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regcomp.c: Rmv no-longer used variables and code
[perl5.git] / regcomp.c
index bfb2988..fb10fc3 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -86,6 +86,7 @@
 #endif
 
 #include "dquote_static.c"
+#include "charclass_invlists.h"
 
 #ifdef op
 #undef op
@@ -689,7 +690,7 @@ S_scan_commit(pTHX_ const RExC_state_t *pRExC_state, scan_data_t *data, I32 *min
                    |= ((data->flags & SF_BEFORE_EOL) << SF_FIX_SHIFT_EOL);
            else
                data->flags &= ~SF_FIX_BEFORE_EOL;
-           data->minlen_fixed=minlenp; 
+           data->minlen_fixed=minlenp;
            data->lookbehind_fixed=0;
        }
        else { /* *data->longest == data->longest_float */
@@ -1387,8 +1388,8 @@ is the recommended Unicode-aware way of saying
               scan += len;                                                   \
               len = 0;                                                       \
            } else {                                                          \
-               uvc = utf8n_to_uvuni( (const U8*)uc, UTF8_MAXLEN, &len, uniflags);\
-               uvc = to_uni_fold( uvc, foldbuf, &foldlen );                  \
+               len = UTF8SKIP(uc);\
+               uvc = to_utf8_fold( uc, foldbuf, &foldlen);                   \
                foldlen -= UNISKIP( uvc );                                    \
                scan = foldbuf + UNISKIP( uvc );                              \
            }                                                                 \
@@ -1515,10 +1516,12 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
 #endif
 
     switch (flags) {
+       case EXACT: break;
        case EXACTFA:
        case EXACTFU: folder = PL_fold_latin1; break;
        case EXACTF:  folder = PL_fold; break;
        case EXACTFL: folder = PL_fold_locale; break;
+        default: Perl_croak( aTHX_ "panic! In trie construction, unknown node type %u", (unsigned) flags );
     }
 
     trie = (reg_trie_data *) PerlMemShared_calloc( 1, sizeof(reg_trie_data) );
@@ -1705,7 +1708,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
         DEBUG_TRIE_COMPILE_MORE_r( PerlIO_printf( Perl_debug_log, 
             "%*sCompiling trie using list compiler\n",
             (int)depth * 2 + 2, ""));
-       
+
        trie->states = (reg_trie_state *)
            PerlMemShared_calloc( TRIE_CHARCOUNT(trie) + 2,
                                  sizeof(reg_trie_state) );
@@ -2503,15 +2506,116 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
    }});
 
 
+/* The below joins as many adjacent EXACTish nodes as possible into a single
+ * one, and looks for problematic sequences of characters whose folds vs.
+ * non-folds have sufficiently different lengths, that the optimizer would be
+ * fooled into rejecting legitimate matches of them, and the trie construction
+ * code can't cope with them.  The joining is only done if:
+ * 1) there is room in the current conglomerated node to entirely contain the
+ *    next one.
+ * 2) they are the exact same node type
+ *
+ * The adjacent nodes actually may be separated by NOTHING kind nodes, and
+ * these get optimized out
+ *
+ * If there are problematic code sequences, *min_subtract is set to the delta
+ * that the minimum size of the node can be less than its actual size.  And,
+ * the node type of the result is changed to reflect that it contains these
+ * sequences.
+ *
+ * And *has_exactf_sharp_s is set to indicate whether or not the node is EXACTF
+ * and contains LATIN SMALL LETTER SHARP S
+ *
+ * This is as good a place as any to discuss the design of handling these
+ * problematic sequences.  It's been wrong in Perl for a very long time.  There
+ * are three code points in Unicode whose folded lengths differ so much from
+ * the un-folded lengths that it causes problems for the optimizer and trie
+ * construction.  Why only these are problematic, and not others where lengths
+ * also differ is something I (khw) do not understand.  New versions of Unicode
+ * might add more such code points.  Hopefully the logic in fold_grind.t that
+ * figures out what to test (in part by verifying that each size-combination
+ * gets tested) will catch any that do come along, so they can be added to the
+ * special handling below.  The chances of new ones are actually rather small,
+ * as most, if not all, of the world's scripts that have casefolding have
+ * already been encoded by Unicode.  Also, a number of Unicode's decisions were
+ * made to allow compatibility with pre-existing standards, and almost all of
+ * those have already been dealt with.  These would otherwise be the most
+ * likely candidates for generating further tricky sequences.  In other words,
+ * Unicode by itself is unlikely to add new ones unless it is for compatibility
+ * with pre-existing standards, and there aren't many of those left.
+ *
+ * The previous designs for dealing with these involved assigning a special
+ * node for them.  This approach doesn't work, as evidenced by this example:
+ *      "\xDFs" =~ /s\xDF/ui    # Used to fail before these patches
+ * Both these fold to "sss", but if the pattern is parsed to create a node of
+ * that would match just the \xDF, it won't be able to handle the case where a
+ * successful match would have to cross the node's boundary.  The new approach
+ * that hopefully generally solves the problem generates an EXACTFU_SS node
+ * that is "sss".
+ *
+ * There are a number of components to the approach (a lot of work for just
+ * three code points!):
+ * 1)   This routine examines each EXACTFish node that could contain the
+ *      problematic sequences.  It returns in *min_subtract how much to
+ *      subtract from the the actual length of the string to get a real minimum
+ *      for one that could match it.  This number is usually 0 except for the
+ *      problematic sequences.  This delta is used by the caller to adjust the
+ *      min length of the match, and the delta between min and max, so that the
+ *      optimizer doesn't reject these possibilities based on size constraints.
+ * 2)   These sequences are not currently correctly handled by the trie code
+ *      either, so it changes the joined node type to ops that are not handled
+ *      by trie's, those new ops being EXACTFU_SS and EXACTFU_NO_TRIE.
+ * 3)   This is sufficient for the two Greek sequences (described below), but
+ *      the one involving the Sharp s (\xDF) needs more.  The node type
+ *      EXACTFU_SS is used for an EXACTFU node that contains at least one "ss"
+ *      sequence in it.  For non-UTF-8 patterns and strings, this is the only
+ *      case where there is a possible fold length change.  That means that a
+ *      regular EXACTFU node without UTF-8 involvement doesn't have to concern
+ *      itself with length changes, and so can be processed faster.  regexec.c
+ *      takes advantage of this.  Generally, an EXACTFish node that is in UTF-8
+ *      is pre-folded by regcomp.c.  This saves effort in regex matching.
+ *      However, probably mostly for historical reasons, the pre-folding isn't
+ *      done for non-UTF8 patterns (and it can't be for EXACTF and EXACTFL
+ *      nodes, as what they fold to isn't known until runtime.)  The fold
+ *      possibilities for the non-UTF8 patterns are quite simple, except for
+ *      the sharp s.  All the ones that don't involve a UTF-8 target string
+ *      are members of a fold-pair, and arrays are set up for all of them
+ *      that quickly find the other member of the pair.  It might actually
+ *      be faster to pre-fold these, but it isn't currently done, except for
+ *      the sharp s.  Code elsewhere in this file makes sure that it gets
+ *      folded to 'ss', even if the pattern isn't UTF-8.  This avoids the
+ *      issues described in the next item.
+ * 4)   A problem remains for the sharp s in EXACTF nodes.  Whether it matches
+ *      'ss' or not is not knowable at compile time.  It will match iff the
+ *      target string is in UTF-8, unlike the EXACTFU nodes, where it always
+ *      matches; and the EXACTFL and EXACTFA nodes where it never does.  Thus
+ *      it can't be folded to "ss" at compile time, unlike EXACTFU does as
+ *      described in item 3).  An assumption that the optimizer part of
+ *      regexec.c (probably unwittingly) makes is that a character in the
+ *      pattern corresponds to at most a single character in the target string.
+ *      (And I do mean character, and not byte here, unlike other parts of the
+ *      documentation that have never been updated to account for multibyte
+ *      Unicode.)  This assumption is wrong only in this case, as all other
+ *      cases are either 1-1 folds when no UTF-8 is involved; or is true by
+ *      virtue of having this file pre-fold UTF-8 patterns.   I'm
+ *      reluctant to try to change this assumption, so instead the code punts.
+ *      This routine examines EXACTF nodes for the sharp s, and returns a
+ *      boolean indicating whether or not the node is an EXACTF node that
+ *      contains a sharp s.  When it is true, the caller sets a flag that later
+ *      causes the optimizer in this file to not set values for the floating
+ *      and fixed string lengths, and thus avoids the optimizer code in
+ *      regexec.c that makes the invalid assumption.  Thus, there is no
+ *      optimization based on string lengths for EXACTF nodes that contain the
+ *      sharp s.  This only happens for /id rules (which means the pattern
+ *      isn't in UTF-8).
+ */
 
-
-
-#define JOIN_EXACT(scan,min,flags) \
+#define JOIN_EXACT(scan,min_subtract,has_exactf_sharp_s, flags) \
     if (PL_regkind[OP(scan)] == EXACT) \
-        join_exact(pRExC_state,(scan),(min),(flags),NULL,depth+1)
+        join_exact(pRExC_state,(scan),(min_subtract),has_exactf_sharp_s, (flags),NULL,depth+1)
 
 STATIC U32
-S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, I32 *min, U32 flags,regnode *val, U32 depth) {
+S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, UV *min_subtract, bool *has_exactf_sharp_s, U32 flags,regnode *val, U32 depth) {
     /* Merge several consecutive EXACTish nodes into one. */
     regnode *n = regnext(scan);
     U32 stringok = 1;
@@ -2531,13 +2635,15 @@ S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, I32 *min, U32 flags
     PERL_UNUSED_ARG(val);
 #endif
     DEBUG_PEEP("join",scan,depth);
-    
-    /* Skip NOTHING, merge EXACT*. */
-    while (n &&
-           ( PL_regkind[OP(n)] == NOTHING ||
-             (stringok && (OP(n) == OP(scan))))
+
+    /* Look through the subsequent nodes in the chain.  Skip NOTHING, merge
+     * EXACT ones that are mergeable to the current one. */
+    while (n
+           && (PL_regkind[OP(n)] == NOTHING
+               || (stringok && OP(n) == OP(scan)))
            && NEXT_OFF(n)
-           && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX) {
+           && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX)
+    {
         
         if (OP(n) == TAIL || n > next)
             stringok = 0;
@@ -2554,12 +2660,13 @@ S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, I32 *min, U32 flags
         else if (stringok) {
             const unsigned int oldl = STR_LEN(scan);
             regnode * const nnext = regnext(n);
+
+            if (oldl + STR_LEN(n) > U8_MAX)
+                break;
             
             DEBUG_PEEP("merg",n,depth);
-            
             merged++;
-            if (oldl + STR_LEN(n) > U8_MAX)
-                break;
+
             NEXT_OFF(scan) += NEXT_OFF(n);
             STR_LEN(scan) += STR_LEN(n);
             next = n + NODE_SZ_STR(n);
@@ -2585,67 +2692,180 @@ S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, I32 *min, U32 flags
        }
 #endif
     }
-#define GREEK_SMALL_LETTER_IOTA_WITH_DIALYTIKA_AND_TONOS   0x0390
-#define IOTA_D_T       GREEK_SMALL_LETTER_IOTA_WITH_DIALYTIKA_AND_TONOS
-#define GREEK_SMALL_LETTER_UPSILON_WITH_DIALYTIKA_AND_TONOS    0x03B0
-#define UPSILON_D_T    GREEK_SMALL_LETTER_UPSILON_WITH_DIALYTIKA_AND_TONOS
 
-    if (UTF
-       && ( OP(scan) == EXACTF || OP(scan) == EXACTFU || OP(scan) == EXACTFA)
-       && ( STR_LEN(scan) >= 6 ) )
-    {
-    /*
-    Two problematic code points in Unicode casefolding of EXACT nodes:
-    
-    U+0390 - GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS
-    U+03B0 - GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS
-    
-    which casefold to
-    
-    Unicode                      UTF-8
-    
-    U+03B9 U+0308 U+0301         0xCE 0xB9 0xCC 0x88 0xCC 0x81
-    U+03C5 U+0308 U+0301         0xCF 0x85 0xCC 0x88 0xCC 0x81
-    
-    This means that in case-insensitive matching (or "loose matching",
-    as Unicode calls it), an EXACTF of length six (the UTF-8 encoded byte
-    length of the above casefolded versions) can match a target string
-    of length two (the byte length of UTF-8 encoded U+0390 or U+03B0).
-    This would rather mess up the minimum length computation.
-    
-    What we'll do is to look for the tail four bytes, and then peek
-    at the preceding two bytes to see whether we need to decrease
-    the minimum length by four (six minus two).
-    
-    Thanks to the design of UTF-8, there cannot be false matches:
-    A sequence of valid UTF-8 bytes cannot be a subsequence of
-    another valid sequence of UTF-8 bytes.
-    
-    */
-         char * const s0 = STRING(scan), *s, *t;
-         char * const s1 = s0 + STR_LEN(scan) - 1;
-         char * const s2 = s1 - 4;
+    *min_subtract = 0;
+    *has_exactf_sharp_s = FALSE;
+
+    /* Here, all the adjacent mergeable EXACTish nodes have been merged.  We
+     * can now analyze for sequences of problematic code points.  (Prior to
+     * this final joining, sequences could have been split over boundaries, and
+     * hence missed).  The sequences only happen in folding, hence for any
+     * non-EXACT EXACTish node */
+    if (OP(scan) != EXACT) {
+        U8 *s;
+        U8 * s0 = (U8*) STRING(scan);
+        U8 * const s_end = s0 + STR_LEN(scan);
+
+       /* The below is perhaps overboard, but this allows us to save a test
+        * each time through the loop at the expense of a mask.  This is
+        * because on both EBCDIC and ASCII machines, 'S' and 's' differ by a
+        * single bit.  On ASCII they are 32 apart; on EBCDIC, they are 64.
+        * This uses an exclusive 'or' to find that bit and then inverts it to
+        * form a mask, with just a single 0, in the bit position where 'S' and
+        * 's' differ. */
+       const U8 S_or_s_mask = ~ ('S' ^ 's');
+       const U8 s_masked = 's' & S_or_s_mask;
+
+       /* One pass is made over the node's string looking for all the
+        * possibilities.  to avoid some tests in the loop, there are two main
+        * cases, for UTF-8 patterns (which can't have EXACTF nodes) and
+        * non-UTF-8 */
+       if (UTF) {
+
+           /* There are two problematic Greek code points in Unicode
+            * casefolding
+            *
+            * U+0390 - GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS
+            * U+03B0 - GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS
+            *
+            * which casefold to
+            *
+            * Unicode                      UTF-8
+            *
+            * U+03B9 U+0308 U+0301         0xCE 0xB9 0xCC 0x88 0xCC 0x81
+            * U+03C5 U+0308 U+0301         0xCF 0x85 0xCC 0x88 0xCC 0x81
+             *
+            * This means that in case-insensitive matching (or "loose
+            * matching", as Unicode calls it), an EXACTF of length six (the
+            * UTF-8 encoded byte length of the above casefolded versions) can
+            * match a target string of length two (the byte length of UTF-8
+            * encoded U+0390 or U+03B0).  This would rather mess up the
+            * minimum length computation.  (there are other code points that
+            * also fold to these two sequences, but the delta is smaller)
+            *
+            * If these sequences are found, the minimum length is decreased by
+            * four (six minus two).
+            *
+            * Similarly, 'ss' may match the single char and byte LATIN SMALL
+            * LETTER SHARP S.  We decrease the min length by 1 for each
+            * occurrence of 'ss' found */
+
 #ifdef EBCDIC /* RD tunifold greek 0390 and 03B0 */
-        const char t0[] = "\xaf\x49\xaf\x42";
-#else
-         const char t0[] = "\xcc\x88\xcc\x81";
-#endif
-         const char * const t1 = t0 + 3;
-    
-         for (s = s0 + 2;
-              s < s2 && (t = ninstr(s, s1, t0, t1));
-              s = t + 4) {
-#ifdef EBCDIC
-             if (((U8)t[-1] == 0x68 && (U8)t[-2] == 0xB4) ||
-                 ((U8)t[-1] == 0x46 && (U8)t[-2] == 0xB5))
+#          define U390_first_byte 0xb4
+           const U8 U390_tail[] = "\x68\xaf\x49\xaf\x42";
+#          define U3B0_first_byte 0xb5
+           const U8 U3B0_tail[] = "\x46\xaf\x49\xaf\x42";
 #else
-              if (((U8)t[-1] == 0xB9 && (U8)t[-2] == 0xCE) ||
-                  ((U8)t[-1] == 0x85 && (U8)t[-2] == 0xCF))
+#          define U390_first_byte 0xce
+           const U8 U390_tail[] = "\xb9\xcc\x88\xcc\x81";
+#          define U3B0_first_byte 0xcf
+           const U8 U3B0_tail[] = "\x85\xcc\x88\xcc\x81";
 #endif
-                   *min -= 4;
-         }
+           const U8 len = sizeof(U390_tail); /* (-1 for NUL; +1 for 1st byte;
+                                                yields a net of 0 */
+           /* Examine the string for one of the problematic sequences */
+           for (s = s0;
+                s < s_end - 1; /* Can stop 1 before the end, as minimum length
+                                * sequence we are looking for is 2 */
+                s += UTF8SKIP(s))
+           {
+
+               /* Look for the first byte in each problematic sequence */
+               switch (*s) {
+                   /* We don't have to worry about other things that fold to
+                    * 's' (such as the long s, U+017F), as all above-latin1
+                    * code points have been pre-folded */
+                   case 's':
+                   case 'S':
+
+                        /* Current character is an 's' or 'S'.  If next one is
+                         * as well, we have the dreaded sequence */
+                       if (((*(s+1) & S_or_s_mask) == s_masked)
+                           /* These two node types don't have special handling
+                            * for 'ss' */
+                           && OP(scan) != EXACTFL && OP(scan) != EXACTFA)
+                       {
+                           *min_subtract += 1;
+                           OP(scan) = EXACTFU_SS;
+                           s++;    /* No need to look at this character again */
+                       }
+                       break;
+
+                   case U390_first_byte:
+                       if (s_end - s >= len
+
+                           /* The 1's are because are skipping comparing the
+                            * first byte */
+                           && memEQ(s + 1, U390_tail, len - 1))
+                       {
+                           goto greek_sequence;
+                       }
+                       break;
+
+                   case U3B0_first_byte:
+                       if (! (s_end - s >= len
+                              && memEQ(s + 1, U3B0_tail, len - 1)))
+                       {
+                           break;
+                       }
+                     greek_sequence:
+                       *min_subtract += 4;
+
+                       /* This can't currently be handled by trie's, so change
+                        * the node type to indicate this.  If EXACTFA and
+                        * EXACTFL were ever to be handled by trie's, this
+                        * would have to be changed.  If this node has already
+                        * been changed to EXACTFU_SS in this loop, leave it as
+                        * is.  (I (khw) think it doesn't matter in regexec.c
+                        * for UTF patterns, but no need to change it */
+                       if (OP(scan) == EXACTFU) {
+                           OP(scan) = EXACTFU_NO_TRIE;
+                       }
+                       s += 6; /* We already know what this sequence is.  Skip
+                                  the rest of it */
+                       break;
+               }
+           }
+       }
+       else if (OP(scan) != EXACTFL && OP(scan) != EXACTFA) {
+
+           /* Here, the pattern is not UTF-8.  We need to look only for the
+            * 'ss' sequence, and in the EXACTF case, the sharp s, which can be
+            * in the final position.  Otherwise we can stop looking 1 byte
+            * earlier because have to find both the first and second 's' */
+           const U8* upper = (OP(scan) == EXACTF) ? s_end : s_end -1;
+
+           for (s = s0; s < upper; s++) {
+               switch (*s) {
+                   case 'S':
+                   case 's':
+                       if (s_end - s > 1
+                           && ((*(s+1) & S_or_s_mask) == s_masked))
+                       {
+                           *min_subtract += 1;
+
+                           /* EXACTF nodes need to know that the minimum
+                            * length changed so that a sharp s in the string
+                            * can match this ss in the pattern, but they
+                            * remain EXACTF nodes, as they are not trie'able,
+                            * so don't have to invent a new node type to
+                            * exclude them from the trie code */
+                           if (OP(scan) != EXACTF) {
+                               OP(scan) = EXACTFU_SS;
+                           }
+                           s++;
+                       }
+                       break;
+                   case LATIN_SMALL_LETTER_SHARP_S:
+                       if (OP(scan) == EXACTF) {
+                           *has_exactf_sharp_s = TRUE;
+                       }
+                       break;
+               }
+           }
+       }
     }
-    
+
 #ifdef DEBUGGING
     /* Allow dumping but overwriting the collection of skipped
      * ops and/or strings with fake optimized ops */
@@ -2759,10 +2979,18 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
 
   fake_study_recurse:
     while ( scan && OP(scan) != END && scan < last ){
+        UV min_subtract = 0;    /* How much to subtract from the minimum node
+                                   length to get a real minimum (because the
+                                   folded version may be shorter) */
+       bool has_exactf_sharp_s = FALSE;
        /* Peephole optimizer: */
        DEBUG_STUDYDATA("Peep:", data,depth);
        DEBUG_PEEP("Peep",scan,depth);
-        JOIN_EXACT(scan,&min,0);
+
+        /* Its not clear to khw or hv why this is done here, and not in the
+         * clauses that deal with EXACT nodes.  khw's guess is that it's
+         * because of a previous design */
+        JOIN_EXACT(scan,&min_subtract, &has_exactf_sharp_s, 0);
 
        /* Follow the next-chain of the current node and optimize
           away all the NOTHINGs from it.  */
@@ -2774,7 +3002,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
            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)))
@@ -2796,7 +3024,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
            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
@@ -2804,7 +3032,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                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)
@@ -2941,7 +3169,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                  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);
@@ -3057,6 +3285,9 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
 
 #define TRIE_TYPE_IS_SAFE 1
 
+Note that join_exact() assumes that the other types of EXACTFish nodes are not
+used in tries, so that would have to be updated if this changed
+
 */
 #define TRIE_TYPE_IS_SAFE ((UTF && optype == EXACTFU) || optype==EXACT)
 
@@ -3091,7 +3322,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                         
                         if ( last && TRIE_TYPE_IS_SAFE ) {
                             made= make_trie( pRExC_state, startbranch, first, scan, tail, count, optype, depth+1 );
-#ifdef TRIE_STUDY_OPT  
+#ifdef TRIE_STUDY_OPT
                             if ( ((made == MADE_EXACT_TRIE && 
                                  startbranch == first) 
                                  || ( first_non_open == first )) && 
@@ -3276,9 +3507,24 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                l = utf8_length(s, s + l);
                uc = utf8_to_uvchr(s, NULL);
            }
-           min += l;
-           if (flags & SCF_DO_SUBSTR)
-               data->pos_min += l;
+           else if (has_exactf_sharp_s) {
+               RExC_seen |= REG_SEEN_EXACTF_SHARP_S;
+           }
+           min += l - min_subtract;
+            if (min < 0) {
+                min = 0;
+            }
+            delta += min_subtract;
+           if (flags & SCF_DO_SUBSTR) {
+               data->pos_min += l - min_subtract;
+               if (data->pos_min < 0) {
+                    data->pos_min = 0;
+                }
+                data->pos_delta += min_subtract;
+               if (min_subtract) {
+                   data->longest = &(data->longest_float);
+               }
+           }
            if (flags & SCF_DO_STCLASS_AND) {
                /* Check whether it is compatible with what we know already! */
                int compat = 1;
@@ -3306,8 +3552,22 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                        /* Also set the other member of the fold pair.  In case
                         * that unicode semantics is called for at runtime, use
                         * the full latin1 fold.  (Can't do this for locale,
-                        * because not known until runtime */
+                        * because not known until runtime) */
                        ANYOF_BITMAP_SET(data->start_class, PL_fold_latin1[uc]);
+
+                        /* All other (EXACTFL handled above) folds except under
+                         * /iaa that include s, S, and sharp_s also may include
+                         * the others */
+                       if (OP(scan) != EXACTFA) {
+                           if (uc == 's' || uc == 'S') {
+                               ANYOF_BITMAP_SET(data->start_class,
+                                                LATIN_SMALL_LETTER_SHARP_S);
+                           }
+                           else if (uc == LATIN_SMALL_LETTER_SHARP_S) {
+                               ANYOF_BITMAP_SET(data->start_class, 's');
+                               ANYOF_BITMAP_SET(data->start_class, 'S');
+                           }
+                       }
                    }
                }
                else if (uc >= 0x100) {
@@ -3332,6 +3592,19 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                              * run-time */
                             ANYOF_BITMAP_SET(data->start_class,
                                             PL_fold_latin1[uc]);
+
+                           /* All folds except under /iaa that include s, S,
+                            * and sharp_s also may include the others */
+                           if (OP(scan) != EXACTFA) {
+                               if (uc == 's' || uc == 'S') {
+                                   ANYOF_BITMAP_SET(data->start_class,
+                                                  LATIN_SMALL_LETTER_SHARP_S);
+                               }
+                               else if (uc == LATIN_SMALL_LETTER_SHARP_S) {
+                                   ANYOF_BITMAP_SET(data->start_class, 's');
+                                   ANYOF_BITMAP_SET(data->start_class, 'S');
+                               }
+                           }
                         }
                    }
                    data->start_class->flags &= ~ANYOF_EOS;
@@ -3737,18 +4010,6 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                data->longest = &(data->longest_float);
            }
        }
-       else if (OP(scan) == FOLDCHAR) {
-           int d = ARG(scan) == LATIN_SMALL_LETTER_SHARP_S ? 1 : 2;
-           flags &= ~SCF_DO_STCLASS;
-            min += 1;
-            delta += d;
-            if (flags & SCF_DO_SUBSTR) {
-               SCAN_COMMIT(pRExC_state,data,minlenp);  /* Cannot expect anything... */
-               data->pos_min += 1;
-               data->pos_delta += d;
-               data->longest = &(data->longest_float);
-           }
-       }
        else if (REGNODE_SIMPLE(OP(scan))) {
            int value = 0;
 
@@ -3982,7 +4243,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                    break;
                CASE_SYNST_FNC(VERTWS);
                CASE_SYNST_FNC(HORIZWS);
-               
+
                }
                if (flags & SCF_DO_STCLASS_OR)
                    cl_and(data->start_class, and_withp);
@@ -4363,7 +4624,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                flags &= ~SCF_DO_SUBSTR; 
        }
 #endif /* old or new */
-#endif /* TRIE_STUDY_OPT */    
+#endif /* TRIE_STUDY_OPT */
 
        /* Else: zero-length, ignore. */
        scan = regnext(scan);
@@ -4523,7 +4784,7 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 orig_pm_flags)
     struct regexp *r;
     register regexp_internal *ri;
     STRLEN plen;
-    char  *exp;
+    char* VOL exp;
     char* xend;
     regnode *scan;
     I32 flags;
@@ -4553,7 +4814,70 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 orig_pm_flags)
 
     DEBUG_r(if (!PL_colorset) reginitcolors());
 
-    RExC_utf8 = RExC_orig_utf8 = SvUTF8(pattern);
+    /* Initialize these here instead of as-needed, as is quick and avoids
+     * having to test them each time otherwise */
+    if (! PL_AboveLatin1) {
+       PL_AboveLatin1 = _new_invlist_C_array(AboveLatin1_invlist);
+       PL_ASCII = _new_invlist_C_array(ASCII_invlist);
+       PL_Latin1 = _new_invlist_C_array(Latin1_invlist);
+
+       PL_L1PosixAlnum = _new_invlist_C_array(L1PosixAlnum_invlist);
+       PL_PosixAlnum = _new_invlist_C_array(PosixAlnum_invlist);
+
+       PL_L1PosixAlpha = _new_invlist_C_array(L1PosixAlpha_invlist);
+       PL_PosixAlpha = _new_invlist_C_array(PosixAlpha_invlist);
+
+       PL_PosixBlank = _new_invlist_C_array(PosixBlank_invlist);
+       PL_XPosixBlank = _new_invlist_C_array(XPosixBlank_invlist);
+
+       PL_PosixCntrl = _new_invlist_C_array(PosixCntrl_invlist);
+       PL_XPosixCntrl = _new_invlist_C_array(XPosixCntrl_invlist);
+
+       PL_PosixDigit = _new_invlist_C_array(PosixDigit_invlist);
+
+       PL_L1PosixGraph = _new_invlist_C_array(L1PosixGraph_invlist);
+       PL_PosixGraph = _new_invlist_C_array(PosixGraph_invlist);
+
+       PL_L1PosixAlnum = _new_invlist_C_array(L1PosixAlnum_invlist);
+       PL_PosixAlnum = _new_invlist_C_array(PosixAlnum_invlist);
+
+       PL_HorizSpace = _new_invlist_C_array(HorizSpace_invlist);
+
+       PL_L1PosixLower = _new_invlist_C_array(L1PosixLower_invlist);
+       PL_PosixLower = _new_invlist_C_array(PosixLower_invlist);
+
+       PL_L1PosixPrint = _new_invlist_C_array(L1PosixPrint_invlist);
+       PL_PosixPrint = _new_invlist_C_array(PosixPrint_invlist);
+
+       PL_L1PosixPunct = _new_invlist_C_array(L1PosixPunct_invlist);
+       PL_PosixPunct = _new_invlist_C_array(PosixPunct_invlist);
+
+       PL_PerlSpace = _new_invlist_C_array(PerlSpace_invlist);
+       PL_XPerlSpace = _new_invlist_C_array(XPerlSpace_invlist);
+
+       PL_PosixSpace = _new_invlist_C_array(PosixSpace_invlist);
+       PL_XPosixSpace = _new_invlist_C_array(XPosixSpace_invlist);
+
+       PL_L1PosixUpper = _new_invlist_C_array(L1PosixUpper_invlist);
+       PL_PosixUpper = _new_invlist_C_array(PosixUpper_invlist);
+
+       PL_VertSpace = _new_invlist_C_array(VertSpace_invlist);
+
+       PL_PosixWord = _new_invlist_C_array(PosixWord_invlist);
+       PL_L1PosixWord = _new_invlist_C_array(L1PosixWord_invlist);
+
+       PL_PosixXDigit = _new_invlist_C_array(PosixXDigit_invlist);
+       PL_XPosixXDigit = _new_invlist_C_array(XPosixXDigit_invlist);
+    }
+
+    exp = SvPV(pattern, plen);
+
+    if (plen == 0) { /* ignore the utf8ness if the pattern is 0 length */
+       RExC_utf8 = RExC_orig_utf8 = 0;
+    }
+    else {
+       RExC_utf8 = RExC_orig_utf8 = SvUTF8(pattern);
+    }
     RExC_uni_semantics = 0;
     RExC_contains_locale = 0;
 
@@ -4565,12 +4889,7 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 orig_pm_flags)
     }
 
     if (jump_ret == 0) {    /* First time through */
-       exp = SvPV(pattern, plen);
        xend = exp + plen;
-       /* ignore the utf8ness if the pattern is 0 length */
-       if (plen == 0) {
-           RExC_utf8 = RExC_orig_utf8 = 0;
-       }
 
         DEBUG_COMPILE_r({
             SV *dsv= sv_newmortal();
@@ -4602,7 +4921,9 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 orig_pm_flags)
         -- dmq */
         DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log,
            "UTF8 mismatch! Converting to utf8 for resizing and compile\n"));
-        exp = (char*)Perl_bytes_to_utf8(aTHX_ (U8*)SvPV(pattern, plen), &len);
+        exp = (char*)Perl_bytes_to_utf8(aTHX_
+                                       (U8*)SvPV_nomg(pattern, plen),
+                                       &len);
         xend = exp + len;
         RExC_orig_utf8 = RExC_utf8 = 1;
         SAVEFREEPV(exp);
@@ -4659,7 +4980,11 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 orig_pm_flags)
        * Clever compilers notice this and complain. --jhi */
     REGC((U8)REG_MAGIC, (char*)RExC_emit);
 #endif
-    DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log, "Starting first pass (sizing)\n"));
+    DEBUG_PARSE_r(
+       PerlIO_printf(Perl_debug_log, "Starting first pass (sizing)\n");
+        RExC_lastnum=0;
+        RExC_lastparse=NULL;
+    );
     if (reg(pRExC_state, 0, &flags,1) == NULL) {
        RExC_precomp = NULL;
        return(NULL);
@@ -4911,7 +5236,7 @@ reStudy:
                    sawplus = 1;
                else
                    first += regarglen[OP(first)];
-               
+
                first = NEXTOPER(first);
                first_next= regnext(first);
        }
@@ -4926,7 +5251,7 @@ reStudy:
            else
                ri->regstclass = first;
        }
-#ifdef TRIE_STCLASS    
+#ifdef TRIE_STCLASS
        else if (PL_regkind[OP(first)] == TRIE &&
                ((reg_trie_data *)ri->data->data[ ARG(first) ])->minlen>0) 
        {
@@ -4947,7 +5272,7 @@ reStudy:
             make_trie_failtable(pRExC_state, (regnode *)first, trie_op, 0);
            ri->regstclass = trie_op;
        }
-#endif 
+#endif
        else if (REGNODE_SIMPLE(OP(first)))
            ri->regstclass = first;
        else if (PL_regkind[OP(first)] == BOUND ||
@@ -5013,7 +5338,7 @@ reStudy:
        * it happens that c_offset_min has been invalidated, since the
        * earlier string may buy us something the later one won't.]
        */
-       
+
        data.longest_fixed = newSVpvs("");
        data.longest_float = newSVpvs("");
        data.last_found = newSVpvs("");
@@ -5031,7 +5356,7 @@ reStudy:
             &data, -1, NULL, NULL,
             SCF_DO_SUBSTR | SCF_WHILEM_VISITED_POS | stclass_flag,0);
 
-       
+
         CHECK_RESTUDY_GOTO;
 
 
@@ -5056,9 +5381,11 @@ reStudy:
         {
             I32 t,ml;
 
-           if (SvCUR(data.longest_fixed)  /* ok to leave SvCUR */
-               && data.offset_fixed == data.offset_float_min
-               && SvCUR(data.longest_fixed) == SvCUR(data.longest_float))
+            /* See comments for join_exact for why REG_SEEN_EXACTF_SHARP_S */
+           if ((RExC_seen & REG_SEEN_EXACTF_SHARP_S)
+               || (SvCUR(data.longest_fixed)  /* ok to leave SvCUR */
+                   && data.offset_fixed == data.offset_float_min
+                   && SvCUR(data.longest_fixed) == SvCUR(data.longest_float)))
                    goto remove_float;          /* As in (a)+. */
 
             /* copy the information about the longest float from the reg_scan_data
@@ -5101,10 +5428,13 @@ reStudy:
            Be careful. 
          */
        longest_fixed_length = CHR_SVLEN(data.longest_fixed);
-       if (longest_fixed_length
-           || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
-               && (!(data.flags & SF_FIX_BEFORE_MEOL)
-                   || (RExC_flags & RXf_PMf_MULTILINE)))) 
+
+        /* See comments for join_exact for why REG_SEEN_EXACTF_SHARP_S */
+       if (! (RExC_seen & REG_SEEN_EXACTF_SHARP_S)
+           && (longest_fixed_length
+               || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
+                   && (!(data.flags & SF_FIX_BEFORE_MEOL)
+                       || (RExC_flags & RXf_PMf_MULTILINE)))) )
         {
             I32 t,ml;
 
@@ -5199,7 +5529,7 @@ reStudy:
        I32 fake;
        struct regnode_charclass_class ch_class;
        I32 last_close = 0;
-       
+
        DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log, "\nMulti Top Level\n"));
 
        scan = ri->program + 1;
@@ -5405,7 +5735,8 @@ Perl_reg_named_buff_fetch(pTHX_ REGEXP * const r, SV * const namesv,
                     if (!retarray)
                         return ret;
                 } else {
-                    ret = newSVsv(&PL_sv_undef);
+                    if (retarray)
+                        ret = newSVsv(&PL_sv_undef);
                 }
                 if (retarray)
                     av_push(retarray, ret);
@@ -5769,7 +6100,8 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags)
             return sv_dat;
         }
         else {
-            Perl_croak(aTHX_ "panic: bad flag in reg_scan_name");
+            Perl_croak(aTHX_ "panic: bad flag %lx in reg_scan_name",
+                      (unsigned long) flags);
         }
         /* NOT REACHED */
     }
@@ -5831,8 +6163,8 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags)
  * The 1th element is the first element beyond that not in the list.  In other
  * words, the first range is
  *  invlist[0]..(invlist[1]-1)
- * The other ranges follow.  Thus every element that is divisible by two marks
- * the beginning of a range that is in the list, and every element not
+ * The other ranges follow.  Thus every element whose index is divisible by two
+ * marks the beginning of a range that is in the list, and every element not
  * divisible by two marks the beginning of a range not in the list.  A single
  * element inversion list that contains the single code point N generally
  * consists of two elements
@@ -5865,7 +6197,19 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags)
 #define INVLIST_LEN_OFFSET 0   /* Number of elements in the inversion list */
 #define INVLIST_ITER_OFFSET 1  /* Current iteration position */
 
-#define INVLIST_ZERO_OFFSET 2  /* 0 or 1; must be last element in header */
+/* This is a combination of a version and data structure type, so that one
+ * being passed in can be validated to be an inversion list of the correct
+ * vintage.  When the structure of the header is changed, a new random number
+ * in the range 2**31-1 should be generated and the new() method changed to
+ * insert that at this location.  Then, if an auxiliary program doesn't change
+ * correspondingly, it will be discovered immediately */
+#define INVLIST_VERSION_ID_OFFSET 2
+#define INVLIST_VERSION_ID 1064334010
+
+/* For safety, when adding new elements, remember to #undef them at the end of
+ * the inversion list code section */
+
+#define INVLIST_ZERO_OFFSET 3  /* 0 or 1; must be last element in header */
 /* The UV at position ZERO contains either 0 or 1.  If 0, the inversion list
  * contains the code point U+00000, and begins here.  If 1, the inversion list
  * doesn't contain U+0000, and it begins at the next UV in the array.
@@ -5913,7 +6257,8 @@ S_invlist_array(pTHX_ SV* const invlist)
 
     PERL_ARGS_ASSERT_INVLIST_ARRAY;
 
-    /* Must not be empty */
+    /* Must not be empty.  If these fail, you probably didn't check for <len>
+     * being non-zero before trying to get the array */
     assert(*get_invlist_len_addr(invlist));
     assert(*get_invlist_zero_addr(invlist) == 0
           || *get_invlist_zero_addr(invlist) == 1);
@@ -5939,7 +6284,8 @@ S_get_invlist_len_addr(pTHX_ SV* invlist)
 PERL_STATIC_INLINE UV
 S_invlist_len(pTHX_ SV* const invlist)
 {
-    /* Returns the current number of elements in the inversion list's array */
+    /* Returns the current number of elements stored in the inversion list's
+     * array */
 
     PERL_ARGS_ASSERT_INVLIST_LEN;
 
@@ -5955,6 +6301,8 @@ S_invlist_set_len(pTHX_ SV* const invlist, const UV len)
 
     *get_invlist_len_addr(invlist) = len;
 
+    assert(len <= SvLEN(invlist));
+
     SvCUR_set(invlist, TO_INTERNAL_SIZE(len));
     /* If the list contains U+0000, that element is part of the header,
      * and should not be counted as part of the array.  It will contain
@@ -5964,9 +6312,9 @@ S_invlist_set_len(pTHX_ SV* const invlist, const UV len)
      *           TO_INTERNAL_SIZE(len
      *                            - (*get_invlist_zero_addr(inv_list) ^ 1)));
      * But, this is only valid if len is not 0.  The consequences of not doing
-     * this is that the memory allocation code may think that the 1 more UV
-     * is being used than actually is, and so might do an unnecessary grow.
-     * That seems worth not bothering to make this the precise amount.
+     * this is that the memory allocation code may think that 1 more UV is
+     * being used than actually is, and so might do an unnecessary grow.  That
+     * seems worth not bothering to make this the precise amount.
      *
      * Note that when inverting, SvCUR shouldn't change */
 }
@@ -6021,10 +6369,39 @@ Perl__new_invlist(pTHX_ IV initial_size)
      * properly */
     *get_invlist_zero_addr(new_list) = UV_MAX;
 
+    *get_invlist_version_id_addr(new_list) = INVLIST_VERSION_ID;
+#if HEADER_LENGTH != 4
+#   error Need to regenerate VERSION_ID by running perl -E 'say int(rand 2**31-1)', and then changing the #if to the new length
+#endif
+
     return new_list;
 }
 #endif
 
+STATIC SV*
+S__new_invlist_C_array(pTHX_ UV* list)
+{
+    /* Return a pointer to a newly constructed inversion list, initialized to
+     * point to <list>, which has to be in the exact correct inversion list
+     * form, including internal fields.  Thus this is a dangerous routine that
+     * should not be used in the wrong hands */
+
+    SV* invlist = newSV_type(SVt_PV);
+
+    PERL_ARGS_ASSERT__NEW_INVLIST_C_ARRAY;
+
+    SvPV_set(invlist, (char *) list);
+    SvLEN_set(invlist, 0);  /* Means we own the contents, and the system
+                              shouldn't touch it */
+    SvCUR_set(invlist, TO_INTERNAL_SIZE(invlist_len(invlist)));
+
+    if (*get_invlist_version_id_addr(invlist) != INVLIST_VERSION_ID) {
+        Perl_croak(aTHX_ "panic: Incorrect version for previously generated inversion list");
+    }
+
+    return invlist;
+}
+
 STATIC void
 S_invlist_extend(pTHX_ SV* const invlist, const UV new_max)
 {
@@ -6048,9 +6425,10 @@ S_invlist_trim(pTHX_ SV* const invlist)
 
 /* An element is in an inversion list iff its index is even numbered: 0, 2, 4,
  * etc */
+#define ELEMENT_RANGE_MATCHES_INVLIST(i) (! ((i) & 1))
+#define PREV_RANGE_MATCHES_INVLIST(i) (! ELEMENT_RANGE_MATCHES_INVLIST(i))
 
-#define ELEMENT_IN_INVLIST_SET(i) (! ((i) & 1))
-#define PREV_ELEMENT_IN_INVLIST_SET(i) (! ELEMENT_IN_INVLIST_SET(i))
+#define _invlist_union_complement_2nd(a, b, output) _invlist_union_maybe_complement_2nd(a, b, TRUE, output)
 
 #ifndef PERL_IN_XSUB_RE
 void
@@ -6079,9 +6457,11 @@ Perl__append_range_to_invlist(pTHX_ SV* const invlist, const UV start, const UV
        UV final_element = len - 1;
        array = invlist_array(invlist);
        if (array[final_element] > start
-           || ELEMENT_IN_INVLIST_SET(final_element))
+           || ELEMENT_RANGE_MATCHES_INVLIST(final_element))
        {
-           Perl_croak(aTHX_ "panic: attempting to append to an inversion list, but wasn't at the end of the list");
+           Perl_croak(aTHX_ "panic: attempting to append to an inversion list, but wasn't at the end of the list, final=%"UVuf", start=%"UVuf", match=%c",
+                      array[final_element], start,
+                      ELEMENT_RANGE_MATCHES_INVLIST(final_element) ? 't' : 'f');
        }
 
        /* Here, it is a legal append.  If the new range begins with the first
@@ -6094,7 +6474,7 @@ Perl__append_range_to_invlist(pTHX_ SV* const invlist, const UV start, const UV
            }
            else {
                /* But if the end is the maximum representable on the machine,
-                * just let the range that this would extend have no end */
+                * just let the range that this would extend to have no end */
                invlist_set_len(invlist, len - 1);
            }
            return;
@@ -6129,14 +6509,143 @@ Perl__append_range_to_invlist(pTHX_ SV* const invlist, const UV start, const UV
        invlist_set_len(invlist, len - 1);
     }
 }
-#endif
+
+STATIC IV
+S_invlist_search(pTHX_ SV* const invlist, const UV cp)
+{
+    /* Searches the inversion list for the entry that contains the input code
+     * point <cp>.  If <cp> is not in the list, -1 is returned.  Otherwise, the
+     * return value is the index into the list's array of the range that
+     * contains <cp> */
+
+    IV low = 0;
+    IV high = invlist_len(invlist);
+    const UV * const array = invlist_array(invlist);
+
+    PERL_ARGS_ASSERT_INVLIST_SEARCH;
+
+    /* If list is empty or the code point is before the first element, return
+     * failure. */
+    if (high == 0 || cp < array[0]) {
+       return -1;
+    }
+
+    /* Binary search.  What we are looking for is <i> such that
+     * array[i] <= cp < array[i+1]
+     * The loop below converges on the i+1. */
+    while (low < high) {
+       IV mid = (low + high) / 2;
+       if (array[mid] <= cp) {
+           low = mid + 1;
+
+           /* We could do this extra test to exit the loop early.
+           if (cp < array[low]) {
+               return mid;
+           }
+           */
+       }
+       else { /* cp < array[mid] */
+           high = mid;
+       }
+    }
+
+    return high - 1;
+}
 
 void
-Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
+Perl__invlist_populate_swatch(pTHX_ SV* const invlist, const UV start, const UV end, U8* swatch)
 {
-    /* Take the union of two inversion lists and point 'result' to it.  If
-     * 'result' on input points to one of the two lists, the reference count to
-     * that list will be decremented.
+    /* populates a swatch of a swash the same way swatch_get() does in utf8.c,
+     * but is used when the swash has an inversion list.  This makes this much
+     * faster, as it uses a binary search instead of a linear one.  This is
+     * intimately tied to that function, and perhaps should be in utf8.c,
+     * except it is intimately tied to inversion lists as well.  It assumes
+     * that <swatch> is all 0's on input */
+
+    UV current = start;
+    const IV len = invlist_len(invlist);
+    IV i;
+    const UV * array;
+
+    PERL_ARGS_ASSERT__INVLIST_POPULATE_SWATCH;
+
+    if (len == 0) { /* Empty inversion list */
+        return;
+    }
+
+    array = invlist_array(invlist);
+
+    /* Find which element it is */
+    i = invlist_search(invlist, start);
+
+    /* We populate from <start> to <end> */
+    while (current < end) {
+        UV upper;
+
+       /* The inversion list gives the results for every possible code point
+        * after the first one in the list.  Only those ranges whose index is
+        * even are ones that the inversion list matches.  For the odd ones,
+        * and if the initial code point is not in the list, we have to skip
+        * forward to the next element */
+        if (i == -1 || ! ELEMENT_RANGE_MATCHES_INVLIST(i)) {
+            i++;
+            if (i >= len) { /* Finished if beyond the end of the array */
+                return;
+            }
+            current = array[i];
+           if (current >= end) {   /* Finished if beyond the end of what we
+                                      are populating */
+                return;
+            }
+        }
+        assert(current >= start);
+
+       /* The current range ends one below the next one, except don't go past
+        * <end> */
+        i++;
+        upper = (i < len && array[i] < end) ? array[i] : end;
+
+       /* Here we are in a range that matches.  Populate a bit in the 3-bit U8
+        * for each code point in it */
+        for (; current < upper; current++) {
+            const STRLEN offset = (STRLEN)(current - start);
+            swatch[offset >> 3] |= 1 << (offset & 7);
+        }
+
+       /* Quit if at the end of the list */
+        if (i >= len) {
+
+           /* But first, have to deal with the highest possible code point on
+            * the platform.  The previous code assumes that <end> is one
+            * beyond where we want to populate, but that is impossible at the
+            * platform's infinity, so have to handle it specially */
+            if (UNLIKELY(end == UV_MAX && ELEMENT_RANGE_MATCHES_INVLIST(len-1)))
+           {
+                const STRLEN offset = (STRLEN)(end - start);
+                swatch[offset >> 3] |= 1 << (offset & 7);
+            }
+            return;
+        }
+
+       /* Advance to the next range, which will be for code points not in the
+        * inversion list */
+        current = array[i];
+    }
+
+    return;
+}
+
+
+void
+Perl__invlist_union_maybe_complement_2nd(pTHX_ SV* const a, SV* const b, bool complement_b, SV** output)
+{
+    /* Take the union of two inversion lists and point <output> to it.  *output
+     * should be defined upon input, and if it points to one of the two lists,
+     * the reference count to that list will be decremented.  The first list,
+     * <a>, may be NULL, in which case a copy of the second list is returned.
+     * If <complement_b> is TRUE, the union is taken of the complement
+     * (inversion) of <b> instead of b itself.
+     *
      * The basis for this comes from "Unicode Demystified" Chapter 13 by
      * Richard Gillam, published by Addison-Wesley, and explained at some
      * length there.  The preface says to incorporate its examples into your
@@ -6171,28 +6680,42 @@ Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
      */
     UV count = 0;
 
-    PERL_ARGS_ASSERT__INVLIST_UNION;
+    PERL_ARGS_ASSERT__INVLIST_UNION_MAYBE_COMPLEMENT_2ND;
+    assert(a != b);
 
     /* If either one is empty, the union is the other one */
-    len_a = invlist_len(a);
-    if (len_a == 0) {
-       if (output == &a) {
-           SvREFCNT_dec(a);
+    if (a == NULL || ((len_a = invlist_len(a)) == 0)) {
+       if (*output == a) {
+            if (a != NULL) {
+                SvREFCNT_dec(a);
+            }
        }
-       else if (output != &b) {
+       if (*output != b) {
            *output = invlist_clone(b);
-       }
-       /* else *output already = b; */
+            if (complement_b) {
+                _invlist_invert(*output);
+            }
+       } /* else *output already = b; */
        return;
     }
     else if ((len_b = invlist_len(b)) == 0) {
-       if (output == &b) {
+       if (*output == b) {
            SvREFCNT_dec(b);
        }
-       else if (output != &a) {
-           *output = invlist_clone(a);
-       }
-       /* else *output already = a; */
+
+        /* The complement of an empty list is a list that has everything in it,
+         * so the union with <a> includes everything too */
+        if (complement_b) {
+            if (a == *output) {
+                SvREFCNT_dec(a);
+            }
+            *output = _new_invlist(1);
+            _append_range_to_invlist(*output, 0, UV_MAX);
+        }
+        else if (*output != a) {
+            *output = invlist_clone(a);
+        }
+        /* else *output already = a; */
        return;
     }
 
@@ -6200,6 +6723,31 @@ Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
     array_a = invlist_array(a);
     array_b = invlist_array(b);
 
+    /* If are to take the union of 'a' with the complement of b, set it
+     * up so are looking at b's complement. */
+    if (complement_b) {
+
+       /* To complement, we invert: if the first element is 0, remove it.  To
+        * do this, we just pretend the array starts one later, and clear the
+        * flag as we don't have to do anything else later */
+        if (array_b[0] == 0) {
+            array_b++;
+            len_b--;
+            complement_b = FALSE;
+        }
+        else {
+
+            /* But if the first element is not zero, we unshift a 0 before the
+             * array.  The data structure reserves a space for that 0 (which
+             * should be a '1' right now), so physical shifting is unneeded,
+             * but temporarily change that element to 0.  Before exiting the
+             * routine, we must restore the element to '1' */
+            array_b--;
+            len_b++;
+            array_b[0] = 0;
+        }
+    }
+
     /* Size the union for the worst case: that the sets are completely
      * disjoint */
     u = _new_invlist(len_a + len_b);
@@ -6226,13 +6774,14 @@ Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
         * be seamlessly merged.  (In a tie and both are in the set or both not
         * in the set, it doesn't matter which we take first.) */
        if (array_a[i_a] < array_b[i_b]
-           || (array_a[i_a] == array_b[i_b] && ELEMENT_IN_INVLIST_SET(i_a)))
+           || (array_a[i_a] == array_b[i_b]
+               && ELEMENT_RANGE_MATCHES_INVLIST(i_a)))
        {
-           cp_in_set = ELEMENT_IN_INVLIST_SET(i_a);
+           cp_in_set = ELEMENT_RANGE_MATCHES_INVLIST(i_a);
            cp= array_a[i_a++];
        }
        else {
-           cp_in_set = ELEMENT_IN_INVLIST_SET(i_b);
+           cp_in_set = ELEMENT_RANGE_MATCHES_INVLIST(i_b);
            cp= array_b[i_b++];
        }
 
@@ -6272,8 +6821,8 @@ Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
      * 4) the exhausted wasn't in its set, non-exhausted is, count is 1;
      *    decrementing to 0 insures that we look at the remainder of the
      *    non-exhausted set */
-    if ((i_a != len_a && PREV_ELEMENT_IN_INVLIST_SET(i_a))
-       || (i_b != len_b && PREV_ELEMENT_IN_INVLIST_SET(i_b)))
+    if ((i_a != len_a && PREV_RANGE_MATCHES_INVLIST(i_a))
+       || (i_b != len_b && PREV_RANGE_MATCHES_INVLIST(i_b)))
     {
        count--;
     }
@@ -6313,20 +6862,28 @@ Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
     }
 
     /*  We may be removing a reference to one of the inputs */
-    if (&a == output || &b == output) {
+    if (a == *output || b == *output) {
        SvREFCNT_dec(*output);
     }
 
+    /* If we've changed b, restore it */
+    if (complement_b) {
+        array_b[0] = 1;
+    }
+
     *output = u;
     return;
 }
 
 void
-Perl__invlist_intersection(pTHX_ SV* const a, SV* const b, SV** i)
+Perl__invlist_intersection_maybe_complement_2nd(pTHX_ SV* const a, SV* const b, bool complement_b, SV** i)
 {
-    /* Take the intersection of two inversion lists and point 'i' to it.  If
-     * 'i' on input points to one of the two lists, the reference count to that
-     * list will be decremented.
+    /* Take the intersection of two inversion lists and point <i> to it.  *i
+     * should be defined upon input, and if it points to one of the two lists,
+     * the reference count to that list will be decremented.
+     * If <complement_b> is TRUE, the result will be the intersection of <a>
+     * and the complement (or inversion) of <b> instead of <b> directly.
+     *
      * The basis for this comes from "Unicode Demystified" Chapter 13 by
      * Richard Gillam, published by Addison-Wesley, and explained at some
      * length there.  The preface says to incorporate its examples into your
@@ -6357,21 +6914,39 @@ Perl__invlist_intersection(pTHX_ SV* const a, SV* const b, SV** i)
      */
     UV count = 0;
 
-    PERL_ARGS_ASSERT__INVLIST_INTERSECTION;
+    PERL_ARGS_ASSERT__INVLIST_INTERSECTION_MAYBE_COMPLEMENT_2ND;
+    assert(a != b);
 
-    /* If either one is empty, the intersection is null */
+    /* Special case if either one is empty */
     len_a = invlist_len(a);
     if ((len_a == 0) || ((len_b = invlist_len(b)) == 0)) {
-       *i = _new_invlist(0);
 
-       /* If the result is the same as one of the inputs, the input is being
-        * overwritten */
-       if (i == &a) {
+        if (len_a != 0 && complement_b) {
+
+            /* Here, 'a' is not empty, therefore from the above 'if', 'b' must
+             * be empty.  Here, also we are using 'b's complement, which hence
+             * must be every possible code point.  Thus the intersection is
+             * simply 'a'. */
+            if (*i != a) {
+                *i = invlist_clone(a);
+
+                if (*i == b) {
+                    SvREFCNT_dec(b);
+                }
+            }
+            /* else *i is already 'a' */
+            return;
+        }
+
+        /* Here, 'a' or 'b' is empty and not using the complement of 'b'.  The
+         * intersection must be empty */
+       if (*i == a) {
            SvREFCNT_dec(a);
        }
-       else if (i == &b) {
+       else if (*i == b) {
            SvREFCNT_dec(b);
        }
+       *i = _new_invlist(0);
        return;
     }
 
@@ -6379,6 +6954,31 @@ Perl__invlist_intersection(pTHX_ SV* const a, SV* const b, SV** i)
     array_a = invlist_array(a);
     array_b = invlist_array(b);
 
+    /* If are to take the intersection of 'a' with the complement of b, set it
+     * up so are looking at b's complement. */
+    if (complement_b) {
+
+       /* To complement, we invert: if the first element is 0, remove it.  To
+        * do this, we just pretend the array starts one later, and clear the
+        * flag as we don't have to do anything else later */
+        if (array_b[0] == 0) {
+            array_b++;
+            len_b--;
+            complement_b = FALSE;
+        }
+        else {
+
+            /* But if the first element is not zero, we unshift a 0 before the
+             * array.  The data structure reserves a space for that 0 (which
+             * should be a '1' right now), so physical shifting is unneeded,
+             * but temporarily change that element to 0.  Before exiting the
+             * routine, we must restore the element to '1' */
+            array_b--;
+            len_b++;
+            array_b[0] = 0;
+        }
+    }
+
     /* Size the intersection for the worst case: that the intersection ends up
      * fragmenting everything to be completely disjoint */
     r= _new_invlist(len_a + len_b);
@@ -6406,13 +7006,14 @@ Perl__invlist_intersection(pTHX_ SV* const a, SV* const b, SV** i)
         * momentarily incremented to 2.  (In a tie and both are in the set or
         * both not in the set, it doesn't matter which we take first.) */
        if (array_a[i_a] < array_b[i_b]
-           || (array_a[i_a] == array_b[i_b] && ! ELEMENT_IN_INVLIST_SET(i_a)))
+           || (array_a[i_a] == array_b[i_b]
+               && ! ELEMENT_RANGE_MATCHES_INVLIST(i_a)))
        {
-           cp_in_set = ELEMENT_IN_INVLIST_SET(i_a);
+           cp_in_set = ELEMENT_RANGE_MATCHES_INVLIST(i_a);
            cp= array_a[i_a++];
        }
        else {
-           cp_in_set = ELEMENT_IN_INVLIST_SET(i_b);
+           cp_in_set = ELEMENT_RANGE_MATCHES_INVLIST(i_b);
            cp= array_b[i_b++];
        }
 
@@ -6449,8 +7050,8 @@ Perl__invlist_intersection(pTHX_ SV* const a, SV* const b, SV** i)
      *    everything that remains in the non-exhausted set.
      * 4) the exhausted wasn't in its set, non-exhausted is, count is 1, and
      *    remains 1.  And the intersection has nothing more. */
-    if ((i_a == len_a && PREV_ELEMENT_IN_INVLIST_SET(i_a))
-       || (i_b == len_b && PREV_ELEMENT_IN_INVLIST_SET(i_b)))
+    if ((i_a == len_a && PREV_RANGE_MATCHES_INVLIST(i_a))
+       || (i_b == len_b && PREV_RANGE_MATCHES_INVLIST(i_b)))
     {
        count++;
     }
@@ -6482,14 +7083,21 @@ Perl__invlist_intersection(pTHX_ SV* const a, SV* const b, SV** i)
     }
 
     /*  We may be removing a reference to one of the inputs */
-    if (&a == i || &b == i) {
+    if (a == *i || b == *i) {
        SvREFCNT_dec(*i);
     }
 
+    /* If we've changed b, restore it */
+    if (complement_b) {
+        array_b[0] = 1;
+    }
+
     *i = r;
     return;
 }
 
+#endif
+
 STATIC SV*
 S_add_range_to_invlist(pTHX_ SV* invlist, const UV start, const UV end)
 {
@@ -6537,6 +7145,7 @@ S_add_cp_to_invlist(pTHX_ SV* invlist, const UV cp) {
     return add_range_to_invlist(invlist, cp, cp);
 }
 
+#ifndef PERL_IN_XSUB_RE
 void
 Perl__invlist_invert(pTHX_ SV* const invlist)
 {
@@ -6565,50 +7174,63 @@ Perl__invlist_invert(pTHX_ SV* const invlist)
     }
 }
 
-PERL_STATIC_INLINE SV*
-S_invlist_clone(pTHX_ SV* const invlist)
+void
+Perl__invlist_invert_prop(pTHX_ SV* const invlist)
 {
+    /* Complement the input inversion list (which must be a Unicode property,
+     * all of which don't match above the Unicode maximum code point.)  And
+     * Perl has chosen to not have the inversion match above that either.  This
+     * adds a 0x110000 if the list didn't end with it, and removes it if it did
+     */
 
-    /* Return a new inversion list that is a copy of the input one, which is
-     * unchanged */
+    UV len;
+    UV* array;
 
-    SV* new_invlist = _new_invlist(SvCUR(invlist));
+    PERL_ARGS_ASSERT__INVLIST_INVERT_PROP;
 
-    PERL_ARGS_ASSERT_INVLIST_CLONE;
+    _invlist_invert(invlist);
 
-    Copy(SvPVX(invlist), SvPVX(new_invlist), SvCUR(invlist), char);
-    return new_invlist;
+    len = invlist_len(invlist);
+
+    if (len != 0) { /* If empty do nothing */
+       array = invlist_array(invlist);
+       if (array[len - 1] != PERL_UNICODE_MAX + 1) {
+           /* Add 0x110000.  First, grow if necessary */
+           len++;
+           if (invlist_max(invlist) < len) {
+               invlist_extend(invlist, len);
+               array = invlist_array(invlist);
+           }
+           invlist_set_len(invlist, len);
+           array[len - 1] = PERL_UNICODE_MAX + 1;
+       }
+       else {  /* Remove the 0x110000 */
+           invlist_set_len(invlist, len - 1);
+       }
+    }
+
+    return;
 }
+#endif
 
-void
-Perl__invlist_subtract(pTHX_ SV* const a, SV* const b, SV** result)
+PERL_STATIC_INLINE SV*
+S_invlist_clone(pTHX_ SV* const invlist)
 {
-    /* Point result to an inversion list which consists of all elements in 'a'
-     * that aren't also in 'b' */
 
-    PERL_ARGS_ASSERT__INVLIST_SUBTRACT;
+    /* Return a new inversion list that is a copy of the input one, which is
+     * unchanged */
 
-    /* Subtracting nothing retains the original */
-    if (invlist_len(b) == 0) {
+    /* Need to allocate extra space to accommodate Perl's addition of a
+     * trailing NUL to SvPV's, since it thinks they are always strings */
+    SV* new_invlist = _new_invlist(invlist_len(invlist) + 1);
+    STRLEN length = SvCUR(invlist);
 
-       /* If the result is not to be the same variable as the original, create
-        * a copy */
-       if (result != &a) {
-           *result = invlist_clone(a);
-       }
-    } else {
-       SV *b_copy = invlist_clone(b);
-       _invlist_invert(b_copy);        /* Everything not in 'b' */
-       _invlist_intersection(a, b_copy, result);    /* Everything in 'a' not in
-                                                      'b' */
-       SvREFCNT_dec(b_copy);
-    }
+    PERL_ARGS_ASSERT_INVLIST_CLONE;
 
-    if (result == &b) {
-       SvREFCNT_dec(b);
-    }
+    SvCUR_set(new_invlist, length); /* This isn't done automatically */
+    Copy(SvPVX(invlist), SvPVX(new_invlist), length, char);
 
-    return;
+    return new_invlist;
 }
 
 PERL_STATIC_INLINE UV*
@@ -6622,6 +7244,16 @@ S_get_invlist_iter_addr(pTHX_ SV* invlist)
     return (UV *) (SvPVX(invlist) + (INVLIST_ITER_OFFSET * sizeof (UV)));
 }
 
+PERL_STATIC_INLINE UV*
+S_get_invlist_version_id_addr(pTHX_ SV* invlist)
+{
+    /* Return the address of the UV that contains the version id. */
+
+    PERL_ARGS_ASSERT_GET_INVLIST_VERSION_ID_ADDR;
+
+    return (UV *) (SvPVX(invlist) + (INVLIST_VERSION_ID_OFFSET * sizeof (UV)));
+}
+
 PERL_STATIC_INLINE void
 S_invlist_iterinit(pTHX_ SV* invlist)  /* Initialize iterator for invlist */
 {
@@ -6633,6 +7265,13 @@ S_invlist_iterinit(pTHX_ SV* invlist)    /* Initialize iterator for invlist */
 STATIC bool
 S_invlist_iternext(pTHX_ SV* invlist, UV* start, UV* end)
 {
+    /* An C<invlist_iterinit> call on <invlist> must be used to set this up.
+     * This call sets in <*start> and <*end>, the next range in <invlist>.
+     * Returns <TRUE> if successful and the next call will return the next
+     * range; <FALSE> if was already at the end of the list.  If the latter,
+     * <*start> and <*end> are unchanged, and the next call to this function
+     * will start over at the beginning of the list */
+
     UV* pos = get_invlist_iter_addr(invlist);
     UV len = invlist_len(invlist);
     UV *array;
@@ -6658,6 +7297,37 @@ S_invlist_iternext(pTHX_ SV* invlist, UV* start, UV* end)
     return TRUE;
 }
 
+#ifndef PERL_IN_XSUB_RE
+SV *
+Perl__invlist_contents(pTHX_ SV* const invlist)
+{
+    /* Get the contents of an inversion list into a string SV so that they can
+     * be printed out.  It uses the format traditionally done for debug tracing
+     */
+
+    UV start, end;
+    SV* output = newSVpvs("\n");
+
+    PERL_ARGS_ASSERT__INVLIST_CONTENTS;
+
+    invlist_iterinit(invlist);
+    while (invlist_iternext(invlist, &start, &end)) {
+       if (end == UV_MAX) {
+           Perl_sv_catpvf(aTHX_ output, "%04"UVXf"\tINFINITY\n", start);
+       }
+       else if (end != start) {
+           Perl_sv_catpvf(aTHX_ output, "%04"UVXf"\t%04"UVXf"\n",
+                   start,       end);
+       }
+       else {
+           Perl_sv_catpvf(aTHX_ output, "%04"UVXf"\n", start);
+       }
+    }
+
+    return output;
+}
+#endif
+
 #if 0
 void
 S_invlist_dump(pTHX_ SV* const invlist, const char * const header)
@@ -6689,6 +7359,7 @@ S_invlist_dump(pTHX_ SV* const invlist, const char * const header)
 #undef INVLIST_LEN_OFFSET
 #undef INVLIST_ZERO_OFFSET
 #undef INVLIST_ITER_OFFSET
+#undef INVLIST_VERSION_ID
 
 /* End of inversion list object */
 
@@ -7071,7 +7742,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                        RExC_parse++;
                if (*RExC_parse!=')') 
                    vFAIL("Expecting close bracket");
-                       
+
               gen_recurse_regop:
                 if ( paren == '-' ) {
                     /*
@@ -7148,7 +7819,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                    RExC_parse++;
                }
                if (*RExC_parse != ')') {
-                   RExC_parse = s;             
+                   RExC_parse = s;
                    vFAIL("Sequence (?{...}) not terminated or not {}-balanced");
                }
                if (!SIZE_ONLY) {
@@ -7206,7 +7877,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                        || RExC_parse[1] == '<'
                        || RExC_parse[1] == '{') { /* Lookahead or eval. */
                        I32 flag;
-                       
+
                        ret = reg_node(pRExC_state, LOGICAL);
                        if (!SIZE_ONLY)
                            ret->flags = 1;
@@ -7708,7 +8379,7 @@ S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first, U32 depth)
             Set_Node_Length(ret, 1);
         }
     }
-       
+
     if (!first && SIZE_ONLY)
        RExC_extralen += 1;                     /* BRANCHJ */
 
@@ -8578,7 +9249,7 @@ tryagain:
            break;          
        case 'p':
        case 'P':
-           {   
+           {
                char* const oldregxend = RExC_end;
 #ifdef DEBUGGING
                char* parse_start = RExC_parse - 2;
@@ -8763,41 +9434,51 @@ tryagain:
            RExC_parse++;
 
        defchar: {
-           typedef enum {
-               generic_char = 0,
-               char_s,
-               upsilon_1,
-               upsilon_2,
-               iota_1,
-               iota_2,
-           } char_state;
-           char_state latest_char_state = generic_char;
            register STRLEN len;
            register UV ender;
            register char *p;
            char *s;
            STRLEN foldlen;
            U8 tmpbuf[UTF8_MAXBYTES_CASE+1], *foldbuf;
-           regnode * orig_emit;
+            U8 node_type;
+
+           /* Is this a LATIN LOWER CASE SHARP S in an EXACTFU node?  If so,
+            * it is folded to 'ss' even if not utf8 */
+           bool is_exactfu_sharp_s;
 
            ender = 0;
-           orig_emit = RExC_emit; /* Save the original output node position in
-                                     case we need to output a different node
-                                     type */
-           ret = reg_node(pRExC_state,
-                          (U8) ((! FOLD) ? EXACT
-                                         : (LOC)
-                                            ? EXACTFL
-                                            : (MORE_ASCII_RESTRICTED)
-                                              ? EXACTFA
-                                              : (AT_LEAST_UNI_SEMANTICS)
-                                                ? EXACTFU
-                                                : EXACTF)
-                   );
+            node_type = ((! FOLD) ? EXACT
+                       : (LOC)
+                         ? EXACTFL
+                         : (MORE_ASCII_RESTRICTED)
+                           ? EXACTFA
+                           : (AT_LEAST_UNI_SEMANTICS)
+                             ? EXACTFU
+                             : EXACTF);
+           ret = reg_node(pRExC_state, node_type);
            s = STRING(ret);
+
+           /* XXX The node can hold up to 255 bytes, yet this only goes to
+             * 127.  I (khw) do not know why.  Keeping it somewhat less than
+             * 255 allows us to not have to worry about overflow due to
+             * converting to utf8 and fold expansion, but that value is
+             * 255-UTF8_MAXBYTES_CASE.  join_exact() may join adjacent nodes
+             * split up by this limit into a single one using the real max of
+             * 255.  Even at 127, this breaks under rare circumstances.  If
+             * folding, we do not want to split a node at a character that is a
+             * non-final in a multi-char fold, as an input string could just
+             * happen to want to match across the node boundary.  The join
+             * would solve that problem if the join actually happens.  But a
+             * series of more than two nodes in a row each of 127 would cause
+             * the first join to succeed to get to 254, but then there wouldn't
+             * be room for the next one, which could at be one of those split
+             * multi-char folds.  I don't know of any fool-proof solution.  One
+             * could back off to end with only a code point that isn't such a
+             * non-final, but it is possible for there not to be any in the
+             * entire node. */
            for (len = 0, p = RExC_parse - 1;
-             len < 127 && p < RExC_end;
-             len++)
+                len < 127 && p < RExC_end;
+                len++)
            {
                char * const oldp = p;
 
@@ -8905,7 +9586,7 @@ tryagain:
                    case 'x':
                        if (*++p == '{') {
                            char* const e = strchr(p, '}');
-       
+
                            if (!e) {
                                RExC_parse = p + 1;
                                vFAIL("Missing right brace on \\x{}");
@@ -8990,223 +9671,16 @@ tryagain:
                    break;
                } /* End of switch on the literal */
 
-               /* Certain characters are problematic because their folded
-                * length is so different from their original length that it
-                * isn't handleable by the optimizer.  They are therefore not
-                * placed in an EXACTish node; and are here handled specially.
-                * (Even if the optimizer handled LATIN_SMALL_LETTER_SHARP_S,
-                * putting it in a special node keeps regexec from having to
-                * deal with a non-utf8 multi-char fold */
-               if (FOLD
-                   && (ender > 255 || (! MORE_ASCII_RESTRICTED && ! LOC)))
-               {
-                   /* We look for either side of the fold.  For example \xDF
-                    * folds to 'ss'.  We look for both the single character
-                    * \xDF and the sequence 'ss'.  When we find something that
-                    * could be one of those, we stop and flush whatever we
-                    * have output so far into the EXACTish node that was being
-                    * built.  Then restore the input pointer to what it was.
-                    * regatom will return that EXACT node, and will be called
-                    * again, positioned so the first character is the one in
-                    * question, which we return in a different node type.
-                    * The multi-char folds are a sequence, so the occurrence
-                    * of the first character in that sequence doesn't
-                    * necessarily mean that what follows is the rest of the
-                    * sequence.  We keep track of that with a state machine,
-                    * with the state being set to the latest character
-                    * processed before the current one.  Most characters will
-                    * set the state to 0, but if one occurs that is part of a
-                    * potential tricky fold sequence, the state is set to that
-                    * character, and the next loop iteration sees if the state
-                    * should progress towards the final folded-from character,
-                    * or if it was a false alarm.  If it turns out to be a
-                    * false alarm, the character(s) will be output in a new
-                    * EXACTish node, and join_exact() will later combine them.
-                    * In the case of the 'ss' sequence, which is more common
-                    * and more easily checked, some look-ahead is done to
-                    * save time by ruling-out some false alarms */
-                   switch (ender) {
-                       default:
-                           latest_char_state = generic_char;
-                           break;
-                       case 's':
-                       case 'S':
-                       case 0x17F: /* LATIN SMALL LETTER LONG S */
-                            if (AT_LEAST_UNI_SEMANTICS) {
-                               if (latest_char_state == char_s) {  /* 'ss' */
-                                   ender = LATIN_SMALL_LETTER_SHARP_S;
-                                   goto do_tricky;
-                               }
-                               else if (p < RExC_end) {
-
-                                   /* Look-ahead at the next character.  If it
-                                    * is also an s, we handle as a sharp s
-                                    * tricky regnode.  */
-                                   if (*p == 's' || *p == 'S') {
-
-                                       /* But first flush anything in the
-                                        * EXACTish buffer */
-                                       if (len != 0) {
-                                           p = oldp;
-                                           goto loopdone;
-                                       }
-                                       p++;    /* Account for swallowing this
-                                                  's' up */
-                                       ender = LATIN_SMALL_LETTER_SHARP_S;
-                                       goto do_tricky;
-                                   }
-                                       /* Here, the next character is not a
-                                        * literal 's', but still could
-                                        * evaluate to one if part of a \o{},
-                                        * \x or \OCTAL-DIGIT.  The minimum
-                                        * length required for that is 4, eg
-                                        * \x53 or \123 */
-                                   else if (*p == '\\'
-                                            && p < RExC_end - 4
-                                            && (isDIGIT(*(p + 1))
-                                                || *(p + 1) == 'x'
-                                                || *(p + 1) == 'o' ))
-                                   {
-
-                                       /* Here, it could be an 's', too much
-                                        * bother to figure it out here.  Flush
-                                        * the buffer if any; when come back
-                                        * here, set the state so know that the
-                                        * previous char was an 's' */
-                                       if (len != 0) {
-                                           latest_char_state = generic_char;
-                                           p = oldp;
-                                           goto loopdone;
-                                       }
-                                       latest_char_state = char_s;
-                                       break;
-                                   }
-                               }
-                           }
-
-                           /* Here, can't be an 'ss' sequence, or at least not
-                            * one that could fold to/from the sharp ss */
-                           latest_char_state = generic_char;
-                           break;
-                       case 0x03C5:    /* First char in upsilon series */
-                       case 0x03A5:    /* Also capital UPSILON, which folds to
-                                          03C5, and hence exhibits the same
-                                          problem */
-                           if (p < RExC_end - 4) { /* Need >= 4 bytes left */
-                               latest_char_state = upsilon_1;
-                               if (len != 0) {
-                                   p = oldp;
-                                   goto loopdone;
-                               }
-                           }
-                           else {
-                               latest_char_state = generic_char;
-                           }
-                           break;
-                       case 0x03B9:    /* First char in iota series */
-                       case 0x0399:    /* Also capital IOTA */
-                       case 0x1FBE:    /* GREEK PROSGEGRAMMENI folds to 3B9 */
-                       case 0x0345:    /* COMBINING GREEK YPOGEGRAMMENI folds
-                                          to 3B9 */
-                           if (p < RExC_end - 4) {
-                               latest_char_state = iota_1;
-                               if (len != 0) {
-                                   p = oldp;
-                                   goto loopdone;
-                               }
-                           }
-                           else {
-                               latest_char_state = generic_char;
-                           }
-                           break;
-                       case 0x0308:
-                           if (latest_char_state == upsilon_1) {
-                               latest_char_state = upsilon_2;
-                           }
-                           else if (latest_char_state == iota_1) {
-                               latest_char_state = iota_2;
-                           }
-                           else {
-                               latest_char_state = generic_char;
-                           }
-                           break;
-                       case 0x301:
-                           if (latest_char_state == upsilon_2) {
-                               ender = GREEK_SMALL_LETTER_UPSILON_WITH_DIALYTIKA_AND_TONOS;
-                               goto do_tricky;
-                           }
-                           else if (latest_char_state == iota_2) {
-                               ender = GREEK_SMALL_LETTER_IOTA_WITH_DIALYTIKA_AND_TONOS;
-                               goto do_tricky;
-                           }
-                           latest_char_state = generic_char;
-                           break;
-
-                       /* These are the tricky fold characters.  Flush any
-                        * buffer first. (When adding to this list, also should
-                        * add them to fold_grind.t to make sure get tested) */
-                       case GREEK_SMALL_LETTER_UPSILON_WITH_DIALYTIKA_AND_TONOS:
-                       case GREEK_SMALL_LETTER_IOTA_WITH_DIALYTIKA_AND_TONOS:
-                       case LATIN_SMALL_LETTER_SHARP_S:
-                       case LATIN_CAPITAL_LETTER_SHARP_S:
-                       case 0x1FD3: /* GREEK SMALL LETTER IOTA WITH DIALYTIKA AND OXIA */
-                       case 0x1FE3: /* GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND OXIA */
-                           if (len != 0) {
-                               p = oldp;
-                               goto loopdone;
-                           }
-                           /* FALL THROUGH */
-                       do_tricky: {
-                           char* const oldregxend = RExC_end;
-                           U8 tmpbuf[UTF8_MAXBYTES+1];
-
-                           /* Here, we know we need to generate a special
-                            * regnode, and 'ender' contains the tricky
-                            * character.  What's done is to pretend it's in a
-                            * [bracketed] class, and let the code that deals
-                            * with those handle it, as that code has all the
-                            * intelligence necessary.  First save the current
-                            * parse state, get rid of the already allocated
-                            * but empty EXACT node that the ANYOFV node will
-                            * replace, and point the parse to a buffer which
-                            * we fill with the character we want the regclass
-                            * code to think is being parsed */
-                           RExC_emit = orig_emit;
-                           RExC_parse = (char *) tmpbuf;
-                           if (UTF) {
-                               U8 *d = uvchr_to_utf8(tmpbuf, ender);
-                               *d = '\0';
-                               RExC_end = (char *) d;
-                           }
-                           else {  /* ender above 255 already excluded */
-                               tmpbuf[0] = (U8) ender;
-                               tmpbuf[1] = '\0';
-                               RExC_end = RExC_parse + 1;
-                           }
-
-                           ret = regclass(pRExC_state,depth+1);
-
-                           /* Here, have parsed the buffer.  Reset the parse to
-                            * the actual input, and return */
-                           RExC_end = oldregxend;
-                           RExC_parse = p - 1;
-
-                           Set_Node_Offset(ret, RExC_parse);
-                           Set_Node_Cur_Length(ret);
-                           nextchar(pRExC_state);
-                           *flagp |= HASWIDTH|SIMPLE;
-                           return ret;
-                       }
-                   }
-               }
-
+                is_exactfu_sharp_s = (node_type == EXACTFU
+                                     && ender == LATIN_SMALL_LETTER_SHARP_S);
                if ( RExC_flags & RXf_PMf_EXTENDED)
                    p = regwhite( pRExC_state, p );
-               if (UTF && FOLD) {
+               if ((UTF && FOLD) || is_exactfu_sharp_s) {
                    /* Prime the casefolded buffer.  Locale rules, which apply
                     * only to code points < 256, aren't known until execution,
                     * so for them, just output the original character using
-                    * utf8 */
+                     * utf8.  If we start to fold non-UTF patterns, be sure to
+                     * update join_exact() */
                    if (LOC && ender < 256) {
                        if (UNI_IS_INVARIANT(ender)) {
                            *tmpbuf = (U8) ender;
@@ -9265,7 +9739,7 @@ tryagain:
                if (p < RExC_end && ISMULT2(p)) { /* Back off on ?+*. */
                    if (len)
                        p = oldp;
-                   else if (UTF) {
+                   else if (UTF || is_exactfu_sharp_s) {
                         if (FOLD) {
                              /* Emit all the Unicode characters. */
                              STRLEN numlen;
@@ -9301,7 +9775,7 @@ tryagain:
                    }
                    break;
                }
-               if (UTF) {
+                if (UTF || is_exactfu_sharp_s) {
                     if (FOLD) {
                          /* Emit all the Unicode characters. */
                          STRLEN numlen;
@@ -9351,7 +9825,7 @@ tryagain:
                *flagp |= HASWIDTH;
            if (len == 1 && UNI_IS_INVARIANT(ender))
                *flagp |= SIMPLE;
-               
+
            if (SIZE_ONLY)
                RExC_size += STR_SZ(len);
            else {
@@ -9420,7 +9894,7 @@ S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
        POSIXCC(UCHARAT(RExC_parse))) {
        const char c = UCHARAT(RExC_parse);
        char* const s = RExC_parse++;
-       
+
        while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != c)
            RExC_parse++;
        if (RExC_parse == RExC_end)
@@ -9555,78 +10029,132 @@ S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
     }
 }
 
-/* No locale test, and always Unicode semantics */
-#define _C_C_T_NOLOC_(NAME,TEST,WORD)                                          \
-ANYOF_##NAME:                                                                  \
-       for (value = 0; value < 256; value++)                                  \
-           if (TEST)                                                          \
-           stored += set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);  \
-    yesno = '+';                                                               \
-    what = WORD;                                                               \
-    break;                                                                     \
-case ANYOF_N##NAME:                                                            \
-       for (value = 0; value < 256; value++)                                  \
-           if (!TEST)                                                         \
-           stored += set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);  \
-    yesno = '!';                                                               \
-    what = WORD;                                                               \
-    break
-
-/* Like the above, but there are differences if we are in uni-8-bit or not, so
- * there are two tests passed in, to use depending on that. There aren't any
- * cases where the label is different from the name, so no need for that
- * parameter */
-#define _C_C_T_(NAME, TEST_8, TEST_7, WORD)                                    \
-ANYOF_##NAME:                                                                  \
-    if (LOC) ANYOF_CLASS_SET(ret, ANYOF_##NAME);                               \
-    else if (UNI_SEMANTICS) {                                                  \
-        for (value = 0; value < 256; value++) {                                \
-            if (TEST_8(value)) stored +=                                       \
-                      set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);  \
-        }                                                                      \
-    }                                                                          \
-    else {                                                                     \
-        for (value = 0; value < 128; value++) {                                \
-            if (TEST_7(UNI_TO_NATIVE(value))) stored +=                        \
-               set_regclass_bit(pRExC_state, ret,                     \
-                                  (U8) UNI_TO_NATIVE(value), &l1_fold_invlist, &unicode_alternate);                 \
-        }                                                                      \
-    }                                                                          \
-    yesno = '+';                                                               \
-    what = WORD;                                                               \
-    break;                                                                     \
-case ANYOF_N##NAME:                                                            \
-    if (LOC) ANYOF_CLASS_SET(ret, ANYOF_N##NAME);                              \
-    else if (UNI_SEMANTICS) {                                                  \
-        for (value = 0; value < 256; value++) {                                \
-            if (! TEST_8(value)) stored +=                                     \
-                   set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);    \
-        }                                                                      \
-    }                                                                          \
-    else {                                                                     \
-        for (value = 0; value < 128; value++) {                                \
-            if (! TEST_7(UNI_TO_NATIVE(value))) stored += set_regclass_bit(  \
-                       pRExC_state, ret, (U8) UNI_TO_NATIVE(value), &l1_fold_invlist, &unicode_alternate);    \
-        }                                                                      \
-       if (AT_LEAST_ASCII_RESTRICTED) {                                       \
-           for (value = 128; value < 256; value++) {                          \
-             stored += set_regclass_bit(                                     \
-                          pRExC_state, ret, (U8) UNI_TO_NATIVE(value), &l1_fold_invlist, &unicode_alternate); \
-           }                                                                  \
-           ANYOF_FLAGS(ret) |= ANYOF_UNICODE_ALL;                             \
-       }                                                                      \
-       else {                                                                 \
-           /* For a non-ut8 target string with DEPENDS semantics, all above   \
-            * ASCII Latin1 code points match the complement of any of the     \
-            * classes.  But in utf8, they have their Unicode semantics, so    \
-            * can't just set them in the bitmap, or else regexec.c will think \
-            * they matched when they shouldn't. */                            \
-           ANYOF_FLAGS(ret) |= ANYOF_NON_UTF8_LATIN1_ALL;                     \
-       }                                                                      \
-    }                                                                          \
-    yesno = '!';                                                               \
-    what = WORD;                                                               \
-    break
+/* Generate the code to add a full posix character <class> to the bracketed
+ * character class given by <node>.  (<node> is needed only under locale rules)
+ * destlist     is the inversion list for non-locale rules that this class is
+ *              to be added to
+ * sourcelist   is the ASCII-range inversion list to add under /a rules
+ * Xsourcelist  is the full Unicode range list to use otherwise. */
+#define DO_POSIX(node, class, destlist, sourcelist, Xsourcelist)           \
+    if (LOC) {                                                             \
+       SV* scratch_list = NULL;                                           \
+                                                                           \
+        /* Set this class in the node for runtime matching */              \
+        ANYOF_CLASS_SET(node, class);                                      \
+                                                                           \
+        /* For above Latin1 code points, we use the full Unicode range */  \
+        _invlist_intersection(PL_AboveLatin1,                              \
+                              Xsourcelist,                                 \
+                              &scratch_list);                              \
+        /* And set the output to it, adding instead if there already is an \
+        * output.  Checking if <destlist> is NULL first saves an extra    \
+        * clone.  Its reference count will be decremented at the next     \
+        * union, etc, or if this is the only instance, at the end of the  \
+        * routine */                                                      \
+        if (! destlist) {                                                  \
+            destlist = scratch_list;                                       \
+        }                                                                  \
+        else {                                                             \
+            _invlist_union(destlist, scratch_list, &destlist);             \
+            SvREFCNT_dec(scratch_list);                                    \
+        }                                                                  \
+    }                                                                      \
+    else {                                                                 \
+        /* For non-locale, just add it to any existing list */             \
+        _invlist_union(destlist,                                           \
+                       (AT_LEAST_ASCII_RESTRICTED)                         \
+                           ? sourcelist                                    \
+                           : Xsourcelist,                                  \
+                       &destlist);                                         \
+    }
+
+/* Like DO_POSIX, but matches the complement of <sourcelist> and <Xsourcelist>.
+ */
+#define DO_N_POSIX(node, class, destlist, sourcelist, Xsourcelist)         \
+    if (LOC) {                                                             \
+        SV* scratch_list = NULL;                                           \
+        ANYOF_CLASS_SET(node, class);                                     \
+        _invlist_subtract(PL_AboveLatin1, Xsourcelist, &scratch_list);    \
+        if (! destlist) {                                                 \
+            destlist = scratch_list;                                      \
+        }                                                                  \
+        else {                                                             \
+            _invlist_union(destlist, scratch_list, &destlist);             \
+            SvREFCNT_dec(scratch_list);                                    \
+        }                                                                  \
+    }                                                                      \
+    else {                                                                 \
+        _invlist_union_complement_2nd(destlist,                            \
+                                    (AT_LEAST_ASCII_RESTRICTED)            \
+                                        ? sourcelist                       \
+                                        : Xsourcelist,                     \
+                                    &destlist);                            \
+        /* Under /d, everything in the upper half of the Latin1 range      \
+         * matches this complement */                                      \
+        if (DEPENDS_SEMANTICS) {                                           \
+            ANYOF_FLAGS(node) |= ANYOF_NON_UTF8_LATIN1_ALL;                \
+        }                                                                  \
+    }
+
+/* Generate the code to add a posix character <class> to the bracketed
+ * character class given by <node>.  (<node> is needed only under locale rules)
+ * destlist       is the inversion list for non-locale rules that this class is
+ *                to be added to
+ * sourcelist     is the ASCII-range inversion list to add under /a rules
+ * l1_sourcelist  is the Latin1 range list to use otherwise.
+ * Xpropertyname  is the name to add to <run_time_list> of the property to
+ *                specify the code points above Latin1 that will have to be
+ *                determined at run-time
+ * run_time_list  is a SV* that contains text names of properties that are to
+ *                be computed at run time.  This concatenates <Xpropertyname>
+ *                to it, apppropriately
+ * This is essentially DO_POSIX, but we know only the Latin1 values at compile
+ * time */
+#define DO_POSIX_LATIN1_ONLY_KNOWN(node, class, destlist, sourcelist,      \
+                              l1_sourcelist, Xpropertyname, run_time_list) \
+    /* If not /a matching, there are going to be code points we will have  \
+     * to defer to runtime to look-up */                                   \
+    if (! AT_LEAST_ASCII_RESTRICTED) {                                     \
+        Perl_sv_catpvf(aTHX_ run_time_list, "+utf8::%s\n", Xpropertyname); \
+    }                                                                      \
+    if (LOC) {                                                             \
+        ANYOF_CLASS_SET(node, class);                                      \
+    }                                                                      \
+    else {                                                                 \
+        _invlist_union(destlist,                                           \
+                       (AT_LEAST_ASCII_RESTRICTED)                         \
+                           ? sourcelist                                    \
+                           : l1_sourcelist,                                \
+                       &destlist);                                         \
+    }
+
+/* Like DO_POSIX_LATIN1_ONLY_KNOWN, but for the complement.  A combination of
+ * this and DO_N_POSIX */
+#define DO_N_POSIX_LATIN1_ONLY_KNOWN(node, class, destlist, sourcelist,    \
+                              l1_sourcelist, Xpropertyname, run_time_list) \
+    if (AT_LEAST_ASCII_RESTRICTED) {                                       \
+        _invlist_union_complement_2nd(destlist, sourcelist, &destlist);    \
+    }                                                                      \
+    else {                                                                 \
+        Perl_sv_catpvf(aTHX_ run_time_list, "!utf8::%s\n", Xpropertyname); \
+       if (LOC) {                                                         \
+           ANYOF_CLASS_SET(node, namedclass);                             \
+       }                                                                  \
+       else {                                                             \
+            SV* scratch_list = NULL;                                       \
+           _invlist_subtract(PL_Latin1, l1_sourcelist, &scratch_list);    \
+           if (! destlist) {                                              \
+               destlist = scratch_list;                                   \
+           }                                                              \
+           else {                                                         \
+               _invlist_union(destlist, scratch_list, &destlist);         \
+               SvREFCNT_dec(scratch_list);                                \
+           }                                                              \
+           if (DEPENDS_SEMANTICS) {                                       \
+               ANYOF_FLAGS(node) |= ANYOF_NON_UTF8_LATIN1_ALL;            \
+           }                                                              \
+       }                                                                  \
+    }
 
 STATIC U8
 S_set_regclass_bit_fold(pTHX_ RExC_state_t *pRExC_state, regnode* node, const U8 value, SV** invlist_ptr, AV** alternate_ptr)
@@ -9835,8 +10363,23 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, U32 depth)
     SV *listsv = NULL;
     STRLEN initial_listsv_len = 0; /* Kind of a kludge to see if it is more
                                      than just initialized.  */
+    SV* properties = NULL;    /* Code points that match \p{} \P{} */
+    UV element_count = 0;   /* Number of distinct elements in the class.
+                              Optimizations may be possible if this is tiny */
     UV n;
 
+    /* Unicode properties are stored in a swash; this holds the current one
+     * being parsed.  If this swash is the only above-latin1 component of the
+     * character class, an optimization is to pass it directly on to the
+     * execution engine.  Otherwise, it is set to NULL to indicate that there
+     * are other things in the class that have to be dealt with at execution
+     * time */
+    SV* swash = NULL;          /* Code points that match \p{} \P{} */
+
+    /* Set if a component of this character class is user-defined; just passed
+     * on to the engine */
+    UV has_user_defined_property = 0;
+
     /* code points this node matches that can't be stored in the bitmap */
     SV* nonbitmap = NULL;
 
@@ -9930,8 +10473,10 @@ parseit:
 
        namedclass = OOB_NAMEDCLASS; /* initialize as illegal */
 
-       if (!range)
+       if (!range) {
            rangebegin = RExC_parse;
+           element_count++;
+       }
        if (UTF) {
            value = utf8n_to_uvchr((U8*)RExC_parse,
                                   RExC_end - RExC_parse,
@@ -10007,6 +10552,9 @@ parseit:
                    n = 1;
                }
                if (!SIZE_ONLY) {
+                    SV** invlistsvp;
+                    SV* invlist;
+                    char* name;
                    if (UCHARAT(RExC_parse) == '^') {
                         RExC_parse++;
                         n--;
@@ -10016,24 +10564,88 @@ parseit:
                              n--;
                         }
                    }
+                    /* Try to get the definition of the property into
+                     * <invlist>.  If /i is in effect, the effective property
+                     * will have its name be <__NAME_i>.  The design is
+                     * discussed in commit
+                     * 2f833f5208e26b208886e51e09e2c072b5eabb46 */
+                    Newx(name, n + sizeof("_i__\n"), char);
+
+                    sprintf(name, "%s%.*s%s\n",
+                                    (FOLD) ? "__" : "",
+                                    (int)n,
+                                    RExC_parse,
+                                    (FOLD) ? "_i" : ""
+                    );
+
+                    /* Look up the property name, and get its swash and
+                     * inversion list, if the property is found  */
+                    if (swash) {
+                        SvREFCNT_dec(swash);
+                    }
+                    swash = _core_swash_init("utf8", name, &PL_sv_undef,
+                                             1, /* binary */
+                                             0, /* not tr/// */
+                                             TRUE, /* this routine will handle
+                                                      undefined properties */
+                                             NULL, FALSE /* No inversion list */
+                                            );
+                    if (   ! swash
+                        || ! SvROK(swash)
+                        || ! SvTYPE(SvRV(swash)) == SVt_PVHV
+                        || ! (invlistsvp =
+                               hv_fetchs(MUTABLE_HV(SvRV(swash)),
+                                "INVLIST", FALSE))
+                        || ! (invlist = *invlistsvp))
+                   {
+                        if (swash) {
+                            SvREFCNT_dec(swash);
+                            swash = NULL;
+                        }
 
-                   /* Add the property name to the list.  If /i matching, give
-                    * a different name which consists of the normal name
-                    * sandwiched between two underscores and '_i'.  The design
-                    * is discussed in the commit message for this. */
-                   Perl_sv_catpvf(aTHX_ listsv, "%cutf8::%s%.*s%s\n",
-                                       (value=='p' ? '+' : '!'),
-                                       (FOLD) ? "__" : "",
-                                       (int)n,
-                                       RExC_parse,
-                                       (FOLD) ? "_i" : ""
-                                   );
+                        /* Here didn't find it.  It could be a user-defined
+                         * property that will be available at run-time.  Add it
+                         * to the list to look up then */
+                        Perl_sv_catpvf(aTHX_ listsv, "%cutf8::%s\n",
+                                        (value == 'p' ? '+' : '!'),
+                                        name);
+                        has_user_defined_property = 1;
+
+                        /* We don't know yet, so have to assume that the
+                         * property could match something in the Latin1 range,
+                         * hence something that isn't utf8 */
+                        ANYOF_FLAGS(ret) |= ANYOF_NONBITMAP_NON_UTF8;
+                    }
+                    else {
+
+                        /* Here, did get the swash and its inversion list.  If
+                         * the swash is from a user-defined property, then this
+                         * whole character class should be regarded as such */
+                        SV** user_defined_svp =
+                                            hv_fetchs(MUTABLE_HV(SvRV(swash)),
+                                                        "USER_DEFINED", FALSE);
+                        if (user_defined_svp) {
+                            has_user_defined_property
+                                                    |= SvUV(*user_defined_svp);
+                        }
+
+                        /* Invert if asking for the complement */
+                        if (value == 'P') {
+                           _invlist_union_complement_2nd(properties, invlist, &properties);
+
+                            /* The swash can't be used as-is, because we've
+                            * inverted things; delay removing it to here after
+                            * have copied its invlist above */
+                            SvREFCNT_dec(swash);
+                            swash = NULL;
+                        }
+                        else {
+                            _invlist_union(properties, invlist, &properties);
+                       }
+                   }
+                   Safefree(name);
                }
                RExC_parse = e + 1;
-
-               /* The \p could match something in the Latin1 range, hence
-                * something that isn't utf8 */
-               ANYOF_FLAGS(ret) |= ANYOF_NONBITMAP_NON_UTF8;
                namedclass = ANYOF_MAX;  /* no official name, but it's named */
 
                /* \p means they want Unicode semantics */
@@ -10171,88 +10783,208 @@ parseit:
                range = 0; /* this was not a true range */
            }
 
-
-    
            if (!SIZE_ONLY) {
-               const char *what = NULL;
-               char yesno = 0;
 
                /* Possible truncation here but in some 64-bit environments
                 * the compiler gets heartburn about switch on 64-bit values.
                 * A similar issue a little earlier when switching on value.
                 * --jhi */
                switch ((I32)namedclass) {
-               
-               case _C_C_T_(ALNUMC, isALNUMC_L1, isALNUMC, "XPosixAlnum");
-               case _C_C_T_(ALPHA, isALPHA_L1, isALPHA, "XPosixAlpha");
-               case _C_C_T_(BLANK, isBLANK_L1, isBLANK, "XPosixBlank");
-               case _C_C_T_(CNTRL, isCNTRL_L1, isCNTRL, "XPosixCntrl");
-               case _C_C_T_(GRAPH, isGRAPH_L1, isGRAPH, "XPosixGraph");
-               case _C_C_T_(LOWER, isLOWER_L1, isLOWER, "XPosixLower");
-               case _C_C_T_(PRINT, isPRINT_L1, isPRINT, "XPosixPrint");
-               case _C_C_T_(PSXSPC, isPSXSPC_L1, isPSXSPC, "XPosixSpace");
-               case _C_C_T_(PUNCT, isPUNCT_L1, isPUNCT, "XPosixPunct");
-               case _C_C_T_(UPPER, isUPPER_L1, isUPPER, "XPosixUpper");
-                /* \s, \w match all unicode if utf8. */
-                case _C_C_T_(SPACE, isSPACE_L1, isSPACE, "SpacePerl");
-                case _C_C_T_(ALNUM, isWORDCHAR_L1, isALNUM, "Word");
-               case _C_C_T_(XDIGIT, isXDIGIT_L1, isXDIGIT, "XPosixXDigit");
-               case _C_C_T_NOLOC_(VERTWS, is_VERTWS_latin1(&value), "VertSpace");
-               case _C_C_T_NOLOC_(HORIZWS, is_HORIZWS_latin1(&value), "HorizSpace");
+
+               case ANYOF_ALNUMC: /* C's alnum, in contrast to \w */
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixAlnum, PL_L1PosixAlnum, "XPosixAlnum", listsv);
+                   break;
+               case ANYOF_NALNUMC:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixAlnum, PL_L1PosixAlnum, "XPosixAlnum", listsv);
+                   break;
+               case ANYOF_ALPHA:
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixAlpha, PL_L1PosixAlpha, "XPosixAlpha", listsv);
+                   break;
+               case ANYOF_NALPHA:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixAlpha, PL_L1PosixAlpha, "XPosixAlpha", listsv);
+                   break;
                case ANYOF_ASCII:
-                   if (LOC)
-                       ANYOF_CLASS_SET(ret, ANYOF_ASCII);
-                   else {
-                       for (value = 0; value < 128; value++)
-                           stored +=
-                              set_regclass_bit(pRExC_state, ret, (U8) ASCII_TO_NATIVE(value), &l1_fold_invlist, &unicode_alternate);
+                   if (LOC) {
+                       ANYOF_CLASS_SET(ret, namedclass);
                    }
-                   yesno = '+';
-                   what = NULL;        /* Doesn't match outside ascii, so
-                                          don't want to add +utf8:: */
+                    else {
+                        _invlist_union(properties, PL_ASCII, &properties);
+                    }
                    break;
                case ANYOF_NASCII:
-                   if (LOC)
-                       ANYOF_CLASS_SET(ret, ANYOF_NASCII);
-                   else {
-                       for (value = 128; value < 256; value++)
-                           stored +=
-                              set_regclass_bit(pRExC_state, ret, (U8) ASCII_TO_NATIVE(value), &l1_fold_invlist, &unicode_alternate);
+                   if (LOC) {
+                       ANYOF_CLASS_SET(ret, namedclass);
                    }
-                   ANYOF_FLAGS(ret) |= ANYOF_UNICODE_ALL;
-                   yesno = '!';
-                   what = "ASCII";
-                   break;              
+                    else {
+                        _invlist_union_complement_2nd(properties,
+                                                    PL_ASCII, &properties);
+                        if (DEPENDS_SEMANTICS) {
+                            ANYOF_FLAGS(ret) |= ANYOF_NON_UTF8_LATIN1_ALL;
+                        }
+                    }
+                   break;
+               case ANYOF_BLANK:
+                    DO_POSIX(ret, namedclass, properties,
+                                            PL_PosixBlank, PL_XPosixBlank);
+                   break;
+               case ANYOF_NBLANK:
+                    DO_N_POSIX(ret, namedclass, properties,
+                                            PL_PosixBlank, PL_XPosixBlank);
+                   break;
+               case ANYOF_CNTRL:
+                    DO_POSIX(ret, namedclass, properties,
+                                            PL_PosixCntrl, PL_XPosixCntrl);
+                   break;
+               case ANYOF_NCNTRL:
+                    DO_N_POSIX(ret, namedclass, properties,
+                                            PL_PosixCntrl, PL_XPosixCntrl);
+                   break;
                case ANYOF_DIGIT:
-                   if (LOC)
-                       ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixDigit, PL_PosixDigit, "XPosixDigit", listsv);
+                   break;
+               case ANYOF_NDIGIT:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixDigit, PL_PosixDigit, "XPosixDigit", listsv);
+                   break;
+               case ANYOF_GRAPH:
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixGraph, PL_L1PosixGraph, "XPosixGraph", listsv);
+                   break;
+               case ANYOF_NGRAPH:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixGraph, PL_L1PosixGraph, "XPosixGraph", listsv);
+                   break;
+               case ANYOF_HORIZWS:
+                   /* For these, we use the nonbitmap, as /d doesn't make a
+                    * difference in what these match.  There would be problems
+                    * if these characters had folds other than themselves, as
+                    * nonbitmap is subject to folding */
+                   _invlist_union(nonbitmap, PL_HorizSpace, &nonbitmap);
+                   break;
+               case ANYOF_NHORIZWS:
+                    _invlist_union_complement_2nd(nonbitmap,
+                                                 PL_HorizSpace, &nonbitmap);
+                   break;
+               case ANYOF_LOWER:
+               case ANYOF_NLOWER:
+                {   /* These require special handling, as they differ under
+                       folding, matching the corresponding Alpha property */
+
+                   SV* ascii_source;
+                   SV* l1_source;
+                   const char *Xname;
+
+                   if (FOLD && ! LOC) {
+                       ascii_source = PL_PosixAlpha;
+                       l1_source = PL_L1PosixAlpha;
+                       Xname = "__XposixAlpha_i";
+                   }
                    else {
-                       /* consecutive digits assumed */
-                       for (value = '0'; value <= '9'; value++)
-                           stored +=
-                              set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);
+                       ascii_source = PL_PosixLower;
+                       l1_source = PL_L1PosixLower;
+                       Xname = "XPosixLower";
+                   }
+                   if (namedclass == ANYOF_LOWER) {
+                       DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                                    ascii_source, l1_source, Xname, listsv);
+                   }
+                   else {
+                       DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass,
+                            properties, ascii_source, l1_source, Xname, listsv);
                    }
-                   yesno = '+';
-                   what = "Digit";
                    break;
-               case ANYOF_NDIGIT:
-                   if (LOC)
-                       ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
+               }
+               case ANYOF_PRINT:
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixPrint, PL_L1PosixPrint, "XPosixPrint", listsv);
+                   break;
+               case ANYOF_NPRINT:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixPrint, PL_L1PosixPrint, "XPosixPrint", listsv);
+                   break;
+               case ANYOF_PUNCT:
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixPunct, PL_L1PosixPunct, "XPosixPunct", listsv);
+                   break;
+               case ANYOF_NPUNCT:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixPunct, PL_L1PosixPunct, "XPosixPunct", listsv);
+                   break;
+               case ANYOF_PSXSPC:
+                    DO_POSIX(ret, namedclass, properties,
+                                            PL_PosixSpace, PL_XPosixSpace);
+                   break;
+               case ANYOF_NPSXSPC:
+                    DO_N_POSIX(ret, namedclass, properties,
+                                            PL_PosixSpace, PL_XPosixSpace);
+                   break;
+               case ANYOF_SPACE:
+                    DO_POSIX(ret, namedclass, properties,
+                                            PL_PerlSpace, PL_XPerlSpace);
+                   break;
+               case ANYOF_NSPACE:
+                    DO_N_POSIX(ret, namedclass, properties,
+                                            PL_PerlSpace, PL_XPerlSpace);
+                   break;
+               case ANYOF_UPPER:   /* Same as LOWER, above */
+               case ANYOF_NUPPER:
+               {
+                   SV* ascii_source;
+                   SV* l1_source;
+                   const char *Xname;
+
+                   if (FOLD && ! LOC) {
+                       ascii_source = PL_PosixAlpha;
+                       l1_source = PL_L1PosixAlpha;
+                       Xname = "__XposixAlpha_i";
+                   }
                    else {
-                       /* consecutive digits assumed */
-                       for (value = 0; value < '0'; value++)
-                           stored +=
-                              set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);
-                       for (value = '9' + 1; value < 256; value++)
-                           stored +=
-                              set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);
+                       ascii_source = PL_PosixUpper;
+                       l1_source = PL_L1PosixUpper;
+                       Xname = "XPosixUpper";
                    }
-                   yesno = '!';
-                   what = "Digit";
-                   if (AT_LEAST_ASCII_RESTRICTED ) {
-                       ANYOF_FLAGS(ret) |= ANYOF_UNICODE_ALL;
+                   if (namedclass == ANYOF_UPPER) {
+                       DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                                    ascii_source, l1_source, Xname, listsv);
+                   }
+                   else {
+                       DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass,
+                        properties, ascii_source, l1_source, Xname, listsv);
                    }
-                   break;              
+                   break;
+               }
+               case ANYOF_ALNUM:   /* Really is 'Word' */
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                            PL_PosixWord, PL_L1PosixWord, "XPosixWord", listsv);
+                   break;
+               case ANYOF_NALNUM:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                            PL_PosixWord, PL_L1PosixWord, "XPosixWord", listsv);
+                   break;
+               case ANYOF_VERTWS:
+                   /* For these, we use the nonbitmap, as /d doesn't make a
+                    * difference in what these match.  There would be problems
+                    * if these characters had folds other than themselves, as
+                    * nonbitmap is subject to folding */
+                   _invlist_union(nonbitmap, PL_VertSpace, &nonbitmap);
+                   break;
+               case ANYOF_NVERTWS:
+                    _invlist_union_complement_2nd(nonbitmap,
+                                                    PL_VertSpace, &nonbitmap);
+                   break;
+               case ANYOF_XDIGIT:
+                    DO_POSIX(ret, namedclass, properties,
+                                            PL_PosixXDigit, PL_XPosixXDigit);
+                   break;
+               case ANYOF_NXDIGIT:
+                    DO_N_POSIX(ret, namedclass, properties,
+                                            PL_PosixXDigit, PL_XPosixXDigit);
+                   break;
                case ANYOF_MAX:
                    /* this is to handle \p and \P */
                    break;
@@ -10260,10 +10992,6 @@ parseit:
                    vFAIL("Invalid [::] class");
                    break;
                }
-               if (what && ! (AT_LEAST_ASCII_RESTRICTED)) {
-                   /* Strings such as "+utf8::isWord\n" */
-                   Perl_sv_catpvf(aTHX_ listsv, "%cutf8::Is%s\n", yesno, what);
-               }
 
                continue;
            }
@@ -10365,13 +11093,14 @@ parseit:
     if (FOLD && nonbitmap) {
        UV start, end;  /* End points of code point ranges */
 
-       SV* fold_intersection;
+       SV* fold_intersection = NULL;
 
        /* This is a list of all the characters that participate in folds
            * (except marks, etc in multi-char folds */
        if (! PL_utf8_foldable) {
            SV* swash = swash_init("utf8", "Cased", &PL_sv_undef, 1, 0);
            PL_utf8_foldable = _swash_to_invlist(swash);
+            SvREFCNT_dec(swash);
        }
 
        /* This is a hash that for a particular fold gives all characters
@@ -10392,16 +11121,20 @@ parseit:
                if (! PL_utf8_tofold) {
                    U8 dummy[UTF8_MAXBYTES+1];
                    STRLEN dummy_len;
-                   to_utf8_fold((U8*) "A", dummy, &dummy_len);
+
+                   /* This particular string is above \xff in both UTF-8 and
+                    * UTFEBCDIC */
+                   to_utf8_fold((U8*) "\xC8\x80", dummy, &dummy_len);
+                   assert(PL_utf8_tofold); /* Verify that worked */
                }
                PL_utf8_foldclosures = _swash_inversion_hash(PL_utf8_tofold);
            }
        }
 
-       /* Only the characters in this class that participate in folds need
-           * be checked.  Get the intersection of this class and all the
-           * possible characters that are foldable.  This can quickly narrow
-           * down a large class */
+       /* Only the characters in this class that participate in folds need be
+        * checked.  Get the intersection of this class and all the possible
+        * characters that are foldable.  This can quickly narrow down a large
+        * class */
        _invlist_intersection(PL_utf8_foldable, nonbitmap, &fold_intersection);
 
        /* Now look at the foldable characters in this class individually */
@@ -10420,23 +11153,22 @@ parseit:
 
                if (foldlen > (STRLEN)UNISKIP(f)) {
 
-                   /* Any multicharacter foldings (disallowed in
-                       * lookbehind patterns) require the following
-                       * transform: [ABCDEF] -> (?:[ABCabcDEFd]|pq|rst) where
-                       * E folds into "pq" and F folds into "rst", all other
-                       * characters fold to single characters.  We save away
-                       * these multicharacter foldings, to be later saved as
-                       * part of the additional "s" data. */
+                   /* Any multicharacter foldings (disallowed in lookbehind
+                    * patterns) require the following transform: [ABCDEF] ->
+                    * (?:[ABCabcDEFd]|pq|rst) where E folds into "pq" and F
+                    * folds into "rst", all other characters fold to single
+                    * characters.  We save away these multicharacter foldings,
+                    * to be later saved as part of the additional "s" data. */
                    if (! RExC_in_lookbehind) {
                        U8* loc = foldbuf;
                        U8* e = foldbuf + foldlen;
 
-                       /* If any of the folded characters of this are in
-                           * the Latin1 range, tell the regex engine that
-                           * this can match a non-utf8 target string.  The
-                           * only multi-byte fold whose source is in the
-                           * Latin1 range (U+00DF) applies only when the
-                           * target string is utf8, or under unicode rules */
+                       /* If any of the folded characters of this are in the
+                        * Latin1 range, tell the regex engine that this can
+                        * match a non-utf8 target string.  The only multi-byte
+                        * fold whose source is in the Latin1 range (U+00DF)
+                        * applies only when the target string is utf8, or
+                        * under unicode rules */
                        if (j > 255 || AT_LEAST_UNI_SEMANTICS) {
                            while (loc < e) {
 
@@ -10449,8 +11181,8 @@ parseit:
                                if (UTF8_IS_INVARIANT(*loc)
                                    || UTF8_IS_DOWNGRADEABLE_START(*loc))
                                {
-                                   /* Can't mix above and below 256 under
-                                       * LOC */
+                                    /* Can't mix above and below 256 under LOC
+                                     */
                                    if (LOC) {
                                        goto end_multi_fold;
                                    }
@@ -10480,13 +11212,13 @@ parseit:
                }
                else {
                    /* Single character fold.  Add everything in its fold
-                       * closure to the list that this node should match */
+                    * closure to the list that this node should match */
                    SV** listp;
 
-                   /* The fold closures data structure is a hash with the
-                       * keys being every character that is folded to, like
-                       * 'k', and the values each an array of everything that
-                       * folds to its key.  e.g. [ 'k', 'K', KELVIN_SIGN ] */
+                   /* The fold closures data structure is a hash with the keys
+                    * being every character that is folded to, like 'k', and
+                    * the values each an array of everything that folds to its
+                    * key.  e.g. [ 'k', 'K', KELVIN_SIGN ] */
                    if ((listp = hv_fetch(PL_utf8_foldclosures,
                                    (char *) foldbuf, foldlen, FALSE)))
                    {
@@ -10500,9 +11232,9 @@ parseit:
                            }
                            c = SvUV(*c_p);
 
-                           /* /aa doesn't allow folds between ASCII and
-                               * non-; /l doesn't allow them between above
-                               * and below 256 */
+                           /* /aa doesn't allow folds between ASCII and non-;
+                            * /l doesn't allow them between above and below
+                            * 256 */
                            if ((MORE_ASCII_RESTRICTED
                                 && (isASCII(c) != isASCII(j)))
                                    || (LOC && ((c < 256) != (j < 256))))
@@ -10516,9 +11248,9 @@ parseit:
                                        (U8) c,
                                        &l1_fold_invlist, &unicode_alternate);
                            }
-                               /* It may be that the code point is already
-                                   * in this range or already in the bitmap,
-                                   * in which case we need do nothing */
+                               /* It may be that the code point is already in
+                                * this range or already in the bitmap, in
+                                * which case we need do nothing */
                            else if ((c < start || c > end)
                                        && (c > 255
                                            || ! ANYOF_BITMAP_TEST(ret, c)))
@@ -10544,50 +11276,182 @@ parseit:
        }
     }
 
+    /* And combine the result (if any) with any inversion list from properties.
+     * The lists are kept separate up to now because we don't want to fold the
+     * properties */
+    if (properties) {
+       if (nonbitmap) {
+           _invlist_union(nonbitmap, properties, &nonbitmap);
+           SvREFCNT_dec(properties);
+       }
+       else {
+           nonbitmap = properties;
+       }
+    }
+
+    /* Here, <nonbitmap> contains all the code points we can determine at
+     * compile time that we haven't put into the bitmap.  Go through it, and
+     * for things that belong in the bitmap, put them there, and delete from
+     * <nonbitmap> */
+    if (nonbitmap) {
+
+       /* Above-ASCII code points in /d have to stay in <nonbitmap>, as they
+        * possibly only should match when the target string is UTF-8 */
+       UV max_cp_to_set = (DEPENDS_SEMANTICS) ? 127 : 255;
+
+       /* This gets set if we actually need to modify things */
+       bool change_invlist = FALSE;
+
+       UV start, end;
+
+       /* Start looking through <nonbitmap> */
+       invlist_iterinit(nonbitmap);
+       while (invlist_iternext(nonbitmap, &start, &end)) {
+           UV high;
+           int i;
+
+           /* Quit if are above what we should change */
+           if (start > max_cp_to_set) {
+               break;
+           }
+
+           change_invlist = TRUE;
+
+           /* Set all the bits in the range, up to the max that we are doing */
+           high = (end < max_cp_to_set) ? end : max_cp_to_set;
+           for (i = start; i <= (int) high; i++) {
+               if (! ANYOF_BITMAP_TEST(ret, i)) {
+                   ANYOF_BITMAP_SET(ret, i);
+                   stored++;
+                   prevvalue = value;
+                   value = i;
+               }
+           }
+       }
+
+        /* Done with loop; remove any code points that are in the bitmap from
+         * <nonbitmap> */
+       if (change_invlist) {
+           _invlist_subtract(nonbitmap,
+                             (DEPENDS_SEMANTICS)
+                               ? PL_ASCII
+                               : PL_Latin1,
+                              &nonbitmap);
+       }
+
+       /* If have completely emptied it, remove it completely */
+       if (invlist_len(nonbitmap) == 0) {
+           SvREFCNT_dec(nonbitmap);
+           nonbitmap = NULL;
+       }
+    }
+
     /* Here, we have calculated what code points should be in the character
-     * class.   Now we can see about various optimizations.  Fold calculation
-     * needs to take place before inversion.  Otherwise /[^k]/i would invert to
-     * include K, which under /i would match k. */
+     * class.  <nonbitmap> does not overlap the bitmap except possibly in the
+     * case of DEPENDS rules.
+     *
+     * Now we can see about various optimizations.  Fold calculation (which we
+     * did above) needs to take place before inversion.  Otherwise /[^k]/i
+     * would invert to include K, which under /i would match k, which it
+     * shouldn't. */
 
     /* Optimize inverted simple patterns (e.g. [^a-z]).  Note that we haven't
-     * set the FOLD flag yet, so this this does optimize those.  It doesn't
+     * set the FOLD flag yet, so this does optimize those.  It doesn't
      * optimize locale.  Doing so perhaps could be done as long as there is
      * nothing like \w in it; some thought also would have to be given to the
      * interaction with above 0x100 chars */
-    if (! LOC
-       && (ANYOF_FLAGS(ret) & ANYOF_INVERT)
+    if ((ANYOF_FLAGS(ret) & ANYOF_INVERT)
+        && ! LOC
        && ! unicode_alternate
        /* In case of /d, there are some things that should match only when in
         * not in the bitmap, i.e., they require UTF8 to match.  These are
-        * listed in nonbitmap. */
+        * listed in nonbitmap, but if ANYOF_NONBITMAP_NON_UTF8 is set in this
+        * case, they don't require UTF8, so can invert here */
        && (! nonbitmap
            || ! DEPENDS_SEMANTICS
            || (ANYOF_FLAGS(ret) & ANYOF_NONBITMAP_NON_UTF8))
        && SvCUR(listsv) == initial_listsv_len)
     {
+       int i;
        if (! nonbitmap) {
-           for (value = 0; value < ANYOF_BITMAP_SIZE; ++value)
-               ANYOF_BITMAP(ret)[value] ^= 0xFF;
+           for (i = 0; i < 256; ++i) {
+               if (ANYOF_BITMAP_TEST(ret, i)) {
+                   ANYOF_BITMAP_CLEAR(ret, i);
+               }
+               else {
+                   ANYOF_BITMAP_SET(ret, i);
+                   prevvalue = value;
+                   value = i;
+               }
+           }
            /* The inversion means that everything above 255 is matched */
            ANYOF_FLAGS(ret) |= ANYOF_UNICODE_ALL;
        }
        else {
-           /* Here, also has things outside the bitmap.  Go through each bit
-            * individually and add it to the list to get rid of from those
-            * things not in the bitmap */
-           SV *remove_list = _new_invlist(2);
+           /* Here, also has things outside the bitmap that may overlap with
+            * the bitmap.  We have to sync them up, so that they get inverted
+            * in both places.  Earlier, we removed all overlaps except in the
+            * case of /d rules, so no syncing is needed except for this case
+            */
+           SV *remove_list = NULL;
+
+           if (DEPENDS_SEMANTICS) {
+               UV start, end;
+
+               /* Set the bits that correspond to the ones that aren't in the
+                * bitmap.  Otherwise, when we invert, we'll miss these.
+                * Earlier, we removed from the nonbitmap all code points
+                * < 128, so there is no extra work here */
+               invlist_iterinit(nonbitmap);
+               while (invlist_iternext(nonbitmap, &start, &end)) {
+                   if (start > 255) {  /* The bit map goes to 255 */
+                       break;
+                   }
+                   if (end > 255) {
+                       end = 255;
+                   }
+                   for (i = start; i <= (int) end; ++i) {
+                       ANYOF_BITMAP_SET(ret, i);
+                       prevvalue = value;
+                       value = i;
+                   }
+               }
+           }
+
+           /* Now invert both the bitmap and the nonbitmap.  Anything in the
+            * bitmap has to also be removed from the non-bitmap, but again,
+            * there should not be overlap unless is /d rules. */
            _invlist_invert(nonbitmap);
-           for (value = 0; value < 256; ++value) {
-               if (ANYOF_BITMAP_TEST(ret, value)) {
-                   ANYOF_BITMAP_CLEAR(ret, value);
-                   remove_list = add_cp_to_invlist(remove_list, value);
+
+           for (i = 0; i < 256; ++i) {
+               if (ANYOF_BITMAP_TEST(ret, i)) {
+                   ANYOF_BITMAP_CLEAR(ret, i);
+                   if (DEPENDS_SEMANTICS) {
+                       if (! remove_list) {
+                           remove_list = _new_invlist(2);
+                       }
+                       remove_list = add_cp_to_invlist(remove_list, i);
+                   }
                }
                else {
-                   ANYOF_BITMAP_SET(ret, value);
+                   ANYOF_BITMAP_SET(ret, i);
+                   prevvalue = value;
+                   value = i;
+               }
+           }
+
+           /* And do the removal */
+           if (DEPENDS_SEMANTICS) {
+               if (remove_list) {
+                   _invlist_subtract(nonbitmap, remove_list, &nonbitmap);
+                   SvREFCNT_dec(remove_list);
                }
            }
-           _invlist_subtract(nonbitmap, remove_list, &nonbitmap);
-           SvREFCNT_dec(remove_list);
+           else {
+               /* There is no overlap for non-/d, so just delete anything
+                * below 256 */
+               _invlist_intersection(nonbitmap, PL_AboveLatin1, &nonbitmap);
+           }
        }
 
        stored = 256 - stored;
@@ -10598,8 +11462,15 @@ parseit:
 
     /* Folding in the bitmap is taken care of above, but not for locale (for
      * which we have to wait to see what folding is in effect at runtime), and
-     * for things not in the bitmap.  Set run-time fold flag for these */
-    if (FOLD && (LOC || nonbitmap || unicode_alternate)) {
+     * for some things not in the bitmap (only the upper latin folds in this
+     * case, as all other single-char folding has been set above).  Set
+     * run-time fold flag for these */
+    if (FOLD && (LOC
+               || (DEPENDS_SEMANTICS
+                   && nonbitmap
+                   && ! (ANYOF_FLAGS(ret) & ANYOF_NONBITMAP_NON_UTF8))
+               || unicode_alternate))
+    {
        ANYOF_FLAGS(ret) |= ANYOF_LOC_NONBITMAP_FOLD;
     }
 
@@ -10657,17 +11528,28 @@ parseit:
            else {
                op = EXACT;
            }
-       }   /* else 2 chars in the bit map: the folds of each other */
-       else if (AT_LEAST_UNI_SEMANTICS || !isASCII(value)) {
+       }
+       else {   /* else 2 chars in the bit map: the folds of each other */
+
+           /* Use the folded value, which for the cases where we get here,
+            * is just the lower case of the current one (which may resolve to
+            * itself, or to the other one */
+           value = toLOWER_LATIN1(value);
 
            /* To join adjacent nodes, they must be the exact EXACTish type.
-            * Try to use the most likely type, by using EXACTFU if the regex
-            * calls for them, or is required because the character is
-            * non-ASCII */
-           op = EXACTFU;
-       }
-       else {    /* Otherwise, more likely to be EXACTF type */
-           op = EXACTF;
+            * Try to use the most likely type, by using EXACTFA if possible,
+            * then EXACTFU if the regex calls for it, or is required because
+            * the character is non-ASCII.  (If <value> is ASCII, its fold is
+            * also ASCII for the cases where we get here.) */
+           if (MORE_ASCII_RESTRICTED && isASCII(value)) {
+               op = EXACTFA;
+           }
+           else if (AT_LEAST_UNI_SEMANTICS || !isASCII(value)) {
+               op = EXACTFU;
+           }
+           else {    /* Otherwise, more likely to be EXACTF type */
+               op = EXACTF;
+           }
        }
 
        ret = reg_node(pRExC_state, op);
@@ -10687,40 +11569,50 @@ parseit:
         return ret;
     }
 
-    if (nonbitmap) {
-       UV start, end;
-       invlist_iterinit(nonbitmap);
-       while (invlist_iternext(nonbitmap, &start, &end)) {
-           if (start == end) {
-               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n", start);
-           }
-           else {
-               /* The \t sets the whole range */
-               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\t%04"UVxf"\n",
-                       /* XXX EBCDIC */
-                                  start, end);
-           }
-       }
-       SvREFCNT_dec(nonbitmap);
+    /* If there is a swash and more than one element, we can't use the swash in
+     * the optimization below. */
+    if (swash && element_count > 1) {
+       SvREFCNT_dec(swash);
+       swash = NULL;
     }
-
-    if (SvCUR(listsv) == initial_listsv_len && ! unicode_alternate) {
+    if (! nonbitmap
+       && SvCUR(listsv) == initial_listsv_len
+       && ! unicode_alternate)
+    {
        ARG_SET(ret, ANYOF_NONBITMAP_EMPTY);
        SvREFCNT_dec(listsv);
        SvREFCNT_dec(unicode_alternate);
     }
     else {
-
+       /* av[0] stores the character class description in its textual form:
+        *       used later (regexec.c:Perl_regclass_swash()) to initialize the
+        *       appropriate swash, and is also useful for dumping the regnode.
+        * av[1] if NULL, is a placeholder to later contain the swash computed
+        *       from av[0].  But if no further computation need be done, the
+        *       swash is stored there now.
+        * av[2] stores the multicharacter foldings, used later in
+        *       regexec.c:S_reginclass().
+        * av[3] stores the nonbitmap inversion list for use in addition or
+        *       instead of av[0]; not used if av[1] isn't NULL
+        * av[4] is set if any component of the class is from a user-defined
+        *       property; not used if av[1] isn't NULL */
        AV * const av = newAV();
        SV *rv;
-       /* The 0th element stores the character class description
-        * in its textual form: used later (regexec.c:Perl_regclass_swash())
-        * to initialize the appropriate swash (which gets stored in
-        * the 1st element), and also useful for dumping the regnode.
-        * The 2nd element stores the multicharacter foldings,
-        * used later (regexec.c:S_reginclass()). */
-       av_store(av, 0, listsv);
-       av_store(av, 1, NULL);
+
+       av_store(av, 0, (SvCUR(listsv) == initial_listsv_len)
+                       ? &PL_sv_undef
+                       : listsv);
+       if (swash) {
+           av_store(av, 1, swash);
+           SvREFCNT_dec(nonbitmap);
+       }
+       else {
+           av_store(av, 1, NULL);
+           if (nonbitmap) {
+               av_store(av, 3, nonbitmap);
+               av_store(av, 4, newSVuv(has_user_defined_property));
+           }
+       }
 
         /* Store any computed multi-char folds only if we are allowing
          * them */
@@ -10797,8 +11689,11 @@ S_nextchar(pTHX_ RExC_state_t *pRExC_state)
     PERL_ARGS_ASSERT_NEXTCHAR;
 
     for (;;) {
-       if (*RExC_parse == '(' && RExC_parse[1] == '?' &&
-               RExC_parse[2] == '#') {
+       if (RExC_end - RExC_parse >= 3
+           && *RExC_parse == '('
+           && RExC_parse[1] == '?'
+           && RExC_parse[2] == '#')
+       {
            while (*RExC_parse != ')') {
                if (RExC_parse == RExC_end)
                    FAIL("Sequence (?#... not terminated");
@@ -10840,7 +11735,8 @@ S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
        return(ret);
     }
     if (RExC_emit >= RExC_emit_bound)
-        Perl_croak(aTHX_ "panic: reg_node overrun trying to emit %d", op);
+        Perl_croak(aTHX_ "panic: reg_node overrun trying to emit %d, %p>=%p",
+                  op, RExC_emit, RExC_emit_bound);
 
     NODE_ALIGN_FILL(ret);
     ptr = ret;
@@ -10882,7 +11778,7 @@ S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
           We can't do this:
           
           assert(2==regarglen[op]+1); 
-       
+
           Anything larger than this has to allocate the extra amount.
           If we changed this to be:
           
@@ -10895,7 +11791,8 @@ S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
        return(ret);
     }
     if (RExC_emit >= RExC_emit_bound)
-        Perl_croak(aTHX_ "panic: reg_node overrun trying to emit %d", op);
+        Perl_croak(aTHX_ "panic: reg_node overrun trying to emit %d, %p>=%p",
+                  op, RExC_emit, RExC_emit_bound);
 
     NODE_ALIGN_FILL(ret);
     ptr = ret;
@@ -11106,9 +12003,11 @@ S_regtail_study(pTHX_ RExC_state_t *pRExC_state, regnode *p, const regnode *val,
     for (;;) {
         regnode * const temp = regnext(scan);
 #ifdef EXPERIMENTAL_INPLACESCAN
-        if (PL_regkind[OP(scan)] == EXACT)
-            if (join_exact(pRExC_state,scan,&min,1,val,depth+1))
+        if (PL_regkind[OP(scan)] == EXACT) {
+           bool has_exactf_sharp_s;    /* Unexamined in this routine */
+            if (join_exact(pRExC_state,scan,&min, &has_exactf_sharp_s, 1,val,depth+1))
                 return EXACT;
+       }
 #endif
         if ( exact ) {
             switch (OP(scan)) {
@@ -11116,6 +12015,8 @@ S_regtail_study(pTHX_ RExC_state_t *pRExC_state, regnode *p, const regnode *val,
                 case EXACTF:
                 case EXACTFA:
                 case EXACTFU:
+                case EXACTFU_SS:
+                case EXACTFU_NO_TRIE:
                 case EXACTFL:
                         if( exact == PSEUDO )
                             exact= OP(scan);
@@ -11440,8 +12341,6 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
                           SVfARG((MUTABLE_SV(progi->data->data[ ARG( o ) ]))));
     } else if (k == LOGICAL)
        Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
-    else if (k == FOLDCHAR)
-       Perl_sv_catpvf(aTHX_ sv, "[0x%"UVXf"]", PTR2UV(ARG(o)) );
     else if (k == ANYOF) {
        int i, rangestart = -1;
        const U8 flags = ANYOF_FLAGS(o);
@@ -11488,7 +12387,7 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
        Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
        if (flags & ANYOF_INVERT)
            sv_catpvs(sv, "^");
-       
+
        /* output what the standard cp 0-255 bitmap matches */
        for (i = 0; i <= 256; i++) {
            if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
@@ -11532,67 +12431,86 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
            sv_catpvs(sv, "{outside bitmap}");
 
        if (ANYOF_NONBITMAP(o)) {
-           SV *lv;
+           SV *lv; /* Set if there is something outside the bit map */
            SV * const sw = regclass_swash(prog, o, FALSE, &lv, 0);
-       
-           if (lv) {
+            bool byte_output = FALSE;   /* If something in the bitmap has been
+                                           output */
+
+           if (lv && lv != &PL_sv_undef) {
                if (sw) {
                    U8 s[UTF8_MAXBYTES_CASE+1];
 
-                   for (i = 0; i <= 256; i++) { /* just the first 256 */
+                   for (i = 0; i <= 256; i++) { /* Look at chars in bitmap */
                        uvchr_to_utf8(s, i);
-                       
-                       if (i < 256 && swash_fetch(sw, s, TRUE)) {
+
+                       if (i < 256
+                            && ! ANYOF_BITMAP_TEST(o, i)    /* Don't duplicate
+                                                               things already
+                                                               output as part
+                                                               of the bitmap */
+                            && swash_fetch(sw, s, TRUE))
+                        {
                            if (rangestart == -1)
                                rangestart = i;
                        } else if (rangestart != -1) {
+                            byte_output = TRUE;
                            if (i <= rangestart + 3)
                                for (; rangestart < i; rangestart++) {
-                                   const U8 * const e = uvchr_to_utf8(s,rangestart);
-                                   U8 *p;
-                                   for(p = s; p < e; p++)
-                                       put_byte(sv, *p);
+                                   put_byte(sv, rangestart);
                                }
                            else {
-                               const U8 *e = uvchr_to_utf8(s,rangestart);
-                               U8 *p;
-                               for (p = s; p < e; p++)
-                                   put_byte(sv, *p);
+                               put_byte(sv, rangestart);
                                sv_catpvs(sv, "-");
-                               e = uvchr_to_utf8(s, i-1);
-                               for (p = s; p < e; p++)
-                                   put_byte(sv, *p);
-                               }
-                               rangestart = -1;
+                               put_byte(sv, i-1);
                            }
+                           rangestart = -1;
                        }
-                       
-                   sv_catpvs(sv, "..."); /* et cetera */
+                   }
                }
 
                {
                    char *s = savesvpv(lv);
                    char * const origs = s;
-               
+
                    while (*s && *s != '\n')
                        s++;
-               
+
                    if (*s == '\n') {
                        const char * const t = ++s;
-                       
+
+                        if (byte_output) {
+                            sv_catpvs(sv, " ");
+                        }
+
                        while (*s) {
-                           if (*s == '\n')
+                           if (*s == '\n') {
+
+                                /* Truncate very long output */
+                               if (s - origs > 256) {
+                                   Perl_sv_catpvf(aTHX_ sv,
+                                                  "%.*s...",
+                                                  (int) (s - origs - 1),
+                                                  t);
+                                   goto out_dump;
+                               }
                                *s = ' ';
+                           }
+                           else if (*s == '\t') {
+                               *s = '-';
+                           }
                            s++;
                        }
                        if (s[-1] == ' ')
                            s[-1] = 0;
-                       
+
                        sv_catpv(sv, t);
                    }
-               
+
+               out_dump:
+
                    Safefree(origs);
                }
+               SvREFCNT_dec(lv);
            }
        }
 
@@ -11972,7 +12890,8 @@ Perl_re_dup_guts(pTHX_ const REGEXP *sstr, REGEXP *dstr, CLONE_PARAMS *param)
               1: a buffer in a different thread
               2: something we no longer hold a reference on
               so we need to copy it locally.  */
-           /* Note we need to sue SvCUR() on our mother_re, because it, in
+           /* Note we need to use SvCUR(), rather than
+              SvLEN(), on our mother_re, because it, in
               turn, may well be pointing to its own mother_re.  */
            SvPV_set(dstr, SAVEPVN(SvPVX_const(ret->mother_re),
                                   SvCUR(ret->mother_re)+1));
@@ -12120,7 +13039,7 @@ Perl_regnext(pTHX_ register regnode *p)
 }
 #endif
 
-STATIC void    
+STATIC void
 S_re_croak2(pTHX_ const char* pat1,const char* pat2,...)
 {
     va_list args;
@@ -12297,7 +13216,7 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
                goto after_print;
        } else
            CLEAR_OPTSTART;
-       
+
        regprop(r, sv, node);
        PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
                      (int)(2*indent + 1), "", SvPVX_const(sv));
@@ -12345,7 +13264,7 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
             sv_setpvs(sv, "");
            for (word_idx= 0; word_idx < (I32)trie->wordcount; word_idx++) {
                SV ** const elem_ptr = av_fetch(trie_words,word_idx,0);
-               
+
                 PerlIO_printf(Perl_debug_log, "%*s%s ",
                    (int)(2*(indent+3)), "",
                     elem_ptr ? pv_pretty(sv, SvPV_nolen_const(*elem_ptr), SvCUR(*elem_ptr), 60,