ( flags & SCF_DO_STCLASS && !scan->flags
+                           && OP(scan) == IFMATCH ) { /* Lookahead */
+                       cl_init(pRExC_state, &intrnl);
+                       data_fake.start_class = &intrnl;
+                       f |= SCF_DO_STCLASS_AND;
                    }
-                   break;
-               case NSPACEL:
-                   if (flags & SCF_DO_STCLASS_AND) {
-                       if (data->start_class->flags & ANYOF_LOCALE) {
-                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
-                           for (value = 0; value < 256; value++)
-                               if (!isSPACE(value))
-                                   ANYOF_BITMAP_CLEAR(data->start_class, value);
+                   if (flags & SCF_WHILEM_VISITED_POS)
+                       f |= SCF_WHILEM_VISITED_POS;
+                   next = regnext(scan);
+                   nscan = NEXTOPER(NEXTOPER(scan));
+
+                   *minnextp = study_chunk(pRExC_state, &nscan, minnextp, &deltanext, 
+                           last, &data_fake, stopparen, recursed, NULL, f,depth+1);
+                   if (scan->flags) {
+                       if (deltanext) {
+                           vFAIL("Variable length lookbehind not implemented");
                        }
-                   }
-                   else {
-                       data->start_class->flags |= ANYOF_LOCALE;
-                       ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
-                   }
-                   break;
-               case DIGIT:
-                   if (flags & SCF_DO_STCLASS_AND) {
-                       ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NDIGIT);
-                       for (value = 0; value < 256; value++)
-                           if (!isDIGIT(value))
-                               ANYOF_BITMAP_CLEAR(data->start_class, value);
-                   }
-                   else {
-                       if (data->start_class->flags & ANYOF_LOCALE)
-                           ANYOF_CLASS_SET(data->start_class,ANYOF_DIGIT);
-                       else {
-                           for (value = 0; value < 256; value++)
-                               if (isDIGIT(value))
-                                   ANYOF_BITMAP_SET(data->start_class, value);                 
+                       else if (*minnextp > (I32)U8_MAX) {
+                           vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
                        }
+                       scan->flags = (U8)*minnextp;
                    }
-                   break;
-               case NDIGIT:
-                   if (flags & SCF_DO_STCLASS_AND) {
-                       ANYOF_CLASS_CLEAR(data->start_class,ANYOF_DIGIT);
-                       for (value = 0; value < 256; value++)
-                           if (isDIGIT(value))
-                               ANYOF_BITMAP_CLEAR(data->start_class, value);
+
+                   *minnextp += min;
+
+                   if (f & SCF_DO_STCLASS_AND) {
+                       const int was = (data->start_class->flags & ANYOF_EOS);
+
+                       cl_and(data->start_class, &intrnl);
+                       if (was)
+                           data->start_class->flags |= ANYOF_EOS;
                    }
-                   else {
-                       if (data->start_class->flags & ANYOF_LOCALE)
-                           ANYOF_CLASS_SET(data->start_class,ANYOF_NDIGIT);
-                       else {
-                           for (value = 0; value < 256; value++)
-                               if (!isDIGIT(value))
-                                   ANYOF_BITMAP_SET(data->start_class, value);                 
+                   if (data) {
+                       if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
+                           pars++;
+                       if (data_fake.flags & SF_HAS_EVAL)
+                           data->flags |= SF_HAS_EVAL;
+                       data->whilem_c = data_fake.whilem_c;
+                       if ((flags & SCF_DO_SUBSTR) && data_fake.last_found) {
+                           if (RExC_rx->minlen<*minnextp)
+                               RExC_rx->minlen=*minnextp;
+                           scan_commit(pRExC_state, &data_fake, minnextp);
+                           SvREFCNT_dec(data_fake.last_found);
+
+                           if ( data_fake.minlen_fixed != minlenp ) 
+                           {
+                               data->offset_fixed= data_fake.offset_fixed;
+                               data->minlen_fixed= data_fake.minlen_fixed;
+                               data->lookbehind_fixed+= scan->flags;
+                           }
+                           if ( data_fake.minlen_float != minlenp )
+                           {
+                               data->minlen_float= data_fake.minlen_float;
+                               data->offset_float_min=data_fake.offset_float_min;
+                               data->offset_float_max=data_fake.offset_float_max;
+                               data->lookbehind_float+= scan->flags;
+                           }
                        }
                    }
-                   break;
-               }
-               if (flags & SCF_DO_STCLASS_OR)
-                   cl_and(data->start_class, &and_with);
-               flags &= ~SCF_DO_STCLASS;
-           }
-       }
-       else if (PL_regkind[OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
-           data->flags |= (OP(scan) == MEOL
-                           ? SF_BEFORE_MEOL
-                           : SF_BEFORE_SEOL);
-       }
-       else if (  PL_regkind[OP(scan)] == BRANCHJ
-                /* Lookbehind, or need to calculate parens/evals/stclass: */
-                  && (scan->flags || data || (flags & SCF_DO_STCLASS))
-                  && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
-            if ( !PERL_ENABLE_POSITIVE_ASSERTION_STUDY 
-                || OP(scan) == UNLESSM )
-            {
-                /* Negative Lookahead/lookbehind
-                   In this case we can't do fixed string optimisation.
-                */
 
-                I32 deltanext, minnext, fake = 0;
-                regnode *nscan;
-                struct regnode_charclass_class intrnl;
-                int f = 0;
 
-                data_fake.flags = 0;
-                if (data) {
-                    data_fake.whilem_c = data->whilem_c;
-                    data_fake.last_closep = data->last_closep;
-               }
-                else
-                    data_fake.last_closep = &fake;
-                if ( flags & SCF_DO_STCLASS && !scan->flags
-                     && OP(scan) == IFMATCH ) { /* Lookahead */
-                    cl_init(pRExC_state, &intrnl);
-                    data_fake.start_class = &intrnl;
-                    f |= SCF_DO_STCLASS_AND;
                }
-                if (flags & SCF_WHILEM_VISITED_POS)
-                    f |= SCF_WHILEM_VISITED_POS;
-                next = regnext(scan);
-                nscan = NEXTOPER(NEXTOPER(scan));
-                minnext = study_chunk(pRExC_state, &nscan, minlenp, &deltanext, last, &data_fake, f,depth+1);
-                if (scan->flags) {
-                    if (deltanext) {
-                        vFAIL("Variable length lookbehind not implemented");
-                    }
-                    else if (minnext > (I32)U8_MAX) {
-                        vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
-                    }
-                    scan->flags = (U8)minnext;
-                }
-                if (data) {
-                    if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
-                        pars++;
-                    if (data_fake.flags & SF_HAS_EVAL)
-                        data->flags |= SF_HAS_EVAL;
-                    data->whilem_c = data_fake.whilem_c;
-                }
-                if (f & SCF_DO_STCLASS_AND) {
-                    const int was = (data->start_class->flags & ANYOF_EOS);
-
-                    cl_and(data->start_class, &intrnl);
-                    if (was)
-                        data->start_class->flags |= ANYOF_EOS;
-                }
+#endif
            }
-#if PERL_ENABLE_POSITIVE_ASSERTION_STUDY
-            else {
-                /* Positive Lookahead/lookbehind
-                   In this case we can do fixed string optimisation,
-                   but we must be careful about it. Note in the case of
-                   lookbehind the positions will be offset by the minimum
-                   length of the pattern, something we won't know about
-                   until after the recurse.
-                */
-                I32 deltanext, fake = 0;
-                regnode *nscan;
-                struct regnode_charclass_class intrnl;
-                int f = 0;
-                /* We use SAVEFREEPV so that when the full compile 
-                    is finished perl will clean up the allocated 
-                    minlens when its all done. This was we don't
-                    have to worry about freeing them when we know
-                    they wont be used, which would be a pain.
-                 */
-                I32 *minnextp;
-                Newx( minnextp, 1, I32 );
-                SAVEFREEPV(minnextp);
-
-                if (data) {
-                    StructCopy(data, &data_fake, scan_data_t);
-                    if ((flags & SCF_DO_SUBSTR) && data->last_found) {
-                        f |= SCF_DO_SUBSTR;
-                        if (scan->flags) 
-                            scan_commit(pRExC_state, &data_fake,minlenp);
-                        data_fake.last_found=newSVsv(data->last_found);
-                    }
-                }
-                else
-                    data_fake.last_closep = &fake;
-                data_fake.flags = 0;
-                if (is_inf)
-                   data_fake.flags |= SF_IS_INF;
-                if ( flags & SCF_DO_STCLASS && !scan->flags
-                     && OP(scan) == IFMATCH ) { /* Lookahead */
-                    cl_init(pRExC_state, &intrnl);
-                    data_fake.start_class = &intrnl;
-                    f |= SCF_DO_STCLASS_AND;
-                }
-                if (flags & SCF_WHILEM_VISITED_POS)
-                    f |= SCF_WHILEM_VISITED_POS;
-                next = regnext(scan);
-                nscan = NEXTOPER(NEXTOPER(scan));
-                
-                *minnextp = study_chunk(pRExC_state, &nscan, minnextp, &deltanext, last, &data_fake, f,depth+1);
-                if (scan->flags) {
-                    if (deltanext) {
-                        vFAIL("Variable length lookbehind not implemented");
-                    }
-                    else if (*minnextp > (I32)U8_MAX) {
-                        vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
-                    }
-                    scan->flags = (U8)*minnextp;
-                }
-                
-                *minnextp += min;
-                
-                    
-                if (f & SCF_DO_STCLASS_AND) {
-                    const int was = (data->start_class->flags & ANYOF_EOS);
-
-                    cl_and(data->start_class, &intrnl);
-                    if (was)
-                        data->start_class->flags |= ANYOF_EOS;
-                }                
-                if (data) {
-                    if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
-                        pars++;
-                    if (data_fake.flags & SF_HAS_EVAL)
-                        data->flags |= SF_HAS_EVAL;
-                    data->whilem_c = data_fake.whilem_c;
-                    if ((flags & SCF_DO_SUBSTR) && data_fake.last_found) {
-                        if (RExC_rx->minlen<*minnextp)
-                            RExC_rx->minlen=*minnextp;
-                        scan_commit(pRExC_state, &data_fake, minnextp);
-                        SvREFCNT_dec(data_fake.last_found);
-                        
-                        if ( data_fake.minlen_fixed != minlenp ) 
-                        {
-                            data->offset_fixed= data_fake.offset_fixed;
-                            data->minlen_fixed= data_fake.minlen_fixed;
-                            data->lookbehind_fixed+= scan->flags;
-                        }
-                        if ( data_fake.minlen_float != minlenp )
-                        {
-                            data->minlen_float= data_fake.minlen_float;
-                            data->offset_float_min=data_fake.offset_float_min;
-                            data->offset_float_max=data_fake.offset_float_max;
-                            data->lookbehind_float+= scan->flags;
-                        }
-                    }
-                }
-
-
+           else if (OP(scan) == OPEN) {
+               if (stopparen != (I32)ARG(scan))
+                   pars++;
            }
-#endif
-       }
-       else if (OP(scan) == OPEN) {
-           pars++;
-       }
-       else if (OP(scan) == CLOSE) {
-           if ((I32)ARG(scan) == is_par) {
-               next = regnext(scan);
+           else if (OP(scan) == CLOSE) {
+               if (stopparen == (I32)ARG(scan)) {
+                   break;
+               }
+               if ((I32)ARG(scan) == is_par) {
+                   next = regnext(scan);
 
-               if ( next && (OP(next) != WHILEM) && next < last)
-                   is_par = 0;         /* Disable optimization */
+                   if ( next && (OP(next) != WHILEM) && next < last)
+                       is_par = 0;             /* Disable optimization */
+               }
+               if (data)
+                   *(data->last_closep) = ARG(scan);
            }
-           if (data)
-               *(data->last_closep) = ARG(scan);
-       }
-       else if (OP(scan) == EVAL) {
+           else if (OP(scan) == EVAL) {
                if (data)
                    data->flags |= SF_HAS_EVAL;
-       }
-       else if ( (OP(scan) == LOGICAL && scan->flags == 2) /* Embedded follows */
-                 || OP(scan)==RECURSE)  /* recursion */
-       { 
-               if (OP(scan)==RECURSE) {
-                   ARG2L_SET( scan, RExC_parens[ARG(scan)-1] - scan );     
-               }    
+           }
+           else if ( PL_regkind[OP(scan)] == ENDLIKE ) {
+               if (flags & SCF_DO_SUBSTR) {
+                   scan_commit(pRExC_state,data,minlenp);
+                   flags &= ~SCF_DO_SUBSTR;
+               }
+               if (data && OP(scan)==ACCEPT) {
+                   data->flags |= SCF_SEEN_ACCEPT;
+                   if (stopmin > min)
+                       stopmin = min;
+               }
+           }
+           else if (OP(scan) == LOGICAL && scan->flags == 2) /* Embedded follows */
+           {
                if (flags & SCF_DO_SUBSTR) {
                    scan_commit(pRExC_state,data,minlenp);
                    data->longest = &(data->longest_float);
@@ -3463,141 +3632,156 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
                    cl_anything(pRExC_state, data->start_class);
                flags &= ~SCF_DO_STCLASS;
-       }
+           }
 #ifdef TRIE_STUDY_OPT
-#ifdef FULL_TRIE_STUDY        
-        else if (PL_regkind[OP(scan)] == TRIE) {
-            /* NOTE - There is similar code to this block above for handling
-               BRANCH nodes on the initial study.  If you change stuff here 
-               check there too. */
-            regnode *tail= regnext(scan);
-            reg_trie_data *trie = (reg_trie_data*)RExC_rx->data->data[ ARG(scan) ];
-            I32 max1 = 0, min1 = I32_MAX;
-            struct regnode_charclass_class accum;
-
-            if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
-                scan_commit(pRExC_state, data,minlenp); /* Cannot merge strings after this. */
-            if (flags & SCF_DO_STCLASS)
-                cl_init_zero(pRExC_state, &accum);
-                
-            if (!trie->jump) {
-                min1= trie->minlen;
-                max1= trie->maxlen;
-            } else {
-                const regnode *nextbranch= NULL;
-                U32 word;
-                
-                for ( word=1 ; word <= trie->wordcount ; word++) 
-                {
-                    I32 deltanext=0, minnext=0, f = 0, fake;
-                    struct regnode_charclass_class this_class;
-                    
-                    data_fake.flags = 0;
-                    if (data) {
-                        data_fake.whilem_c = data->whilem_c;
-                        data_fake.last_closep = data->last_closep;
-                    }
-                    else
-                        data_fake.last_closep = &fake;
-                        
-                    if (flags & SCF_DO_STCLASS) {
-                        cl_init(pRExC_state, &this_class);
-                        data_fake.start_class = &this_class;
-                        f = SCF_DO_STCLASS_AND;
-                    }
-                    if (flags & SCF_WHILEM_VISITED_POS)
-                        f |= SCF_WHILEM_VISITED_POS;
-    
-                    if (trie->jump[word]) {
-                        if (!nextbranch)
-                            nextbranch = tail - trie->jump[0];
-                        scan= tail - trie->jump[word];
-                        /* We go from the jump point to the branch that follows
-                           it. Note this means we need the vestigal unused branches
-                           even though they arent otherwise used.
-                         */
-                        minnext = study_chunk(pRExC_state, &scan, minlenp, &deltanext,
-                                              (regnode *)nextbranch, &data_fake, f,depth+1);
-                    }
-                    if (nextbranch && PL_regkind[OP(nextbranch)]==BRANCH)
-                        nextbranch= regnext((regnode*)nextbranch);
-                    
-                    if (min1 > (I32)(minnext + trie->minlen))
-                        min1 = minnext + trie->minlen;
-                    if (max1 < (I32)(minnext + deltanext + trie->maxlen))
-                        max1 = minnext + deltanext + trie->maxlen;
-                    if (deltanext == I32_MAX)
-                        is_inf = is_inf_internal = 1;
-                    
-                    if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
-                        pars++;
-                    
-                    if (data) {
-                        if (data_fake.flags & SF_HAS_EVAL)
-                            data->flags |= SF_HAS_EVAL;
-                        data->whilem_c = data_fake.whilem_c;
-                    }
-                    if (flags & SCF_DO_STCLASS)
-                        cl_or(pRExC_state, &accum, &this_class);
-                }
-            }
-            if (flags & SCF_DO_SUBSTR) {
-                data->pos_min += min1;
-                data->pos_delta += max1 - min1;
-                if (max1 != min1 || is_inf)
-                    data->longest = &(data->longest_float);
-            }
-            min += min1;
-            delta += max1 - min1;
-            if (flags & SCF_DO_STCLASS_OR) {
-                cl_or(pRExC_state, data->start_class, &accum);
-                if (min1) {
-                    cl_and(data->start_class, &and_with);
-                    flags &= ~SCF_DO_STCLASS;
-                }
-            }
-            else if (flags & SCF_DO_STCLASS_AND) {
-                if (min1) {
-                    cl_and(data->start_class, &accum);
-                    flags &= ~SCF_DO_STCLASS;
-                }
-                else {
-                    /* Switch to OR mode: cache the old value of
-                     * data->start_class */
-                    StructCopy(data->start_class, &and_with,
-                               struct regnode_charclass_class);
-                    flags &= ~SCF_DO_STCLASS_AND;
-                    StructCopy(&accum, data->start_class,
-                               struct regnode_charclass_class);
-                    flags |= SCF_DO_STCLASS_OR;
-                    data->start_class->flags |= ANYOF_EOS;
-                }
-            }
-            scan= tail;
-            continue;
-        }
+#ifdef FULL_TRIE_STUDY
+           else if (PL_regkind[OP(scan)] == TRIE) {
+               /* NOTE - There is similar code to this block above for handling
+                  BRANCH nodes on the initial study.  If you change stuff here
+                  check there too. */
+               regnode *trie_node= scan;
+               regnode *tail= regnext(scan);
+               reg_trie_data *trie = (reg_trie_data*)RExC_rx->data->data[ ARG(scan) ];
+               I32 max1 = 0, min1 = I32_MAX;
+               struct regnode_charclass_class accum;
+
+               if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
+                   scan_commit(pRExC_state, data,minlenp); /* Cannot merge strings after this. */
+               if (flags & SCF_DO_STCLASS)
+                   cl_init_zero(pRExC_state, &accum);
+
+               if (!trie->jump) {
+                   min1= trie->minlen;
+                   max1= trie->maxlen;
+               } else {
+                   const regnode *nextbranch= NULL;
+                   U32 word;
+
+                   for ( word=1 ; word <= trie->wordcount ; word++) 
+                   {
+                       I32 deltanext=0, minnext=0, f = 0, fake;
+                       struct regnode_charclass_class this_class;
+
+                       data_fake.flags = 0;
+                       if (data) {
+                           data_fake.whilem_c = data->whilem_c;
+                           data_fake.last_closep = data->last_closep;
+                       }
+                       else
+                           data_fake.last_closep = &fake;
+
+                       if (flags & SCF_DO_STCLASS) {
+                           cl_init(pRExC_state, &this_class);
+                           data_fake.start_class = &this_class;
+                           f = SCF_DO_STCLASS_AND;
+                       }
+                       if (flags & SCF_WHILEM_VISITED_POS)
+                           f |= SCF_WHILEM_VISITED_POS;
+
+                       if (trie->jump[word]) {
+                           if (!nextbranch)
+                               nextbranch = trie_node + trie->jump[0];
+                           scan= trie_node + trie->jump[word];
+                           /* We go from the jump point to the branch that follows
+                              it. Note this means we need the vestigal unused branches
+                              even though they arent otherwise used.
+                              */
+                           minnext = study_chunk(pRExC_state, &scan, minlenp, 
+                                   &deltanext, (regnode *)nextbranch, &data_fake, 
+                                   stopparen, recursed, NULL, f,depth+1);
+                       }
+                       if (nextbranch && PL_regkind[OP(nextbranch)]==BRANCH)
+                           nextbranch= regnext((regnode*)nextbranch);
+
+                       if (min1 > (I32)(minnext + trie->minlen))
+                           min1 = minnext + trie->minlen;
+                       if (max1 < (I32)(minnext + deltanext + trie->maxlen))
+                           max1 = minnext + deltanext + trie->maxlen;
+                       if (deltanext == I32_MAX)
+                           is_inf = is_inf_internal = 1;
+
+                       if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
+                           pars++;
+                       if (data_fake.flags & SCF_SEEN_ACCEPT) {
+                           if ( stopmin > min + min1) 
+                               stopmin = min + min1;
+                           flags &= ~SCF_DO_SUBSTR;
+                           if (data)
+                               data->flags |= SCF_SEEN_ACCEPT;
+                       }
+                       if (data) {
+                           if (data_fake.flags & SF_HAS_EVAL)
+                               data->flags |= SF_HAS_EVAL;
+                           data->whilem_c = data_fake.whilem_c;
+                       }
+                       if (flags & SCF_DO_STCLASS)
+                           cl_or(pRExC_state, &accum, &this_class);
+                   }
+               }
+               if (flags & SCF_DO_SUBSTR) {
+                   data->pos_min += min1;
+                   data->pos_delta += max1 - min1;
+                   if (max1 != min1 || is_inf)
+                       data->longest = &(data->longest_float);
+               }
+               min += min1;
+               delta += max1 - min1;
+               if (flags & SCF_DO_STCLASS_OR) {
+                   cl_or(pRExC_state, data->start_class, &accum);
+                   if (min1) {
+                       cl_and(data->start_class, and_withp);
+                       flags &= ~SCF_DO_STCLASS;
+                   }
+               }
+               else if (flags & SCF_DO_STCLASS_AND) {
+                   if (min1) {
+                       cl_and(data->start_class, &accum);
+                       flags &= ~SCF_DO_STCLASS;
+                   }
+                   else {
+                       /* Switch to OR mode: cache the old value of
+                        * data->start_class */
+                       INIT_AND_WITHP;
+                       StructCopy(data->start_class, and_withp,
+                               struct regnode_charclass_class);
+                       flags &= ~SCF_DO_STCLASS_AND;
+                       StructCopy(&accum, data->start_class,
+                               struct regnode_charclass_class);
+                       flags |= SCF_DO_STCLASS_OR;
+                       data->start_class->flags |= ANYOF_EOS;
+                   }
+               }
+               scan= tail;
+               continue;
+           }
 #else
-       else if (PL_regkind[OP(scan)] == TRIE) {
-           reg_trie_data *trie = (reg_trie_data*)RExC_rx->data->data[ ARG(scan) ];
-           U8*bang=NULL;
-           
-           min += trie->minlen;
-           delta += (trie->maxlen - trie->minlen);
-           flags &= ~SCF_DO_STCLASS; /* xxx */
-            if (flags & SCF_DO_SUBSTR) {
-               scan_commit(pRExC_state,data,minlenp);  /* Cannot expect anything... */
-               data->pos_min += trie->minlen;
-               data->pos_delta += (trie->maxlen - trie->minlen);
-               if (trie->maxlen != trie->minlen)
-                   data->longest = &(data->longest_float);
-           }
-           if (trie->jump) /* no more substrings -- for now /grr*/
-               flags &= ~SCF_DO_SUBSTR; 
-       }
+           else if (PL_regkind[OP(scan)] == TRIE) {
+               reg_trie_data *trie = (reg_trie_data*)RExC_rx->data->data[ ARG(scan) ];
+               U8*bang=NULL;
+
+               min += trie->minlen;
+               delta += (trie->maxlen - trie->minlen);
+               flags &= ~SCF_DO_STCLASS; /* xxx */
+               if (flags & SCF_DO_SUBSTR) {
+                   scan_commit(pRExC_state,data,minlenp);      /* Cannot expect anything... */
+                   data->pos_min += trie->minlen;
+                   data->pos_delta += (trie->maxlen - trie->minlen);
+                   if (trie->maxlen != trie->minlen)
+                       data->longest = &(data->longest_float);
+               }
+               if (trie->jump) /* no more substrings -- for now /grr*/
+                   flags &= ~SCF_DO_SUBSTR;
+           }
 #endif /* old or new */
-#endif /* TRIE_STUDY_OPT */    
-       /* Else: zero-length, ignore. */
-       scan = regnext(scan);
+#endif /* TRIE_STUDY_OPT */
+           /* Else: zero-length, ignore. */
+           scan = regnext(scan);
+       }
+       DEBUG_PEEP("FEND",scan,depth);
+       scan = frame->next;
+       stopparen = frame->stop;
+       frame = frame->prev;
+
     }
 
   finish:
@@ -3616,23 +3800,24 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
        data->flags &= ~SF_IN_PAR;
     }
     if (flags & SCF_DO_STCLASS_OR)
-       cl_and(data->start_class, &and_with);
+       cl_and(data->start_class, and_withp);
     if (flags & SCF_TRIE_RESTUDY)
         data->flags |=         SCF_TRIE_RESTUDY;
     
     DEBUG_STUDYDATA(data,depth);
     
-    return min;
+    return min < stopmin ? min : stopmin;
 }
 
 STATIC I32
 S_add_data(RExC_state_t *pRExC_state, I32 n, const char *s)
 {
     if (RExC_rx->data) {
+       const U32 count = RExC_rx->data->count;
        Renewc(RExC_rx->data,
-              sizeof(*RExC_rx->data) + sizeof(void*) * (RExC_rx->data->count + n - 1),
+              sizeof(*RExC_rx->data) + sizeof(void*) * (count + n - 1),
               char, struct reg_data);
-       Renew(RExC_rx->data->what, RExC_rx->data->count + n, U8);
+       Renew(RExC_rx->data->what, count + n, U8);
        RExC_rx->data->count += n;
     }
     else {
@@ -3699,14 +3884,17 @@ Perl_reginitcolors(pTHX)
  * Beware that the optimization-preparation code in here knows about some
  * of the structure of the compiled regexp.  [I'll say.]
  */
+
+
+
 #ifndef PERL_IN_XSUB_RE
-#define CORE_ONLY_BLOCK(c) {c}{
 #define RE_ENGINE_PTR &PL_core_reg_engine
 #else
-#define CORE_ONLY_BLOCK(c) {
 extern const struct regexp_engine my_reg_engine;
 #define RE_ENGINE_PTR &my_reg_engine
 #endif
+/* these make a few things look better, to avoid indentation */
+#define BEGIN_BLOCK {
 #define END_BLOCK }
  
 regexp *
@@ -3715,13 +3903,14 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
     dVAR;
     GET_RE_DEBUG_FLAGS_DECL;
     DEBUG_r(if (!PL_colorset) reginitcolors());
-    CORE_ONLY_BLOCK(
+#ifndef PERL_IN_XSUB_RE
+    BEGIN_BLOCK
     /* Dispatch a request to compile a regexp to correct 
        regexp engine. */
     HV * const table = GvHV(PL_hintgv);
     if (table) {
         SV **ptr= hv_fetchs(table, "regcomp", FALSE);
-        if (ptr && SvIOK(*ptr)) {
+        if (ptr && SvIOK(*ptr) && SvIV(*ptr)) {
             const regexp_engine *eng=INT2PTR(regexp_engine*,SvIV(*ptr));
             DEBUG_COMPILE_r({
                 PerlIO_printf(Perl_debug_log, "Using engine %"UVxf"\n",
@@ -3729,7 +3918,10 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
             });            
             return CALLREGCOMP_ENG(eng, exp, xend, pm);
         } 
-    })
+    }
+    END_BLOCK
+#endif
+    BEGIN_BLOCK    
     register regexp *r;
     regnode *scan;
     regnode *first;
@@ -3771,12 +3963,18 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
     RExC_end = xend;
     RExC_naughty = 0;
     RExC_npar = 1;
+    RExC_cpar = 1;
+    RExC_nestroot = 0;
     RExC_size = 0L;
     RExC_emit = &PL_regdummy;
     RExC_whilem_seen = 0;
     RExC_charnames = NULL;
-    RExC_parens = NULL;
+    RExC_open_parens = NULL;
+    RExC_close_parens = NULL;
+    RExC_opend = NULL;
     RExC_paren_names = NULL;
+    RExC_recurse = NULL;
+    RExC_recurse_count = 0;
 
 #if 0 /* REGC() is (currently) a NOP at the first pass.
        * Clever compilers notice this and complain. --jhi */
@@ -3804,6 +4002,11 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
     if (RExC_whilem_seen > 15)
        RExC_whilem_seen = 15;
 
+#ifdef DEBUGGING
+    /* Make room for a sentinel value at the end of the program */
+    RExC_size++;
+#endif
+
     /* Allocate space and zero-initialize. Note, the two step process 
        of zeroing when in debug mode, thus anything assigned has to 
        happen after that */
@@ -3831,11 +4034,14 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
     r->substrs = 0;                    /* Useful during FAIL. */
     r->startp = 0;                     /* Useful during FAIL. */
     r->endp = 0;                       
+    r->swap = NULL; 
     r->paren_names = 0;
     
     if (RExC_seen & REG_SEEN_RECURSE) {
-        Newx(RExC_parens, RExC_npar,regnode *);
-        SAVEFREEPV(RExC_parens);
+        Newxz(RExC_open_parens, RExC_npar,regnode *);
+        SAVEFREEPV(RExC_open_parens);
+        Newxz(RExC_close_parens,RExC_npar,regnode *);
+        SAVEFREEPV(RExC_close_parens);
     }
 
     /* Useful during FAIL. */
@@ -3856,8 +4062,14 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
     RExC_end = xend;
     RExC_naughty = 0;
     RExC_npar = 1;
+    RExC_cpar = 1;
     RExC_emit_start = r->program;
     RExC_emit = r->program;
+#ifdef DEBUGGING
+    /* put a sentinal on the end of the program so we can check for
+       overwrites */
+    r->program[RExC_size].type = 255;
+#endif
     /* Store the count of eval-groups for security checks: */
     RExC_emit->next_off = (RExC_seen_evals > (I32)U16_MAX) ? U16_MAX : (U16)RExC_seen_evals;
     REGC((U8)REG_MAGIC, (char*) RExC_emit++);
@@ -3868,24 +4080,37 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
     /* XXXX To minimize changes to RE engine we always allocate
        3-units-long substrs field. */
     Newx(r->substrs, 1, struct reg_substr_data);
+    if (RExC_recurse_count) {
+        Newxz(RExC_recurse,RExC_recurse_count,regnode *);
+        SAVEFREEPV(RExC_recurse);
+    }
 
 reStudy:
     r->minlen = minlen = sawplus = sawopen = 0;
     Zero(r->substrs, 1, struct reg_substr_data);
-    StructCopy(&zero_scan_data, &data, scan_data_t);
 
 #ifdef TRIE_STUDY_OPT
     if ( restudied ) {
+        U32 seen=RExC_seen;
         DEBUG_OPTIMISE_r(PerlIO_printf(Perl_debug_log,"Restudying\n"));
-        RExC_state=copyRExC_state;
+        
+        RExC_state = copyRExC_state;
+        if (seen & REG_TOP_LEVEL_BRANCHES) 
+            RExC_seen |= REG_TOP_LEVEL_BRANCHES;
+        else
+            RExC_seen &= ~REG_TOP_LEVEL_BRANCHES;
         if (data.last_found) {
             SvREFCNT_dec(data.longest_fixed);
            SvREFCNT_dec(data.longest_float);
            SvREFCNT_dec(data.last_found);
        }
+       StructCopy(&zero_scan_data, &data, scan_data_t);
     } else {
-        copyRExC_state=RExC_state;
+        StructCopy(&zero_scan_data, &data, scan_data_t);
+        copyRExC_state = RExC_state;
     }
+#else
+    StructCopy(&zero_scan_data, &data, scan_data_t);
 #endif    
 
     /* Dig out information for optimizations. */
@@ -3982,7 +4207,8 @@ reStudy:
            first = NEXTOPER(first);
            goto again;
        }
-       else if (!sawopen && (OP(first) == STAR &&
+       else if ((!sawopen || !RExC_sawback) &&
+           (OP(first) == STAR &&
            PL_regkind[OP(NEXTOPER(first))] == REG_ANY) &&
            !(r->reganch & ROPT_ANCH) )
        {
@@ -4026,8 +4252,7 @@ reStudy:
        * it happens that c_offset_min has been invalidated, since the
        * earlier string may buy us something the later one won't.]
        */
-       minlen = 0;
-
+       
        data.longest_fixed = newSVpvs("");
        data.longest_float = newSVpvs("");
        data.last_found = newSVpvs("");
@@ -4040,9 +4265,10 @@ reStudy:
        } else                          /* XXXX Check for BOUND? */
            stclass_flag = 0;
        data.last_closep = &last_close;
-
+        
        minlen = study_chunk(pRExC_state, &first, &minlen, &fake, scan + RExC_size, /* Up to end */
-                            &data, SCF_DO_SUBSTR | SCF_WHILEM_VISITED_POS | stclass_flag,0);
+            &data, -1, NULL, NULL,
+            SCF_DO_SUBSTR | SCF_WHILEM_VISITED_POS | stclass_flag,0);
 
        
         CHECK_RESTUDY_GOTO;
@@ -4210,16 +4436,17 @@ reStudy:
        struct regnode_charclass_class ch_class;
        I32 last_close = 0;
        
-       DEBUG_COMPILE_r(PerlIO_printf(Perl_debug_log, "\n"));
+       DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log, "\nMulti Top Level\n"));
 
        scan = r->program + 1;
        cl_init(pRExC_state, &ch_class);
        data.start_class = &ch_class;
        data.last_closep = &last_close;
 
+        
        minlen = study_chunk(pRExC_state, &scan, &minlen, &fake, scan + RExC_size,
-           &data, SCF_DO_STCLASS_AND|SCF_WHILEM_VISITED_POS,0);
-
+           &data, -1, NULL, NULL, SCF_DO_STCLASS_AND|SCF_WHILEM_VISITED_POS,0);
+        
         CHECK_RESTUDY_GOTO;
 
        r->check_substr = r->check_utf8 = r->anchored_substr = r->anchored_utf8
@@ -4246,6 +4473,11 @@ reStudy:
 
     /* Guard against an embedded (?=) or (?<=) with a longer minlen than
        the "real" pattern. */
+    DEBUG_OPTIMISE_r({
+       PerlIO_printf(Perl_debug_log,"minlen: %"IVdf" r->minlen:%"IVdf"\n",
+           minlen, r->minlen);
+    });
+    r->minlenret = minlen;
     if (r->minlen < minlen) 
         r->minlen = minlen;
     
@@ -4257,15 +4489,25 @@ reStudy:
        r->reganch |= ROPT_EVAL_SEEN;
     if (RExC_seen & REG_SEEN_CANY)
        r->reganch |= ROPT_CANY_SEEN;
+    if (RExC_seen & REG_SEEN_VERBARG)
+       r->reganch |= ROPT_VERBARG_SEEN;
+    if (RExC_seen & REG_SEEN_CUTGROUP)
+       r->reganch |= ROPT_CUTGROUP_SEEN;
     if (RExC_paren_names)
         r->paren_names = (HV*)SvREFCNT_inc(RExC_paren_names);
     else
         r->paren_names = NULL;
                
+    if (RExC_recurse_count) {
+        for ( ; RExC_recurse_count ; RExC_recurse_count-- ) {
+            const regnode *scan = RExC_recurse[RExC_recurse_count-1];
+            ARG2L_SET( scan, RExC_open_parens[ARG(scan)-1] - scan );
+        }
+    }
     Newxz(r->startp, RExC_npar, I32);
     Newxz(r->endp, RExC_npar, I32);
-    
-    DEBUG_r( RX_DEBUG_on(r) );
+    /* assume we don't need to swap parens around before we match */
+
     DEBUG_DUMP_r({
         PerlIO_printf(Perl_debug_log,"Final program:\n");
         regdump(r);
@@ -4290,6 +4532,7 @@ reStudy:
 #undef END_BLOCK
 #undef RE_ENGINE_PTR
 
+#ifndef PERL_IN_XSUB_RE
 SV*
 Perl_reg_named_buff_sv(pTHX_ SV* namesv)
 {
@@ -4323,7 +4566,7 @@ Perl_reg_named_buff_sv(pTHX_ SV* namesv)
         return GvSVn(gv_paren);
     }
 }
-
+#endif
 
 /* Scans the name of a named buffer from the pattern.
  * If flags is REG_RSN_RETURN_NULL returns null.
@@ -4440,6 +4683,10 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags) {
 #define REGTAIL_STUDY(x,y,z) regtail((x),(y),(z),depth+1)
 #endif
 
+/* this idea is borrowed from STR_WITH_LEN in handy.h */
+#define CHECK_WORD(s,v,l)  \
+    (((sizeof(s)-1)==(l)) && (strnEQ(start_verb, (s ""), (sizeof(s)-1))))
+
 STATIC regnode *
 S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
     /* paren: Parenthesized? 0=top, 1=(, inside: changed to letter. */
@@ -4476,6 +4723,111 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
 
     /* Make an OPEN node, if parenthesized. */
     if (paren) {
+        if ( *RExC_parse == '*') { /* (*VERB:ARG) */
+           char *start_verb = RExC_parse;
+           STRLEN verb_len = 0;
+           char *start_arg = NULL;
+           unsigned char op = 0;
+           int argok = 1;
+           int internal_argval = 0; /* internal_argval is only useful if !argok */
+           while ( *RExC_parse && *RExC_parse != ')' ) {
+               if ( *RExC_parse == ':' ) {
+                   start_arg = RExC_parse + 1;
+                   break;
+               }
+               RExC_parse++;
+           }
+           ++start_verb;
+           verb_len = RExC_parse - start_verb;
+           if ( start_arg ) {
+               RExC_parse++;
+               while ( *RExC_parse && *RExC_parse != ')' ) 
+                   RExC_parse++;
+               if ( *RExC_parse != ')' ) 
+                   vFAIL("Unterminated verb pattern argument");
+               if ( RExC_parse == start_arg )
+                   start_arg = NULL;
+           } else {
+               if ( *RExC_parse != ')' )
+                   vFAIL("Unterminated verb pattern");
+           }
+           
+           switch ( *start_verb ) {
+            case 'A':  /* (*ACCEPT) */
+                if ( CHECK_WORD("ACCEPT",start_verb,verb_len) ) {
+                   op = ACCEPT;
+                   internal_argval = RExC_nestroot;
+               }
+               break;
+            case 'C':  /* (*COMMIT) */
+                if ( CHECK_WORD("COMMIT",start_verb,verb_len) )
+                    op = COMMIT;
+                break;
+            case 'F':  /* (*FAIL) */
+                if ( verb_len==1 || CHECK_WORD("FAIL",start_verb,verb_len) ) {
+                   op = OPFAIL;
+                   argok = 0;
+               }
+               break;
+            case ':':  /* (*:NAME) */
+           case 'M':  /* (*MARK:NAME) */
+               if ( verb_len==0 || CHECK_WORD("MARK",start_verb,verb_len) ) {
+                    op = MARKPOINT;
+                    argok = -1;
+                }
+                break;
+            case 'P':  /* (*PRUNE) */
+                if ( CHECK_WORD("PRUNE",start_verb,verb_len) )
+                    op = PRUNE;
+                break;
+            case 'S':   /* (*SKIP) */  
+                if ( CHECK_WORD("SKIP",start_verb,verb_len) ) 
+                    op = SKIP;
+                break;
+            case 'T':  /* (*THEN) */
+                /* [19:06] <TimToady> :: is then */
+                if ( CHECK_WORD("THEN",start_verb,verb_len) ) {
+                    op = CUTGROUP;
+                    RExC_seen |= REG_SEEN_CUTGROUP;
+                }
+                break;
+           }
+           if ( ! op ) {
+               RExC_parse++;
+               vFAIL3("Unknown verb pattern '%.*s'",
+                   verb_len, start_verb);
+           }
+           if ( argok ) {
+                if ( start_arg && internal_argval ) {
+                   vFAIL3("Verb pattern '%.*s' may not have an argument",
+                       verb_len, start_verb); 
+               } else if ( argok < 0 && !start_arg ) {
+                    vFAIL3("Verb pattern '%.*s' has a mandatory argument",
+                       verb_len, start_verb);    
+               } else {
+                   ret = reganode(pRExC_state, op, internal_argval);
+                   if ( ! internal_argval && ! SIZE_ONLY ) {
+                        if (start_arg) {
+                            SV *sv = newSVpvn( start_arg, RExC_parse - start_arg);
+                            ARG(ret) = add_data( pRExC_state, 1, "S" );
+                            RExC_rx->data->data[ARG(ret)]=(void*)sv;
+                            ret->flags = 0;
+                        } else {
+                            ret->flags = 1; 
+                        }
+                    }              
+               }
+               if (!internal_argval)
+                   RExC_seen |= REG_SEEN_VERBARG;
+           } else if ( start_arg ) {
+               vFAIL3("Verb pattern '%.*s' may not have an argument",
+                       verb_len, start_verb);    
+           } else {
+               ret = reg_node(pRExC_state, op);
+           }
+           nextchar(pRExC_state);
+           return ret;
+        } else 
        if (*RExC_parse == '?') { /* (?...) */
            U32 posflags = 0, negflags = 0;
            U32 *flagsp = &posflags;
@@ -4547,6 +4899,11 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
            case '=':           /* (?=...) */
            case '!':           /* (?!...) */
                RExC_seen_zerolen++;
+               if (*RExC_parse == ')') {
+                   ret=reg_node(pRExC_state, OPFAIL);
+                   nextchar(pRExC_state);
+                   return ret;
+               }
            case ':':           /* (?:...) */
            case '>':           /* (?>...) */
                break;
@@ -4566,8 +4923,10 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
            case 'R' :           /* (?R) */
                if (*RExC_parse != ')')
                    FAIL("Sequence (?R) not terminated");
-               reg_node(pRExC_state, SRECURSE);
-               break;           /* (?PARNO) */
+               ret = reg_node(pRExC_state, GOSTART);
+               nextchar(pRExC_state);
+               return ret;
+               /*notreached*/
             { /* named and numeric backreferences */
                 I32 num;
                 char * parse_start;
@@ -4580,27 +4939,64 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                 }
                 goto gen_recurse_regop;
                 /* NOT REACHED */
+            case '+':
+                if (!(RExC_parse[0] >= '1' && RExC_parse[0] <= '9')) {
+                    RExC_parse++;
+                    vFAIL("Illegal pattern");
+                }
+                goto parse_recursion;
+                /* NOT REACHED*/
+            case '-': /* (?-1) */
+                if (!(RExC_parse[0] >= '1' && RExC_parse[0] <= '9')) {
+                    RExC_parse--; /* rewind to let it be handled later */
+                    goto parse_flags;
+                } 
+                /*FALLTHROUGH */
             case '1': case '2': case '3': case '4': /* (?1) */
            case '5': case '6': case '7': case '8': case '9':
                RExC_parse--;
+              parse_recursion:
                num = atoi(RExC_parse);
                parse_start = RExC_parse - 1; /* MJD */
+               if (*RExC_parse == '-')
+                   RExC_parse++;
                while (isDIGIT(*RExC_parse))
                        RExC_parse++;
                if (*RExC_parse!=')') 
                    vFAIL("Expecting close bracket");
                        
               gen_recurse_regop:
-                ret = reganode(pRExC_state, RECURSE, num);
+                if ( paren == '-' ) {
+                    /*
+                    Diagram of capture buffer numbering.
+                    Top line is the normal capture buffer numbers
+                    Botton line is the negative indexing as from
+                    the X (the (?-2))
+
+                    +   1 2    3 4 5 X          6 7
+                       /(a(x)y)(a(b(c(?-2)d)e)f)(g(h))/
+                    -   5 4    3 2 1 X          x x
+
+                    */
+                    num = RExC_npar + num;
+                    if (num < 1)  {
+                        RExC_parse++;
+                        vFAIL("Reference to nonexistent group");
+                    }
+                } else if ( paren == '+' ) {
+                    num = RExC_npar + num - 1;
+                }
+
+                ret = reganode(pRExC_state, GOSUB, num);
                 if (!SIZE_ONLY) {
                    if (num > (I32)RExC_rx->nparens) {
                        RExC_parse++;
                        vFAIL("Reference to nonexistent group");
                    }
-                   ARG2L_SET( ret, 0);
+                   ARG2L_SET( ret, RExC_recurse_count++);
                     RExC_emit++;
                    DEBUG_OPTIMISE_MORE_r(PerlIO_printf(Perl_debug_log,
-                       "Recurse #%"UVuf" to %"IVdf"\n", ARG(ret), ARG2L(ret)));
+                       "Recurse #%"UVuf" to %"IVdf"\n", (UV)ARG(ret), (IV)ARG2L(ret)));
                } else {
                    RExC_size++;
                }
@@ -4755,7 +5151,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                            SIZE_ONLY ? REG_RSN_RETURN_NULL : REG_RSN_RETURN_DATA);
                        parno = sv_dat ? *((I32 *)SvPVX(sv_dat)) : 0;
                    }
-                   ret = reganode(pRExC_state,RECURSEP,parno); 
+                   ret = reganode(pRExC_state,INSUBP,parno); 
                    goto insert_if_check_paren;
                }
                else if (RExC_parse[0] >= '1' && RExC_parse[0] <= '9' ) {
@@ -4879,12 +5275,17 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
          capturing_parens:
            parno = RExC_npar;
            RExC_npar++;
+           
            ret = reganode(pRExC_state, OPEN, parno);
-           if (!SIZE_ONLY && RExC_seen & REG_SEEN_RECURSE) {
-               DEBUG_OPTIMISE_MORE_r(PerlIO_printf(Perl_debug_log,
-                       "Setting paren #%"IVdf" to %d\n", parno, REG_NODE_NUM(ret)));
-               RExC_parens[parno-1]= ret;
-
+           if (!SIZE_ONLY ){
+               if (!RExC_nestroot) 
+                   RExC_nestroot = parno;
+               if (RExC_seen & REG_SEEN_RECURSE) {
+                   DEBUG_OPTIMISE_MORE_r(PerlIO_printf(Perl_debug_log,
+                       "Setting open paren #%"IVdf" to %d\n", 
+                       (IV)parno, REG_NODE_NUM(ret)));
+                   RExC_open_parens[parno-1]= ret;
+               }
            }
             Set_Node_Length(ret, 1); /* MJD */
             Set_Node_Offset(ret, RExC_parse); /* MJD */
@@ -4950,7 +5351,16 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
            ender = reg_node(pRExC_state, TAIL);
            break;
        case 1:
+           RExC_cpar++;
            ender = reganode(pRExC_state, CLOSE, parno);
+           if (!SIZE_ONLY && RExC_seen & REG_SEEN_RECURSE) {
+               DEBUG_OPTIMISE_MORE_r(PerlIO_printf(Perl_debug_log,
+                       "Setting close paren #%"IVdf" to %d\n", 
+                       (IV)parno, REG_NODE_NUM(ender)));
+               RExC_close_parens[parno-1]= ender;
+               if (RExC_nestroot == parno) 
+                   RExC_nestroot = 0;
+           }       
             Set_Node_Offset(ender,RExC_parse+1); /* MJD */
             Set_Node_Length(ender,1); /* MJD */
            break;
@@ -4965,6 +5375,10 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
            break;
        case 0:
            ender = reg_node(pRExC_state, END);
+           if (!SIZE_ONLY) {
+                assert(!RExC_opend); /* there can only be one! */
+                RExC_opend = ender;
+            }
            break;
        }
         REGTAIL(pRExC_state, lastbr, ender);
@@ -5205,10 +5619,6 @@ S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth)
        *flagp = flags;
        return(ret);
     }
-    /* else if (OP(ret)==RECURSE) {
-        RExC_parse++;
-        vFAIL("Illegal quantifier on recursion group");
-    } */
 
 #if 0                          /* Now runtime fix should be reliable. */
 
@@ -5261,12 +5671,27 @@ S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth)
               origparse);
     }
 
-    if (*RExC_parse == '?') {
+    if (RExC_parse < RExC_end && *RExC_parse == '?') {
        nextchar(pRExC_state);
        reginsert(pRExC_state, MINMOD, ret, depth+1);
         REGTAIL(pRExC_state, ret, ret + NODE_STEP_REGNODE);
     }
-    if (ISMULT2(RExC_parse)) {
+#ifndef REG_ALLOW_MINMOD_SUSPEND
+    else
+#endif
+    if (RExC_parse < RExC_end && *RExC_parse == '+') {
+        regnode *ender;
+        nextchar(pRExC_state);
+        ender = reg_node(pRExC_state, SUCCEED);
+        REGTAIL(pRExC_state, ret, ender);
+        reginsert(pRExC_state, SUSPEND, ret, depth+1);
+        ret->flags = 0;
+        ender = reg_node(pRExC_state, TAIL);
+        REGTAIL(pRExC_state, ret, ender);
+        /*ret= ender;*/
+    }
+
+    if (RExC_parse < RExC_end && ISMULT2(RExC_parse)) {
        RExC_parse++;
        vFAIL("Nested quantifiers");
     }
@@ -5542,6 +5967,39 @@ S_reg_namedseq(pTHX_ RExC_state_t *pRExC_state, UV *valuep)
 }
 
 
+/*
+ * reg_recode
+ *
+ * It returns the code point in utf8 for the value in *encp.
+ *    value: a code value in the source encoding
+ *    encp:  a pointer to an Encode object
+ *
+ * If the result from Encode is not a single character,
+ * it returns U+FFFD (Replacement character) and sets *encp to NULL.
+ */
+STATIC UV
+S_reg_recode(pTHX_ const char value, SV **encp)
+{
+    STRLEN numlen = 1;
+    SV * const sv = sv_2mortal(newSVpvn(&value, numlen));
+    const char * const s = encp && *encp ? sv_recode_to_utf8(sv, *encp)
+                                        : SvPVX(sv);
+    const STRLEN newlen = SvCUR(sv);
+    UV uv = UNICODE_REPLACEMENT;
+
+    if (newlen)
+       uv = SvUTF8(sv)
+            ? utf8n_to_uvchr((U8*)s, newlen, &numlen, UTF8_ALLOW_DEFAULT)
+            : *(U8*)s;
+
+    if (!newlen || numlen != newlen) {
+       uv = UNICODE_REPLACEMENT;
+       if (encp)
+           *encp = NULL;
+    }
+    return uv;
+}
+
 
 /*
  - regatom - the lowest level
@@ -5838,11 +6296,20 @@ tryagain:
        case 'c':
        case '0':
            goto defchar;
+       case 'R': 
        case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
            {
-               const I32 num = atoi(RExC_parse);
-
+               I32 num;
+               bool isrel=(*RExC_parse=='R');
+               if (isrel)
+                   RExC_parse++;
+               num = atoi(RExC_parse);
+                if (isrel) {
+                    num = RExC_cpar - num;
+                    if (num < 1)
+                        vFAIL("Reference to nonexistent or unclosed group");
+                }
                if (num > 9 && num >= RExC_npar)
                    goto defchar;
                else {
@@ -5850,8 +6317,16 @@ tryagain:
                    while (isDIGIT(*RExC_parse))
                        RExC_parse++;
 
-                   if (!SIZE_ONLY && num > (I32)RExC_rx->nparens)
-                       vFAIL("Reference to nonexistent group");
+                   if (!SIZE_ONLY) {
+                       if (num > (I32)RExC_rx->nparens)
+                           vFAIL("Reference to nonexistent group");
+                       /* People make this error all the time apparently.
+                          So we cant fail on it, even though we should 
+                       
+                       else if (num >= RExC_cpar)
+                           vFAIL("Reference to unclosed group will always match");
+                       */
+                   }
                    RExC_sawback = 1;
                    ret = reganode(pRExC_state,
                                   (U8)(FOLD ? (LOC ? REFFL : REFF) : REF),
@@ -5940,6 +6415,7 @@ tryagain:
                    case 'p':
                    case 'P':
                     case 'N':
+                    case 'R':
                        --p;
                        goto loopdone;
                    case 'n':
@@ -5990,6 +6466,8 @@ tryagain:
                            ender = grok_hex(p, &numlen, &flags, NULL);
                            p += numlen;
                        }
+                       if (PL_encoding && ender < 0x100)
+                           goto recode_encoding;
                        break;
                    case 'c':
                        p++;
@@ -6009,6 +6487,17 @@ tryagain:
                            --p;
                            goto loopdone;
                        }
+                       if (PL_encoding && ender < 0x100)
+                           goto recode_encoding;
+                       break;
+                   recode_encoding:
+                       {
+                           SV* enc = PL_encoding;
+                           ender = reg_recode((const char)(U8)ender, &enc);
+                           if (!enc && SIZE_ONLY && ckWARN(WARN_REGEXP))
+                               vWARN(p, "Invalid escape in the specified encoding");
+                           RExC_utf8 = 1;
+                       }
                        break;
                    case '\0':
                        if (p >= RExC_end)
@@ -6136,33 +6625,6 @@ tryagain:
        break;
     }
 
-    /* If the encoding pragma is in effect recode the text of
-     * any EXACT-kind nodes. */
-    if (ret && PL_encoding && PL_regkind[OP(ret)] == EXACT) {
-       const STRLEN oldlen = STR_LEN(ret);
-       SV * const sv = sv_2mortal(newSVpvn(STRING(ret), oldlen));
-
-       if (RExC_utf8)
-           SvUTF8_on(sv);
-       if (sv_utf8_downgrade(sv, TRUE)) {
-           const char * const s = sv_recode_to_utf8(sv, PL_encoding);
-           const STRLEN newlen = SvCUR(sv);
-
-           if (SvUTF8(sv))
-               RExC_utf8 = 1;
-           if (!SIZE_ONLY) {
-               GET_RE_DEBUG_FLAGS_DECL;
-               DEBUG_COMPILE_r(PerlIO_printf(Perl_debug_log, "recode %*s to %*s\n",
-                                     (int)oldlen, STRING(ret),
-                                     (int)newlen, s));
-               Copy(s, STRING(ret), newlen, char);
-               STR_LEN(ret) += newlen - oldlen;
-               RExC_emit += STR_SZ(newlen) - STR_SZ(oldlen);
-           } else
-               RExC_size += STR_SZ(newlen) - STR_SZ(oldlen);
-       }
-    }
-
     return(ret);
 }
 
@@ -6533,6 +6995,8 @@ parseit:
                    value = grok_hex(RExC_parse, &numlen, &flags, NULL);
                    RExC_parse += numlen;
                }
+               if (PL_encoding && value < 0x100)
+                   goto recode_encoding;
                break;
            case 'c':
                value = UCHARAT(RExC_parse++);
@@ -6540,13 +7004,24 @@ parseit:
                break;
            case '0': case '1': case '2': case '3': case '4':
            case '5': case '6': case '7': case '8': case '9':
-            {
-                I32 flags = 0;
-               numlen = 3;
-               value = grok_oct(--RExC_parse, &numlen, &flags, NULL);
-               RExC_parse += numlen;
-               break;
-            }
+               {
+                   I32 flags = 0;
+                   numlen = 3;
+                   value = grok_oct(--RExC_parse, &numlen, &flags, NULL);
+                   RExC_parse += numlen;
+                   if (PL_encoding && value < 0x100)
+                       goto recode_encoding;
+                   break;
+               }
+           recode_encoding:
+               {
+                   SV* enc = PL_encoding;
+                   value = reg_recode((const char)(U8)value, &enc);
+                   if (!enc && SIZE_ONLY && ckWARN(WARN_REGEXP))
+                       vWARN(RExC_parse,
+                             "Invalid escape in the specified encoding");
+                   break;
+               }
            default:
                if (!SIZE_ONLY && isALPHA(value) && ckWARN(WARN_REGEXP))
                    vWARN2(RExC_parse,
@@ -7233,6 +7708,11 @@ S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
        RExC_size += 1;
        return(ret);
     }
+#ifdef DEBUGGING
+    if (OP(RExC_emit) == 255)
+        Perl_croak(aTHX_ "panic: reg_node overrun trying to emit %s: %d ",
+            reg_name[op], OP(RExC_emit));
+#endif  
     NODE_ALIGN_FILL(ret);
     ptr = ret;
     FILL_ADVANCE_NODE(ptr, op);
@@ -7249,7 +7729,6 @@ S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
     }
 
     RExC_emit = ptr;
-
     return(ret);
 }
 
@@ -7283,7 +7762,10 @@ S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
        */
        return(ret);
     }
-
+#ifdef DEBUGGING
+    if (OP(RExC_emit) == 255)
+        Perl_croak(aTHX_ "panic: reganode overwriting end of allocated program space");
+#endif 
     NODE_ALIGN_FILL(ret);
     ptr = ret;
     FILL_ADVANCE_NODE_ARG(ptr, op, arg);
@@ -7301,7 +7783,6 @@ S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
     }
             
     RExC_emit = ptr;
-
     return(ret);
 }
 
@@ -7340,14 +7821,25 @@ S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd, U32 depth)
     src = RExC_emit;
     RExC_emit += size;
     dst = RExC_emit;
-    if (RExC_parens) {
+    if (RExC_open_parens) {
         int paren;
+        DEBUG_PARSE_FMT("inst"," - %"IVdf, (IV)RExC_npar);
         for ( paren=0 ; paren < RExC_npar ; paren++ ) {
-            if ( RExC_parens[paren] >= src ) 
-                RExC_parens[paren] += size;
-        }            
+            if ( RExC_open_parens[paren] >= opnd ) {
+                DEBUG_PARSE_FMT("open"," - %d",size);
+                RExC_open_parens[paren] += size;
+            } else {
+                DEBUG_PARSE_FMT("open"," - %s","ok");
+            }
+            if ( RExC_close_parens[paren] >= opnd ) {
+                DEBUG_PARSE_FMT("close"," - %d",size);
+                RExC_close_parens[paren] += size;
+            } else {
+                DEBUG_PARSE_FMT("close"," - %s","ok");
+            }
+        }
     }
-    
+
     while (src > opnd) {
        StructCopy(--src, --dst, regnode);
         if (RExC_offsets) {     /* MJD 20010112 */
@@ -7645,6 +8137,7 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
     GET_RE_DEBUG_FLAGS_DECL;
 
     sv_setpvn(sv, "", 0);
+    
     if (OP(o) > REGNODE_MAX)           /* regnode.type is unsigned */
        /* It would be nice to FAIL() here, but this may be called from
           regexec.c, and it would be hard to supply pRExC_state. */
@@ -7684,7 +8177,7 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
             Perl_sv_catpvf(aTHX_ sv,
                 "<S:%"UVuf"/%"IVdf" W:%"UVuf" L:%"UVuf"/%"UVuf" C:%"UVuf"/%"UVuf">",
                 (UV)trie->startstate,
-                (IV)trie->laststate-1,
+                (IV)trie->statecount-1, /* -1 because of the unused 0 element */
                 (UV)trie->wordcount,
                 (UV)trie->minlen,
                 (UV)trie->maxlen,
@@ -7723,11 +8216,15 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
     }
     else if (k == WHILEM && o->flags)                  /* Ordinal/of */
        Perl_sv_catpvf(aTHX_ sv, "[%d/%d]", o->flags & 0xf, o->flags>>4);
-    else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP) 
+    else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP || OP(o)==ACCEPT
        Perl_sv_catpvf(aTHX_ sv, "%d", (int)ARG(o));    /* Parenth number */
-    else if (k == RECURSE)
+    else if (k == GOSUB) 
        Perl_sv_catpvf(aTHX_ sv, "%d[%+d]", (int)ARG(o),(int)ARG2L(o)); /* Paren and offset */
-    else if (k == LOGICAL)
+    else if (k == VERB) {
+        if (!o->flags) 
+            Perl_sv_catpvf(aTHX_ sv, ":%"SVf, 
+                (SV*)prog->data->data[ ARG( o ) ]);
+    } else if (k == LOGICAL)
        Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
     else if (k == ANYOF) {
        int i, rangestart = -1;
@@ -7922,8 +8419,8 @@ Perl_pregfree(pTHX_ struct regexp *r)
     DEBUG_COMPILE_r({
        if (!PL_colorset)
            reginitcolors();
-       if (RX_DEBUG(r)){
-            SV *dsv= sv_newmortal();
+       {
+           SV *dsv= sv_newmortal();
             RE_PV_QUOTED_DECL(s, (r->reganch & ROPT_UTF8),
                 dsv, r->precomp, r->prelen, 60);
             PerlIO_printf(Perl_debug_log,"%sFreeing REx:%s %s\n", 
@@ -8032,12 +8529,10 @@ Perl_pregfree(pTHX_ struct regexp *r)
                         if (trie->nextword)
                             Safefree(trie->nextword);
 #ifdef DEBUGGING
-                        if (RX_DEBUG(r)) {
-                            if (trie->words)
-                                SvREFCNT_dec((SV*)trie->words);
-                            if (trie->revcharmap)
-                                SvREFCNT_dec((SV*)trie->revcharmap);
-                        }
+                        if (trie->words)
+                            SvREFCNT_dec((SV*)trie->words);
+                        if (trie->revcharmap)
+                            SvREFCNT_dec((SV*)trie->revcharmap);
 #endif
                         Safefree(r->data->data[n]); /* do this last!!!! */
                    }
@@ -8052,6 +8547,11 @@ Perl_pregfree(pTHX_ struct regexp *r)
     }
     Safefree(r->startp);
     Safefree(r->endp);
+    if (r->swap) {
+        Safefree(r->swap->startp);
+        Safefree(r->swap->endp);
+        Safefree(r->swap);
+    }
     Safefree(r);
 }
 
@@ -8094,6 +8594,14 @@ Perl_regdupe(pTHX_ const regexp *r, CLONE_PARAMS *param)
     Copy(r->startp, ret->startp, npar, I32);
     Newx(ret->endp, npar, I32);
     Copy(r->startp, ret->startp, npar, I32);
+    if(r->swap) {
+        Newx(ret->swap, 1, regexp_paren_ofs);
+        /* no need to copy these */
+        Newx(ret->swap->startp, npar, I32);
+        Newx(ret->swap->endp, npar, I32);
+    } else {
+        ret->swap = NULL;
+    }
 
     Newx(ret->substrs, 1, struct reg_substr_data);
     for (s = ret->substrs->data, i = 0; i < 3; i++, s++) {
@@ -8118,7 +8626,7 @@ Perl_regdupe(pTHX_ const regexp *r, CLONE_PARAMS *param)
        for (i = 0; i < count; i++) {
            d->what[i] = r->data->what[i];
            switch (d->what[i]) {
-               /* legal options are one of: sfpont
+               /* legal options are one of: sSfpont
                   see also regcomp.h and pregfree() */
            case 's':
            case 'S':
@@ -8177,6 +8685,7 @@ Perl_regdupe(pTHX_ const regexp *r, CLONE_PARAMS *param)
     ret->precomp        = SAVEPVN(r->precomp, r->prelen);
     ret->refcnt         = r->refcnt;
     ret->minlen         = r->minlen;
+    ret->minlenret      = r->minlenret;
     ret->prelen         = r->prelen;
     ret->nparens        = r->nparens;
     ret->lastparen      = r->lastparen;
@@ -8202,6 +8711,111 @@ Perl_regdupe(pTHX_ const regexp *r, CLONE_PARAMS *param)
 }
 #endif    
 
+/* 
+   reg_stringify() 
+   
+   converts a regexp embedded in a MAGIC struct to its stringified form, 
+   caching the converted form in the struct and returns the cached 
+   string. 
+
+   If lp is nonnull then it is used to return the length of the 
+   resulting string
+   
+   If flags is nonnull and the returned string contains UTF8 then 
+   (flags & 1) will be true.
+   
+   If haseval is nonnull then it is used to return whether the pattern 
+   contains evals.
+   
+   Normally called via macro: 
+   
+        CALLREG_STRINGIFY(mg,0,0);
+        
+   And internally with
+   
+        CALLREG_AS_STR(mg,lp,flags,haseval)        
+    
+   See sv_2pv_flags() in sv.c for an example of internal usage.
+    
+ */
+
+char *
+Perl_reg_stringify(pTHX_ MAGIC *mg, STRLEN *lp, U32 *flags, I32 *haseval ) {
+    dVAR;
+    const regexp * const re = (regexp *)mg->mg_obj;
+
+    if (!mg->mg_ptr) {
+       const char *fptr = "msix";
+       char reflags[6];
+       char ch;
+       int left = 0;
+       int right = 4;
+       bool need_newline = 0;
+       U16 reganch = (U16)((re->reganch & PMf_COMPILETIME) >> 12);
+
+       while((ch = *fptr++)) {
+           if(reganch & 1) {
+               reflags[left++] = ch;
+           }
+           else {
+               reflags[right--] = ch;
+           }
+           reganch >>= 1;
+       }
+       if(left != 4) {
+           reflags[left] = '-';
+           left = 5;
+       }
+
+       mg->mg_len = re->prelen + 4 + left;
+       /*
+        * If /x was used, we have to worry about a regex ending with a
+        * comment later being embedded within another regex. If so, we don't
+        * want this regex's "commentization" to leak out to the right part of
+        * the enclosing regex, we must cap it with a newline.
+        *
+        * So, if /x was used, we scan backwards from the end of the regex. If
+        * we find a '#' before we find a newline, we need to add a newline
+        * ourself. If we find a '\n' first (or if we don't find '#' or '\n'),
+        * we don't need to add anything.  -jfriedl
+        */
+       if (PMf_EXTENDED & re->reganch) {
+           const char *endptr = re->precomp + re->prelen;
+           while (endptr >= re->precomp) {
+               const char c = *(endptr--);
+               if (c == '\n')
+                   break; /* don't need another */
+               if (c == '#') {
+                   /* we end while in a comment, so we need a newline */
+                   mg->mg_len++; /* save space for it */
+                   need_newline = 1; /* note to add it */
+                   break;
+               }
+           }
+       }
+
+       Newx(mg->mg_ptr, mg->mg_len + 1 + left, char);
+       mg->mg_ptr[0] = '(';
+       mg->mg_ptr[1] = '?';
+       Copy(reflags, mg->mg_ptr+2, left, char);
+       *(mg->mg_ptr+left+2) = ':';
+       Copy(re->precomp, mg->mg_ptr+3+left, re->prelen, char);
+       if (need_newline)
+           mg->mg_ptr[mg->mg_len - 2] = '\n';
+       mg->mg_ptr[mg->mg_len - 1] = ')';
+       mg->mg_ptr[mg->mg_len] = 0;
+    }
+    if (haseval) 
+        *haseval = re->program[0].next_off;
+    if (flags)    
+       *flags = ((re->reganch & ROPT_UTF8) ? 1 : 0);
+    
+    if (lp)
+       *lp = mg->mg_len;
+    return mg->mg_ptr;
+}
+
+
 #ifndef PERL_IN_XSUB_RE
 /*
  - regnext - dig the "next" pointer out of a node
@@ -8409,6 +9023,7 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
            DUMPUNTIL(NEXTOPER(node), next);
        }
        else if ( PL_regkind[(U8)op]  == TRIE ) {
+           const regnode *this_trie = node;
            const char op = OP(node);
             const I32 n = ARG(node);
            const reg_ac_data * const ac = op>=AHOCORASICK ?
@@ -8429,18 +9044,19 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
                            PL_colors[0], PL_colors[1],
                            (SvUTF8(*elem_ptr) ? PERL_PV_ESCAPE_UNI : 0) |
                            PERL_PV_PRETTY_ELIPSES    |
-                           PERL_PV_PRETTY_LTGT    
+                           PERL_PV_PRETTY_LTGT
                             )
                             : "???"
                 );
                 if (trie->jump) {
                     U16 dist= trie->jump[word_idx+1];
-                    PerlIO_printf(Perl_debug_log, "(%u)\n",(next - dist) - start);
+                   PerlIO_printf(Perl_debug_log, "(%u)\n",
+                        (dist ? this_trie + dist : next) - start);
                     if (dist) {
                         if (!nextbranch)
-                            nextbranch= next - trie->jump[0];
-                        DUMPUNTIL(next - dist, nextbranch);
-                    } 
+                            nextbranch= this_trie + trie->jump[0];    
+                       DUMPUNTIL(this_trie + dist, nextbranch);
+                    }
                     if (nextbranch && PL_regkind[OP(nextbranch)]==BRANCH)
                         nextbranch= regnext((regnode *)nextbranch);
                 } else {