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regcomp.c: Reverse order of setting, for speed
[perl5.git] / regcomp.c
index 021e14e..519186e 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -133,7 +133,6 @@ typedef struct RExC_state_t {
     I32                nestroot;               /* root parens we are in - used by accept */
     I32                extralen;
     I32                seen_zerolen;
-    I32                seen_evals;
     regnode    **open_parens;          /* pointers to open parens */
     regnode    **close_parens;         /* pointers to close parens */
     regnode    *opend;                 /* END node in program */
@@ -159,6 +158,7 @@ typedef struct RExC_state_t {
     char       *starttry;              /* -Dr: where regtry was called. */
 #define RExC_starttry  (pRExC_state->starttry)
 #endif
+    SV         *runtime_code_qr;       /* qr with the runtime code blocks */
 #ifdef DEBUGGING
     const char  *lastparse;
     I32         lastnum;
@@ -193,7 +193,6 @@ typedef struct RExC_state_t {
 #define RExC_nestroot   (pRExC_state->nestroot)
 #define RExC_extralen  (pRExC_state->extralen)
 #define RExC_seen_zerolen      (pRExC_state->seen_zerolen)
-#define RExC_seen_evals        (pRExC_state->seen_evals)
 #define RExC_utf8      (pRExC_state->utf8)
 #define RExC_uni_semantics     (pRExC_state->uni_semantics)
 #define RExC_orig_utf8 (pRExC_state->orig_utf8)
@@ -221,7 +220,7 @@ typedef struct RExC_state_t {
 #define        WORST           0       /* Worst case. */
 #define        HASWIDTH        0x01    /* Known to match non-null strings. */
 
-/* Simple enough to be STAR/PLUS operand, in an EXACT node must be a single
+/* Simple enough to be STAR/PLUS operand; in an EXACT node must be a single
  * character, and if utf8, must be invariant.  Note that this is not the same
  * thing as REGNODE_SIMPLE */
 #define        SIMPLE          0x02
@@ -399,14 +398,18 @@ static const scan_data_t zero_scan_data =
 #define UNI_SEMANTICS (get_regex_charset(RExC_flags) == REGEX_UNICODE_CHARSET)
 #define AT_LEAST_UNI_SEMANTICS (get_regex_charset(RExC_flags) >= REGEX_UNICODE_CHARSET)
 #define ASCII_RESTRICTED (get_regex_charset(RExC_flags) == REGEX_ASCII_RESTRICTED_CHARSET)
-#define MORE_ASCII_RESTRICTED (get_regex_charset(RExC_flags) == REGEX_ASCII_MORE_RESTRICTED_CHARSET)
 #define AT_LEAST_ASCII_RESTRICTED (get_regex_charset(RExC_flags) >= REGEX_ASCII_RESTRICTED_CHARSET)
+#define ASCII_FOLD_RESTRICTED (get_regex_charset(RExC_flags) == REGEX_ASCII_MORE_RESTRICTED_CHARSET)
 
 #define FOLD cBOOL(RExC_flags & RXf_PMf_FOLD)
 
-#define OOB_UNICODE            12345678
 #define OOB_NAMEDCLASS         -1
 
+/* There is no code point that is out-of-bounds, so this is problematic.  But
+ * its only current use is to initialize a variable that is always set before
+ * looked at. */
+#define OOB_UNICODE            0xDEADBEEF
+
 #define CHR_SVLEN(sv) (UTF ? sv_len_utf8(sv) : SvCUR(sv))
 #define CHR_DIST(a,b) (UTF ? utf8_distance(a,b) : a - b)
 
@@ -2631,9 +2634,9 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
  *      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_TRICKYFOLD.
+ * 2)   These sequences require special handling by the trie code, so it
+ *      changes the joined node type to ops for the trie's benefit, those new
+ *      ops being EXACTFU_SS and EXACTFU_TRICKYFOLD.
  * 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"
@@ -3380,7 +3383,6 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                                  * the end pointer. */
                                 if ( !first ) {
                                     first = cur;
-                                    trietype = noper_trietype;
                                    if ( noper_trietype == NOTHING ) {
 #if !defined(DEBUGGING) && !defined(NOJUMPTRIE)
                                        regnode * const noper_next = regnext( noper );
@@ -3388,8 +3390,15 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                                        U8 noper_next_trietype = noper_next_type ? TRIE_TYPE( noper_next_type ) :0;
 #endif
 
-                                        if ( noper_next_trietype )
+                                        if ( noper_next_trietype ) {
                                            trietype = noper_next_trietype;
+                                        } else if (noper_next_type)  {
+                                            /* a NOTHING regop is 1 regop wide. We need at least two
+                                             * for a trie so we can't merge this in */
+                                            first = NULL;
+                                        }
+                                    } else {
+                                        trietype = noper_trietype;
                                     }
                                 } else {
                                     if ( trietype == NOTHING )
@@ -4399,6 +4408,8 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
            data->flags |= (OP(scan) == MEOL
                            ? SF_BEFORE_MEOL
                            : SF_BEFORE_SEOL);
+           SCAN_COMMIT(pRExC_state, data, minlenp);
+
        }
        else if (  PL_regkind[OP(scan)] == BRANCHJ
                 /* Lookbehind, or need to calculate parens/evals/stclass: */
@@ -4962,6 +4973,229 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 rx_flags)
                                NULL, NULL, rx_flags, 0);
 }
 
+/* see if there are any run-time code blocks in the pattern.
+ * False positives are allowed */
+
+static bool
+S_has_runtime_code(pTHX_ RExC_state_t * const pRExC_state, OP *expr,
+                   U32 pm_flags, char *pat, STRLEN plen)
+{
+    int n = 0;
+    STRLEN s;
+
+    /* avoid infinitely recursing when we recompile the pattern parcelled up
+     * as qr'...'. A single constant qr// string can't have have any
+     * run-time component in it, and thus, no runtime code. (A non-qr
+     * string, however, can, e.g. $x =~ '(?{})') */
+    if  ((pm_flags & PMf_IS_QR) && expr && expr->op_type == OP_CONST)
+       return 0;
+
+    for (s = 0; s < plen; s++) {
+       if (n < pRExC_state->num_code_blocks
+           && s == pRExC_state->code_blocks[n].start)
+       {
+           s = pRExC_state->code_blocks[n].end;
+           n++;
+           continue;
+       }
+       /* TODO ideally should handle [..], (#..), /#.../x to reduce false
+        * positives here */
+       if (pat[s] == '(' && pat[s+1] == '?' &&
+           (pat[s+2] == '{' || (pat[s+2] == '?' && pat[s+3] == '{'))
+       )
+           return 1;
+    }
+    return 0;
+}
+
+/* Handle run-time code blocks. We will already have compiled any direct
+ * or indirect literal code blocks. Now, take the pattern 'pat' and make a
+ * copy of it, but with any literal code blocks blanked out and
+ * appropriate chars escaped; then feed it into
+ *
+ *    eval "qr'modified_pattern'"
+ *
+ * For example,
+ *
+ *       a\bc(?{"this was literal"})def'ghi\\jkl(?{"this is runtime"})mno
+ *
+ * becomes
+ *
+ *    qr'a\\bc                       def\'ghi\\\\jkl(?{"this is runtime"})mno'
+ *
+ * After eval_sv()-ing that, grab any new code blocks from the returned qr
+ * and merge them with any code blocks of the original regexp.
+ *
+ * If the pat is non-UTF8, while the evalled qr is UTF8, don't merge;
+ * instead, just save the qr and return FALSE; this tells our caller that
+ * the original pattern needs upgrading to utf8.
+ */
+
+static bool
+S_compile_runtime_code(pTHX_ RExC_state_t * const pRExC_state,
+    char *pat, STRLEN plen)
+{
+    SV *qr;
+
+    GET_RE_DEBUG_FLAGS_DECL;
+
+    if (pRExC_state->runtime_code_qr) {
+       /* this is the second time we've been called; this should
+        * only happen if the main pattern got upgraded to utf8
+        * during compilation; re-use the qr we compiled first time
+        * round (which should be utf8 too)
+        */
+       qr = pRExC_state->runtime_code_qr;
+       pRExC_state->runtime_code_qr = NULL;
+       assert(RExC_utf8 && SvUTF8(qr));
+    }
+    else {
+       int n = 0;
+       STRLEN s;
+       char *p, *newpat;
+       int newlen = plen + 6; /* allow for "qr''x\0" extra chars */
+       SV *sv, *qr_ref;
+       dSP;
+
+       /* determine how many extra chars we need for ' and \ escaping */
+       for (s = 0; s < plen; s++) {
+           if (pat[s] == '\'' || pat[s] == '\\')
+               newlen++;
+       }
+
+       Newx(newpat, newlen, char);
+       p = newpat;
+       *p++ = 'q'; *p++ = 'r'; *p++ = '\'';
+
+       for (s = 0; s < plen; s++) {
+           if (n < pRExC_state->num_code_blocks
+               && s == pRExC_state->code_blocks[n].start)
+           {
+               /* blank out literal code block */
+               assert(pat[s] == '(');
+               while (s <= pRExC_state->code_blocks[n].end) {
+                   *p++ = ' ';
+                   s++;
+               }
+               s--;
+               n++;
+               continue;
+           }
+           if (pat[s] == '\'' || pat[s] == '\\')
+               *p++ = '\\';
+           *p++ = pat[s];
+       }
+       *p++ = '\'';
+       if (pRExC_state->pm_flags & RXf_PMf_EXTENDED)
+           *p++ = 'x';
+       *p++ = '\0';
+       DEBUG_COMPILE_r({
+           PerlIO_printf(Perl_debug_log,
+               "%sre-parsing pattern for runtime code:%s %s\n",
+               PL_colors[4],PL_colors[5],newpat);
+       });
+
+       sv = newSVpvn_flags(newpat, p-newpat-1, RExC_utf8 ? SVf_UTF8 : 0);
+       Safefree(newpat);
+
+       ENTER;
+       SAVETMPS;
+       save_re_context();
+       PUSHSTACKi(PERLSI_REQUIRE);
+       /* this causes the toker to collapse \\ into \ when parsing
+        * qr''; normally only q'' does this. It also alters hints
+        * handling */
+       PL_reg_state.re_reparsing = TRUE;
+       eval_sv(sv, G_SCALAR);
+       SvREFCNT_dec(sv);
+       SPAGAIN;
+       qr_ref = POPs;
+       PUTBACK;
+       if (SvTRUE(ERRSV))
+           Perl_croak(aTHX_ "%s", SvPVx_nolen_const(ERRSV));
+       assert(SvROK(qr_ref));
+       qr = SvRV(qr_ref);
+       assert(SvTYPE(qr) == SVt_REGEXP && RX_ENGINE((REGEXP*)qr)->op_comp);
+       /* the leaving below frees the tmp qr_ref.
+        * Give qr a life of its own */
+       SvREFCNT_inc(qr);
+       POPSTACK;
+       FREETMPS;
+       LEAVE;
+
+    }
+
+    if (!RExC_utf8 && SvUTF8(qr)) {
+       /* first time through; the pattern got upgraded; save the
+        * qr for the next time through */
+       assert(!pRExC_state->runtime_code_qr);
+       pRExC_state->runtime_code_qr = qr;
+       return 0;
+    }
+
+
+    /* extract any code blocks within the returned qr//  */
+
+
+    /* merge the main (r1) and run-time (r2) code blocks into one */
+    {
+       RXi_GET_DECL(((struct regexp*)SvANY(qr)), r2);
+       struct reg_code_block *new_block, *dst;
+       RExC_state_t * const r1 = pRExC_state; /* convenient alias */
+       int i1 = 0, i2 = 0;
+
+       if (!r2->num_code_blocks) /* we guessed wrong */
+           return 1;
+
+       Newx(new_block,
+           r1->num_code_blocks + r2->num_code_blocks,
+           struct reg_code_block);
+       dst = new_block;
+
+       while (    i1 < r1->num_code_blocks
+               || i2 < r2->num_code_blocks)
+       {
+           struct reg_code_block *src;
+           bool is_qr = 0;
+
+           if (i1 == r1->num_code_blocks) {
+               src = &r2->code_blocks[i2++];
+               is_qr = 1;
+           }
+           else if (i2 == r2->num_code_blocks)
+               src = &r1->code_blocks[i1++];
+           else if (  r1->code_blocks[i1].start
+                    < r2->code_blocks[i2].start)
+           {
+               src = &r1->code_blocks[i1++];
+               assert(src->end < r2->code_blocks[i2].start);
+           }
+           else {
+               assert(  r1->code_blocks[i1].start
+                      > r2->code_blocks[i2].start);
+               src = &r2->code_blocks[i2++];
+               is_qr = 1;
+               assert(src->end < r1->code_blocks[i1].start);
+           }
+
+           assert(pat[src->start] == '(');
+           assert(pat[src->end]   == ')');
+           dst->start      = src->start;
+           dst->end        = src->end;
+           dst->block      = src->block;
+           dst->src_regex  = is_qr ? (REGEXP*) SvREFCNT_inc( (SV*) qr)
+                                   : src->src_regex;
+           dst++;
+       }
+       r1->num_code_blocks += r2->num_code_blocks;
+       Safefree(r1->code_blocks);
+       r1->code_blocks = new_block;
+    }
+
+    SvREFCNT_dec(qr);
+    return 1;
+}
+
 
 /*
  * Perl_re_op_compile - the perl internal RE engine's function to compile a
@@ -4990,8 +5224,9 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 rx_flags)
  *
  * orig_rx_flags contains RXf_* flags. See perlreapi.pod for more details.
  *
- * pm_flags contains the PMf_* flags from the calling PMOP. Currently
- * we're only interested in PMf_HAS_CV and PMf_IS_QR.
+ * pm_flags contains the PMf_* flags, typically based on those from the
+ * pm_flags field of the related PMOP. Currently we're only interested in
+ * PMf_HAS_CV, PMf_IS_QR, PMf_USE_RE_EVAL.
  *
  * We can't allocate space until we know how big the compiled form will be,
  * but we can't compile it (and thus know how big it is) until we've got a
@@ -5009,7 +5244,7 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 rx_flags)
 REGEXP *
 Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
                    OP *expr, const regexp_engine* eng, REGEXP *VOL old_re,
-                    int *is_bare_re, U32 orig_rx_flags, U32 pm_flags)
+                    bool *is_bare_re, U32 orig_rx_flags, U32 pm_flags)
 {
     dVAR;
     REGEXP *rx;
@@ -5032,7 +5267,8 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     bool used_setjump = FALSE;
     regex_charset initial_charset = get_regex_charset(orig_rx_flags);
     bool code_is_utf8 = 0;
-
+    bool VOL recompile = 0;
+    bool runtime_code = 0;
     U8 jump_ret = 0;
     dJMPENV;
     scan_data_t data;
@@ -5075,9 +5311,6 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
        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_L1PosixLower = _new_invlist_C_array(L1PosixLower_invlist);
        PL_PosixLower = _new_invlist_C_array(PosixLower_invlist);
 
@@ -5110,7 +5343,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     pRExC_state->num_code_blocks = 0;
 
     if (is_bare_re)
-       *is_bare_re = 0;
+       *is_bare_re = FALSE;
 
     if (expr && (expr->op_type == OP_LIST ||
                (expr->op_type == OP_NULL && expr->op_targ == OP_LIST))) {
@@ -5159,6 +5392,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
            OP *o = NULL;
            int n = 0;
            bool utf8 = 0;
+            STRLEN orig_patlen = 0;
 
            if (pRExC_state->num_code_blocks) {
                o = cLISTOPx(expr)->op_first;
@@ -5200,24 +5434,54 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
                    o = o->op_sibling;;
                }
 
+               if ((SvAMAGIC(pat) || SvAMAGIC(msv)) &&
+                       (sv = amagic_call(pat, msv, concat_amg, AMGf_assign)))
+               {
+                   sv_setsv(pat, sv);
+                   /* overloading involved: all bets are off over literal
+                    * code. Pretend we haven't seen it */
+                   pRExC_state->num_code_blocks -= n;
+                   n = 0;
+                    rx = NULL;
+
+               }
+               else  {
+                    while (SvAMAGIC(msv)
+                            && (sv = AMG_CALLunary(msv, string_amg))
+                            && sv != msv)
+                    {
+                        msv = sv;
+                        SvGETMAGIC(msv);
+                    }
+                    if (SvROK(msv) && SvTYPE(SvRV(msv)) == SVt_REGEXP)
+                        msv = SvRV(msv);
+                    orig_patlen = SvCUR(pat);
+                    sv_catsv_nomg(pat, msv);
+                    rx = msv;
+                    if (code)
+                        pRExC_state->code_blocks[n-1].end = SvCUR(pat)-1;
+                }
+
                /* extract any code blocks within any embedded qr//'s */
-               rx = msv;
-               if (SvROK(rx))
-                   rx = SvRV(rx);
-               if (SvTYPE(rx) == SVt_REGEXP
+               if (rx && SvTYPE(rx) == SVt_REGEXP
                    && RX_ENGINE((REGEXP*)rx)->op_comp)
                {
 
                    RXi_GET_DECL(((struct regexp*)SvANY(rx)), ri);
                    if (ri->num_code_blocks) {
                        int i;
+                       /* the presence of an embedded qr// with code means
+                        * we should always recompile: the text of the
+                        * qr// may not have changed, but it may be a
+                        * different closure than last time */
+                       recompile = 1;
                        Renew(pRExC_state->code_blocks,
                            pRExC_state->num_code_blocks + ri->num_code_blocks,
                            struct reg_code_block);
                        pRExC_state->num_code_blocks += ri->num_code_blocks;
                        for (i=0; i < ri->num_code_blocks; i++) {
                            struct reg_code_block *src, *dst;
-                           STRLEN offset =  SvCUR(pat)
+                           STRLEN offset =  orig_patlen
                                + ((struct regexp *)SvANY(rx))->pre_prefix;
                            assert(n < pRExC_state->num_code_blocks);
                            src = &ri->code_blocks[i];
@@ -5233,27 +5497,20 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
                        }
                    }
                }
-
-               if ((SvAMAGIC(pat) || SvAMAGIC(msv)) &&
-                       (sv = amagic_call(pat, msv, concat_amg, AMGf_assign)))
-               {
-                   sv_setsv(pat, sv);
-                   /* overloading involved: all bets are off over literal
-                    * code. Pretend we haven't seen it */
-                   pRExC_state->num_code_blocks -= n;
-                   n = 0;
-
-               }
-               else {
-                   sv_catsv_nomg(pat, msv);
-                   if (code)
-                       pRExC_state->code_blocks[n-1].end = SvCUR(pat)-1;
-               }
            }
            SvSETMAGIC(pat);
        }
-       else
+       else {
+            SV *sv;
            pat = *patternp;
+            while (SvAMAGIC(pat)
+                    && (sv = AMG_CALLunary(pat, string_amg))
+                    && sv != pat)
+            {
+                pat = sv;
+                SvGETMAGIC(pat);
+            }
+        }
 
        /* handle bare regex: foo =~ $re */
        {
@@ -5262,7 +5519,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
                re = SvRV(re);
            if (SvTYPE(re) == SVt_REGEXP) {
                if (is_bare_re)
-                   *is_bare_re = 1;
+                   *is_bare_re = TRUE;
                SvREFCNT_inc(re);
                Safefree(pRExC_state->code_blocks);
                return (REGEXP*)re;
@@ -5330,6 +5587,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     RExC_utf8 = RExC_orig_utf8 = (plen == 0 || IN_BYTES) ? 0 : SvUTF8(pat);
     RExC_uni_semantics = 0;
     RExC_contains_locale = 0;
+    pRExC_state->runtime_code_qr = NULL;
 
     /****************** LONG JUMP TARGET HERE***********************/
     /* Longjmp back to here if have to switch in midstream to utf8 */
@@ -5417,18 +5675,32 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     /* return old regex if pattern hasn't changed */
 
     if (   old_re
+        && !recompile
        && !!RX_UTF8(old_re) == !!RExC_utf8
        && RX_PRECOMP(old_re)
        && RX_PRELEN(old_re) == plen
        && memEQ(RX_PRECOMP(old_re), exp, plen))
     {
-       ReREFCNT_inc(old_re);
-       if (used_setjump) {
-           JMPENV_POP;
+       /* with runtime code, always recompile */
+       runtime_code = S_has_runtime_code(aTHX_ pRExC_state, expr, pm_flags,
+                                           exp, plen);
+       if (!runtime_code) {
+           ReREFCNT_inc(old_re);
+           if (used_setjump) {
+               JMPENV_POP;
+           }
+           Safefree(pRExC_state->code_blocks);
+           return old_re;
        }
-       Safefree(pRExC_state->code_blocks);
-       return old_re;
     }
+    else if ((pm_flags & PMf_USE_RE_EVAL)
+               /* this second condition covers the non-regex literal case,
+                * i.e.  $foo =~ '(?{})'. */
+               || ( !PL_reg_state.re_reparsing && IN_PERL_COMPILETIME
+                   && (PL_hints & HINT_RE_EVAL))
+    )
+       runtime_code = S_has_runtime_code(aTHX_ pRExC_state, expr, pm_flags,
+                           exp, plen);
 
 #ifdef TRIE_STUDY_OPT
     restudied = 0;
@@ -5449,12 +5721,24 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     RExC_precomp = exp;
     RExC_flags = rx_flags;
     RExC_pm_flags = pm_flags;
+
+    if (runtime_code) {
+       if (PL_tainting && PL_tainted)
+           Perl_croak(aTHX_ "Eval-group in insecure regular expression");
+
+       if (!S_compile_runtime_code(aTHX_ pRExC_state, exp, plen)) {
+           /* whoops, we have a non-utf8 pattern, whilst run-time code
+            * got compiled as utf8. Try again with a utf8 pattern */
+            JMPENV_JUMP(UTF8_LONGJMP);
+       }
+    }
+    assert(!pRExC_state->runtime_code_qr);
+
     RExC_sawback = 0;
 
     RExC_seen = 0;
     RExC_in_lookbehind = 0;
     RExC_seen_zerolen = *exp == '^' ? -1 : 0;
-    RExC_seen_evals = 0;
     RExC_extralen = 0;
     RExC_override_recoding = 0;
 
@@ -5483,7 +5767,11 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
        * 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;
        Safefree(pRExC_state->code_blocks);
@@ -5651,8 +5939,6 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     RExC_emit_bound = ri->program + RExC_size + 1;
     pRExC_state->code_index = 0;
 
-    /* Store the count of eval-groups for security checks: */
-    RExC_rx->seen_evals = RExC_seen_evals;
     REGC((U8)REG_MAGIC, (char*) RExC_emit++);
     if (reg(pRExC_state, 0, &flags,1) == NULL) {
        ReREFCNT_dec(rx);   
@@ -5805,7 +6091,7 @@ reStudy:
        else if ((!sawopen || !RExC_sawback) &&
            (OP(first) == STAR &&
            PL_regkind[OP(NEXTOPER(first))] == REG_ANY) &&
-           !(r->extflags & RXf_ANCH) && !(RExC_seen & REG_SEEN_EVAL))
+           !(r->extflags & RXf_ANCH) && !pRExC_state->num_code_blocks)
        {
            /* turn .* into ^.* with an implied $*=1 */
            const int type =
@@ -5818,7 +6104,7 @@ reStudy:
            goto again;
        }
        if (sawplus && !sawlookahead && (!sawopen || !RExC_sawback)
-           && !(RExC_seen & REG_SEEN_EVAL)) /* May examine pos and $& */
+           && !pRExC_state->num_code_blocks) /* May examine pos and $& */
            /* x+ must match at the 1st pos of run of x's */
            r->intflags |= PREGf_SKIP;
 
@@ -6091,7 +6377,7 @@ reStudy:
        r->extflags |= RXf_GPOS_SEEN;
     if (RExC_seen & REG_SEEN_LOOKBEHIND)
        r->extflags |= RXf_LOOKBEHIND_SEEN;
-    if (RExC_seen & REG_SEEN_EVAL)
+    if (pRExC_state->num_code_blocks)
        r->extflags |= RXf_EVAL_SEEN;
     if (RExC_seen & REG_SEEN_CANY)
        r->extflags |= RXf_CANY_SEEN;
@@ -6099,6 +6385,8 @@ reStudy:
        r->intflags |= PREGf_VERBARG_SEEN;
     if (RExC_seen & REG_SEEN_CUTGROUP)
        r->intflags |= PREGf_CUTGROUP_SEEN;
+    if (pm_flags & PMf_USE_RE_EVAL)
+       r->intflags |= PREGf_USE_RE_EVAL;
     if (RExC_paren_names)
         RXp_PAREN_NAMES(r) = MUTABLE_HV(SvREFCNT_inc(RExC_paren_names));
     else
@@ -6586,8 +6874,10 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags)
            do {
                RExC_parse++;
            } while (isALNUM(*RExC_parse));
+    } else {
+       RExC_parse++; /* so the <- from the vFAIL is after the offending character */
+        vFAIL("Group name must start with a non-digit word character");
     }
-
     if ( flags ) {
         SV* sv_name
            = newSVpvn_flags(name_start, (int)(RExC_parse - name_start),
@@ -6611,7 +6901,7 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags)
             Perl_croak(aTHX_ "panic: bad flag %lx in reg_scan_name",
                       (unsigned long) flags);
         }
-        /* NOT REACHED */
+        assert(0); /* NOT REACHED */
     }
     return NULL;
 }
@@ -7144,7 +7434,6 @@ Perl__invlist_populate_swatch(pTHX_ SV* const invlist, const UV start, const UV
     return;
 }
 
-
 void
 Perl__invlist_union_maybe_complement_2nd(pTHX_ SV* const a, SV* const b, bool complement_b, SV** output)
 {
@@ -7806,6 +8095,36 @@ S_invlist_iternext(pTHX_ SV* invlist, UV* start, UV* end)
     return TRUE;
 }
 
+PERL_STATIC_INLINE UV
+S_invlist_highest(pTHX_ SV* const invlist)
+{
+    /* Returns the highest code point that matches an inversion list.  This API
+     * has an ambiguity, as it returns 0 under either the highest is actually
+     * 0, or if the list is empty.  If this distinction matters to you, check
+     * for emptiness before calling this function */
+
+    UV len = invlist_len(invlist);
+    UV *array;
+
+    PERL_ARGS_ASSERT_INVLIST_HIGHEST;
+
+    if (len == 0) {
+       return 0;
+    }
+
+    array = invlist_array(invlist);
+
+    /* The last element in the array in the inversion list always starts a
+     * range that goes to infinity.  That range may be for code points that are
+     * matched in the inversion list, or it may be for ones that aren't
+     * matched.  In the latter case, the highest code point in the set is one
+     * less than the beginning of this range; otherwise it is the final element
+     * of this range: infinity */
+    return (ELEMENT_RANGE_MATCHES_INVLIST(len - 1))
+           ? UV_MAX
+           : array[len - 1] - 1;
+}
+
 #ifndef PERL_IN_XSUB_RE
 SV *
 Perl__invlist_contents(pTHX_ SV* const invlist)
@@ -8068,7 +8387,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                    ret = reganode(pRExC_state,
                                   ((! FOLD)
                                     ? NREF
-                                    : (MORE_ASCII_RESTRICTED)
+                                    : (ASCII_FOLD_RESTRICTED)
                                       ? NREFFA
                                        : (AT_LEAST_UNI_SEMANTICS)
                                          ? NREFFU
@@ -8225,7 +8544,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                     num = sv_dat ? *((I32 *)SvPVX(sv_dat)) : 0;
                 }
                 goto gen_recurse_regop;
-                /* NOT REACHED */
+                assert(0); /* NOT REACHED */
             case '+':
                 if (!(RExC_parse[0] >= '1' && RExC_parse[0] <= '9')) {
                     RExC_parse++;
@@ -8295,7 +8614,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                 nextchar(pRExC_state);
                 return ret;
             } /* named and numeric backreferences */
-            /* NOT REACHED */
+            assert(0); /* NOT REACHED */
 
            case '?':           /* (??...) */
                is_logical = 1;
@@ -8309,98 +8628,51 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                /* FALL THROUGH */
            case '{':           /* (?{...}) */
            {
-               I32 count = 1;
                U32 n = 0;
-               char c;
-               char *s = RExC_parse;
+               struct reg_code_block *cb;
 
                RExC_seen_zerolen++;
-               RExC_seen |= REG_SEEN_EVAL;
 
-               if (   pRExC_state->num_code_blocks
-                   && pRExC_state->code_index < pRExC_state->num_code_blocks
-                   && pRExC_state->code_blocks[pRExC_state->code_index].start
-                       == (STRLEN)((RExC_parse -3 - (is_logical ? 1 : 0))
+               if (   !pRExC_state->num_code_blocks
+                   || pRExC_state->code_index >= pRExC_state->num_code_blocks
+                   || pRExC_state->code_blocks[pRExC_state->code_index].start
+                       != (STRLEN)((RExC_parse -3 - (is_logical ? 1 : 0))
                            - RExC_start)
                ) {
-                   /* this is a pre-compiled literal (?{}) */
-                   struct reg_code_block *cb =
-                       &pRExC_state->code_blocks[pRExC_state->code_index];
-                   RExC_parse = RExC_start + cb->end;
-                   if (SIZE_ONLY)
-                       RExC_seen_evals++;
-                   else {
-                       OP *o = cb->block;
-                       if (cb->src_regex) {
-                           n = add_data(pRExC_state, 2, "rl");
-                           RExC_rxi->data->data[n] =
-                               (void*)SvREFCNT_inc((SV*)cb->src_regex);
-                       RExC_rxi->data->data[n+1] = (void*)o->op_next;
-                       }
-                       else {
-                           n = add_data(pRExC_state, 1,
-                                  (RExC_pm_flags & PMf_HAS_CV) ? "L" : "l");
-                           RExC_rxi->data->data[n] = (void*)o->op_next;
-                       }
-                   }
-                   pRExC_state->code_index++;
+                   if (RExC_pm_flags & PMf_USE_RE_EVAL)
+                       FAIL("panic: Sequence (?{...}): no code block found\n");
+                   FAIL("Eval-group not allowed at runtime, use re 'eval'");
                }
-               else {
-                   while (count && (c = *RExC_parse)) {
-                       if (c == '\\') {
-                           if (RExC_parse[1])
-                               RExC_parse++;
-                       }
-                       else if (c == '{')
-                           count++;
-                       else if (c == '}')
-                           count--;
-                       RExC_parse++;
-                   }
-                   if (*RExC_parse != ')') {
-                       RExC_parse = s;
-                       vFAIL("Sequence (?{...}) not terminated or not {}-balanced");
-                   }
-                   if (!SIZE_ONLY) {
-                       PAD *pad;
-                       OP_4tree *sop, *rop;
-                       SV * const sv = newSVpvn(s, RExC_parse - 1 - s);
-
-                       ENTER;
-                       Perl_save_re_context(aTHX);
-                       rop = Perl_sv_compile_2op_is_broken(aTHX_ sv, &sop, "re", &pad);
-                       sop->op_private |= OPpREFCOUNTED;
-                       /* re_dup will OpREFCNT_inc */
-                       OpREFCNT_set(sop, 1);
-                       LEAVE;
-
-                       n = add_data(pRExC_state, 3, "nop");
-                       RExC_rxi->data->data[n] = (void*)rop;
-                       RExC_rxi->data->data[n+1] = (void*)sop;
-                       RExC_rxi->data->data[n+2] = (void*)pad;
-                       SvREFCNT_dec(sv);
+               /* this is a pre-compiled code block (?{...}) */
+               cb = &pRExC_state->code_blocks[pRExC_state->code_index];
+               RExC_parse = RExC_start + cb->end;
+               if (!SIZE_ONLY) {
+                   OP *o = cb->block;
+                   if (cb->src_regex) {
+                       n = add_data(pRExC_state, 2, "rl");
+                       RExC_rxi->data->data[n] =
+                           (void*)SvREFCNT_inc((SV*)cb->src_regex);
+                       RExC_rxi->data->data[n+1] = (void*)o;
                    }
-                   else {                                              /* First pass */
-                       if (PL_reginterp_cnt < ++RExC_seen_evals
-                           && IN_PERL_RUNTIME)
-                           /* No compiled RE interpolated, has runtime
-                              components ===> unsafe.  */
-                           FAIL("Eval-group not allowed at runtime, use re 'eval'");
-                       if (PL_tainting && PL_tainted)
-                           FAIL("Eval-group in insecure regular expression");
-    #if PERL_VERSION > 8
-                       if (IN_PERL_COMPILETIME)
-                           PL_cv_has_eval = 1;
-    #endif
+                   else {
+                       n = add_data(pRExC_state, 1,
+                              (RExC_pm_flags & PMf_HAS_CV) ? "L" : "l");
+                       RExC_rxi->data->data[n] = (void*)o;
                    }
                }
+               pRExC_state->code_index++;
                nextchar(pRExC_state);
 
                if (is_logical) {
+                    regnode *eval;
                    ret = reg_node(pRExC_state, LOGICAL);
-                   if (!SIZE_ONLY)
+                    eval = reganode(pRExC_state, EVAL, n);
+                   if (!SIZE_ONLY) {
                        ret->flags = 2;
-                    REGTAIL(pRExC_state, ret, reganode(pRExC_state, EVAL, n));
+                        /* for later propagation into (??{}) return value */
+                        eval->flags = (U8) (RExC_flags & RXf_PMf_COMPILETIME);
+                    }
+                    REGTAIL(pRExC_state, ret, eval);
                     /* deal with the length of this later - MJD */
                    return ret;
                }
@@ -8930,7 +9202,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
        }
        else
            FAIL("Junk on end of regexp");      /* "Can't happen". */
-       /* NOTREACHED */
+       assert(0); /* NOTREACHED */
     }
 
     if (RExC_in_lookbehind) {
@@ -9463,6 +9735,81 @@ S_reg_recode(pTHX_ const char value, SV **encp)
     return uv;
 }
 
+PERL_STATIC_INLINE U8
+S_compute_EXACTish(pTHX_ RExC_state_t *pRExC_state)
+{
+    U8 op;
+
+    PERL_ARGS_ASSERT_COMPUTE_EXACTISH;
+
+    if (! FOLD) {
+        return EXACT;
+    }
+
+    op = get_regex_charset(RExC_flags);
+    if (op >= REGEX_ASCII_RESTRICTED_CHARSET) {
+        op--; /* /a is same as /u, and map /aa's offset to what /a's would have
+                 been, so there is no hole */
+    }
+
+    return op + EXACTF;
+}
+
+PERL_STATIC_INLINE void
+S_alloc_maybe_populate_EXACT(pTHX_ RExC_state_t *pRExC_state, regnode *node, STRLEN len, UV code_point)
+{
+    /* This knows the details about sizing an EXACTish node, and potentially
+     * populating it with a single character.  If <len> is non-zero, it assumes
+     * that the node has already been populated, and just does the sizing,
+     * ignoring <code_point>.  Otherwise it looks at <code_point> and
+     * calculates what <len> should be.  In pass 1, it sizes the node
+     * appropriately.  In pass 2, it additionally will populate the node's
+     * STRING with <code_point>, if <len> is 0.
+     *
+     * It knows that under FOLD, UTF characters and the Latin Sharp S must be
+     * folded (the latter only when the rules indicate it can match 'ss') */
+
+    bool len_passed_in = cBOOL(len != 0);
+    U8 character[UTF8_MAXBYTES_CASE+1];
+
+    PERL_ARGS_ASSERT_ALLOC_MAYBE_POPULATE_EXACT;
+
+    if (! len_passed_in) {
+        if (UTF) {
+            if (FOLD) {
+                to_uni_fold(NATIVE_TO_UNI(code_point), character, &len);
+            }
+            else {
+                uvchr_to_utf8( character, code_point);
+                len = UTF8SKIP(character);
+            }
+        }
+        else if (! FOLD
+                 || code_point != LATIN_SMALL_LETTER_SHARP_S
+                 || ASCII_FOLD_RESTRICTED
+                 || ! AT_LEAST_UNI_SEMANTICS)
+        {
+            *character = (U8) code_point;
+            len = 1;
+        }
+        else {
+            *character = 's';
+            *(character + 1) = 's';
+            len = 2;
+        }
+    }
+
+    if (SIZE_ONLY) {
+        RExC_size += STR_SZ(len);
+    }
+    else {
+        RExC_emit += STR_SZ(len);
+        STR_LEN(node) = len;
+        if (! len_passed_in) {
+            Copy((char *) character, STRING(node), len, char);
+        }
+    }
+}
 
 /*
  - regatom - the lowest level
@@ -9479,8 +9826,46 @@ S_reg_recode(pTHX_ const char value, SV **encp)
    sequence, we return.
 
    Note: we have to be careful with escapes, as they can be both literal
-   and special, and in the case of \10 and friends can either, depending
-   on context. Specifically there are two separate switches for handling
+   and special, and in the case of \10 and friends, context determines which.
+
+   A summary of the code structure is:
+
+   switch (first_byte) {
+       cases for each special:
+           handle this special;
+           break;
+       case '\\':
+           switch (2nd byte) {
+               cases for each unambiguous special:
+                   handle this special;
+                   break;
+               cases for each ambigous special/literal:
+                   disambiguate;
+                   if (special)  handle here
+                   else goto defchar;
+               default: // unambiguously literal:
+                   goto defchar;
+           }
+       default:  // is a literal char
+           // FALL THROUGH
+       defchar:
+           create EXACTish node for literal;
+           while (more input and node isn't full) {
+               switch (input_byte) {
+                  cases for each special;
+                       make sure parse pointer is set so that the next call to
+                           regatom will see this special first
+                       goto loopdone; // EXACTish node terminated by prev. char
+                  default:
+                      append char to EXACTISH node;
+               }
+               get next input byte;
+           }
+        loopdone:
+   }
+   return the generated node;
+
+   Specifically there are two separate switches for handling
    escape sequences, with the one for handling literal escapes requiring
    a dummy entry for all of the special escapes that are actually handled
    by the other.
@@ -9634,43 +10019,17 @@ tryagain:
            *flagp |= HASWIDTH;
            goto finish_meta_pat;
        case 'w':
-           switch (get_regex_charset(RExC_flags)) {
-               case REGEX_LOCALE_CHARSET:
-                   op = ALNUML;
-                   break;
-               case REGEX_UNICODE_CHARSET:
-                   op = ALNUMU;
-                   break;
-               case REGEX_ASCII_RESTRICTED_CHARSET:
-               case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
-                   op = ALNUMA;
-                   break;
-               case REGEX_DEPENDS_CHARSET:
-                   op = ALNUM;
-                   break;
-               default:
-                   goto bad_charset;
+           op = ALNUM + get_regex_charset(RExC_flags);
+            if (op > ALNUMA) {  /* /aa is same as /a */
+                op = ALNUMA;
             }
            ret = reg_node(pRExC_state, op);
            *flagp |= HASWIDTH|SIMPLE;
            goto finish_meta_pat;
        case 'W':
-           switch (get_regex_charset(RExC_flags)) {
-               case REGEX_LOCALE_CHARSET:
-                   op = NALNUML;
-                   break;
-               case REGEX_UNICODE_CHARSET:
-                   op = NALNUMU;
-                   break;
-               case REGEX_ASCII_RESTRICTED_CHARSET:
-               case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
-                   op = NALNUMA;
-                   break;
-               case REGEX_DEPENDS_CHARSET:
-                   op = NALNUM;
-                   break;
-               default:
-                   goto bad_charset;
+           op = NALNUM + get_regex_charset(RExC_flags);
+            if (op > NALNUMA) { /* /aa is same as /a */
+                op = NALNUMA;
             }
            ret = reg_node(pRExC_state, op);
            *flagp |= HASWIDTH|SIMPLE;
@@ -9678,22 +10037,9 @@ tryagain:
        case 'b':
            RExC_seen_zerolen++;
            RExC_seen |= REG_SEEN_LOOKBEHIND;
-           switch (get_regex_charset(RExC_flags)) {
-               case REGEX_LOCALE_CHARSET:
-                   op = BOUNDL;
-                   break;
-               case REGEX_UNICODE_CHARSET:
-                   op = BOUNDU;
-                   break;
-               case REGEX_ASCII_RESTRICTED_CHARSET:
-               case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
-                   op = BOUNDA;
-                   break;
-               case REGEX_DEPENDS_CHARSET:
-                   op = BOUND;
-                   break;
-               default:
-                   goto bad_charset;
+           op = BOUND + get_regex_charset(RExC_flags);
+            if (op > BOUNDA) {  /* /aa is same as /a */
+                op = BOUNDA;
             }
            ret = reg_node(pRExC_state, op);
            FLAGS(ret) = get_regex_charset(RExC_flags);
@@ -9702,103 +10048,45 @@ tryagain:
        case 'B':
            RExC_seen_zerolen++;
            RExC_seen |= REG_SEEN_LOOKBEHIND;
-           switch (get_regex_charset(RExC_flags)) {
-               case REGEX_LOCALE_CHARSET:
-                   op = NBOUNDL;
-                   break;
-               case REGEX_UNICODE_CHARSET:
-                   op = NBOUNDU;
-                   break;
-               case REGEX_ASCII_RESTRICTED_CHARSET:
-               case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
-                   op = NBOUNDA;
-                   break;
-               case REGEX_DEPENDS_CHARSET:
-                   op = NBOUND;
-                   break;
-               default:
-                   goto bad_charset;
+           op = NBOUND + get_regex_charset(RExC_flags);
+            if (op > NBOUNDA) { /* /aa is same as /a */
+                op = NBOUNDA;
             }
            ret = reg_node(pRExC_state, op);
            FLAGS(ret) = get_regex_charset(RExC_flags);
            *flagp |= SIMPLE;
            goto finish_meta_pat;
        case 's':
-           switch (get_regex_charset(RExC_flags)) {
-               case REGEX_LOCALE_CHARSET:
-                   op = SPACEL;
-                   break;
-               case REGEX_UNICODE_CHARSET:
-                   op = SPACEU;
-                   break;
-               case REGEX_ASCII_RESTRICTED_CHARSET:
-               case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
-                   op = SPACEA;
-                   break;
-               case REGEX_DEPENDS_CHARSET:
-                   op = SPACE;
-                   break;
-               default:
-                   goto bad_charset;
+           op = SPACE + get_regex_charset(RExC_flags);
+            if (op > SPACEA) {  /* /aa is same as /a */
+                op = SPACEA;
             }
            ret = reg_node(pRExC_state, op);
            *flagp |= HASWIDTH|SIMPLE;
            goto finish_meta_pat;
        case 'S':
-           switch (get_regex_charset(RExC_flags)) {
-               case REGEX_LOCALE_CHARSET:
-                   op = NSPACEL;
-                   break;
-               case REGEX_UNICODE_CHARSET:
-                   op = NSPACEU;
-                   break;
-               case REGEX_ASCII_RESTRICTED_CHARSET:
-               case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
-                   op = NSPACEA;
-                   break;
-               case REGEX_DEPENDS_CHARSET:
-                   op = NSPACE;
-                   break;
-               default:
-                   goto bad_charset;
-            }
-           ret = reg_node(pRExC_state, op);
-           *flagp |= HASWIDTH|SIMPLE;
-           goto finish_meta_pat;
-       case 'd':
-           switch (get_regex_charset(RExC_flags)) {
-               case REGEX_LOCALE_CHARSET:
-                   op = DIGITL;
-                   break;
-               case REGEX_ASCII_RESTRICTED_CHARSET:
-               case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
-                   op = DIGITA;
-                   break;
-               case REGEX_DEPENDS_CHARSET: /* No difference between these */
-               case REGEX_UNICODE_CHARSET:
-                   op = DIGIT;
-                   break;
-               default:
-                   goto bad_charset;
+           op = NSPACE + get_regex_charset(RExC_flags);
+            if (op > NSPACEA) { /* /aa is same as /a */
+                op = NSPACEA;
             }
            ret = reg_node(pRExC_state, op);
            *flagp |= HASWIDTH|SIMPLE;
            goto finish_meta_pat;
        case 'D':
-           switch (get_regex_charset(RExC_flags)) {
-               case REGEX_LOCALE_CHARSET:
-                   op = NDIGITL;
-                   break;
-               case REGEX_ASCII_RESTRICTED_CHARSET:
-               case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
-                   op = NDIGITA;
-                   break;
-               case REGEX_DEPENDS_CHARSET: /* No difference between these */
-               case REGEX_UNICODE_CHARSET:
-                   op = NDIGIT;
-                   break;
-               default:
-                   goto bad_charset;
+            op = NDIGIT;
+            goto join_D_and_d;
+       case 'd':
+            op = DIGIT;
+        join_D_and_d:
+            {
+                U8 offset = get_regex_charset(RExC_flags);
+                if (offset == REGEX_UNICODE_CHARSET) {
+                    offset = REGEX_DEPENDS_CHARSET;
+                }
+                else if (offset == REGEX_ASCII_MORE_RESTRICTED_CHARSET) {
+                    offset = REGEX_ASCII_RESTRICTED_CHARSET;
+                }
+                op += offset;
             }
            ret = reg_node(pRExC_state, op);
            *flagp |= HASWIDTH|SIMPLE;
@@ -9899,7 +10187,7 @@ tryagain:
                 ret = reganode(pRExC_state,
                                ((! FOLD)
                                  ? NREF
-                                : (MORE_ASCII_RESTRICTED)
+                                : (ASCII_FOLD_RESTRICTED)
                                   ? NREFFA
                                    : (AT_LEAST_UNI_SEMANTICS)
                                      ? NREFFU
@@ -9949,6 +10237,7 @@ tryagain:
                         vFAIL("Reference to nonexistent or unclosed group");
                 }
                if (!isg && num > 9 && num >= RExC_npar)
+                    /* Probably a character specified in octal, e.g. \35 */
                    goto defchar;
                else {
                    char * const parse_start = RExC_parse - 1; /* MJD */
@@ -9969,7 +10258,7 @@ tryagain:
                    ret = reganode(pRExC_state,
                                   ((! FOLD)
                                     ? REF
-                                    : (MORE_ASCII_RESTRICTED)
+                                    : (ASCII_FOLD_RESTRICTED)
                                       ? REFFA
                                        : (AT_LEAST_UNI_SEMANTICS)
                                          ? REFFU
@@ -10026,14 +10315,7 @@ tryagain:
            bool is_exactfu_sharp_s;
 
            ender = 0;
-            node_type = ((! FOLD) ? EXACT
-                       : (LOC)
-                         ? EXACTFL
-                         : (MORE_ASCII_RESTRICTED)
-                           ? EXACTFA
-                           : (AT_LEAST_UNI_SEMANTICS)
-                             ? EXACTFU
-                             : EXACTF);
+            node_type = compute_EXACTish(pRExC_state);
            ret = reg_node(pRExC_state, node_type);
            s = STRING(ret);
 
@@ -10163,38 +10445,39 @@ tryagain:
                            break;
                        }
                    case 'x':
-                       if (*++p == '{') {
-                           char* const e = strchr(p, '}');
+                       {
+                           STRLEN brace_len = len;
+                           UV result;
+                           const char* error_msg;
 
-                           if (!e) {
-                               RExC_parse = p + 1;
-                               vFAIL("Missing right brace on \\x{}");
+                           bool valid = grok_bslash_x(p,
+                                                      &result,
+                                                      &brace_len,
+                                                      &error_msg,
+                                                      1);
+                           p += brace_len;
+                           if (! valid) {
+                               RExC_parse = p; /* going to die anyway; point
+                                                  to exact spot of failure */
+                               vFAIL(error_msg);
                            }
                            else {
-                                I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
-                                    | PERL_SCAN_DISALLOW_PREFIX;
-                                STRLEN numlen = e - p - 1;
-                               ender = grok_hex(p + 1, &numlen, &flags, NULL);
-                               if (ender > 0xff)
-                                   REQUIRE_UTF8;
-                               p = e + 1;
+                               ender = result;
                            }
+                           if (PL_encoding && ender < 0x100) {
+                               goto recode_encoding;
+                           }
+                           if (ender > 0xff) {
+                               REQUIRE_UTF8;
+                           }
+                           break;
                        }
-                       else {
-                            I32 flags = PERL_SCAN_DISALLOW_PREFIX;
-                           STRLEN numlen = 2;
-                           ender = grok_hex(p, &numlen, &flags, NULL);
-                           p += numlen;
-                       }
-                       if (PL_encoding && ender < 0x100)
-                           goto recode_encoding;
-                       break;
                    case 'c':
                        p++;
                        ender = grok_bslash_c(*p++, UTF, SIZE_ONLY);
                        break;
                    case '0': case '1': case '2': case '3':case '4':
-                   case '5': case '6': case '7': case '8':case '9':
+                   case '5': case '6': case '7':
                        if (*p == '0' ||
                            (isDIGIT(p[1]) && atoi(p) >= RExC_npar))
                        {
@@ -10227,7 +10510,7 @@ tryagain:
                            FAIL("Trailing \\");
                        /* FALL THROUGH */
                    default:
-                       if (!SIZE_ONLY&& isALPHA(*p)) {
+                       if (!SIZE_ONLY&& isALNUMC(*p)) {
                            ckWARN2reg(p + 1, "Unrecognized escape \\%.1s passed through", p);
                        }
                        goto normal_default;
@@ -10283,7 +10566,7 @@ tryagain:
                        *tmpbuf = (U8) ender;
                        foldlen = 1;
                    }
-                   else if (! MORE_ASCII_RESTRICTED && ! LOC) {
+                   else if (! ASCII_FOLD_RESTRICTED && ! LOC) {
 
                        /* Locale and /aa require more selectivity about the
                         * fold, so are handled below.  Otherwise, here, just
@@ -10415,22 +10698,12 @@ tryagain:
            if (len == 1 && UNI_IS_INVARIANT(ender))
                *flagp |= SIMPLE;
 
-           if (SIZE_ONLY)
-               RExC_size += STR_SZ(len);
-           else {
-               STR_LEN(ret) = len;
-               RExC_emit += STR_SZ(len);
-            }
+            alloc_maybe_populate_EXACT(pRExC_state, ret, len, 0);
        }
        break;
     }
 
     return(ret);
-
-/* Jumped to when an unrecognized character set is encountered */
-bad_charset:
-    Perl_croak(aTHX_ "panic: Unknown regex character set encoding: %u", get_regex_charset(RExC_flags));
-    return(NULL);
 }
 
 STATIC char *
@@ -10505,7 +10778,7 @@ S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
                    switch (skip) {
                    case 4:
                        if (memEQ(posixcc, "word", 4)) /* this is not POSIX, this is the Perl \w */
-                           namedclass = complement ? ANYOF_NALNUM : ANYOF_ALNUM;
+                           namedclass = ANYOF_ALNUM;
                        break;
                    case 5:
                        /* Names all of length 5.  */
@@ -10515,57 +10788,63 @@ S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
                        switch (posixcc[4]) {
                        case 'a':
                            if (memEQ(posixcc, "alph", 4)) /* alpha */
-                               namedclass = complement ? ANYOF_NALPHA : ANYOF_ALPHA;
+                               namedclass = ANYOF_ALPHA;
                            break;
                        case 'e':
                            if (memEQ(posixcc, "spac", 4)) /* space */
-                               namedclass = complement ? ANYOF_NPSXSPC : ANYOF_PSXSPC;
+                               namedclass = ANYOF_PSXSPC;
                            break;
                        case 'h':
                            if (memEQ(posixcc, "grap", 4)) /* graph */
-                               namedclass = complement ? ANYOF_NGRAPH : ANYOF_GRAPH;
+                               namedclass = ANYOF_GRAPH;
                            break;
                        case 'i':
                            if (memEQ(posixcc, "asci", 4)) /* ascii */
-                               namedclass = complement ? ANYOF_NASCII : ANYOF_ASCII;
+                               namedclass = ANYOF_ASCII;
                            break;
                        case 'k':
                            if (memEQ(posixcc, "blan", 4)) /* blank */
-                               namedclass = complement ? ANYOF_NBLANK : ANYOF_BLANK;
+                               namedclass = ANYOF_BLANK;
                            break;
                        case 'l':
                            if (memEQ(posixcc, "cntr", 4)) /* cntrl */
-                               namedclass = complement ? ANYOF_NCNTRL : ANYOF_CNTRL;
+                               namedclass = ANYOF_CNTRL;
                            break;
                        case 'm':
                            if (memEQ(posixcc, "alnu", 4)) /* alnum */
-                               namedclass = complement ? ANYOF_NALNUMC : ANYOF_ALNUMC;
+                               namedclass = ANYOF_ALNUMC;
                            break;
                        case 'r':
                            if (memEQ(posixcc, "lowe", 4)) /* lower */
-                               namedclass = complement ? ANYOF_NLOWER : ANYOF_LOWER;
+                               namedclass = ANYOF_LOWER;
                            else if (memEQ(posixcc, "uppe", 4)) /* upper */
-                               namedclass = complement ? ANYOF_NUPPER : ANYOF_UPPER;
+                               namedclass = ANYOF_UPPER;
                            break;
                        case 't':
                            if (memEQ(posixcc, "digi", 4)) /* digit */
-                               namedclass = complement ? ANYOF_NDIGIT : ANYOF_DIGIT;
+                               namedclass = ANYOF_DIGIT;
                            else if (memEQ(posixcc, "prin", 4)) /* print */
-                               namedclass = complement ? ANYOF_NPRINT : ANYOF_PRINT;
+                               namedclass = ANYOF_PRINT;
                            else if (memEQ(posixcc, "punc", 4)) /* punct */
-                               namedclass = complement ? ANYOF_NPUNCT : ANYOF_PUNCT;
+                               namedclass = ANYOF_PUNCT;
                            break;
                        }
                        break;
                    case 6:
                        if (memEQ(posixcc, "xdigit", 6))
-                           namedclass = complement ? ANYOF_NXDIGIT : ANYOF_XDIGIT;
+                           namedclass = ANYOF_XDIGIT;
                        break;
                    }
 
                    if (namedclass == OOB_NAMEDCLASS)
                        Simple_vFAIL3("POSIX class [:%.*s:] unknown",
                                      t - s - 1, s + 1);
+
+                    /* The #defines are structured so each complement is +1 to
+                     * the normal one */
+                    if (complement) {
+                        namedclass++;
+                    }
                    assert (posixcc[skip] == ':');
                    assert (posixcc[skip+1] == ']');
                } else if (!SIZE_ONLY) {
@@ -10696,7 +10975,7 @@ S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
  *                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
+ *                to it, appropriately
  * 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,      \
@@ -10722,16 +11001,18 @@ S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
     }
 
 /* Like DO_POSIX_LATIN1_ONLY_KNOWN, but for the complement.  A combination of
- * this and DO_N_POSIX */
+ * this and DO_N_POSIX.  Sets <matches_above_unicode> only if it can; unchanged
+ * otherwise */
 #define DO_N_POSIX_LATIN1_ONLY_KNOWN(node, class, destlist, sourcelist,    \
-                              l1_sourcelist, Xpropertyname, run_time_list) \
+       l1_sourcelist, Xpropertyname, run_time_list, matches_above_unicode) \
     if (AT_LEAST_ASCII_RESTRICTED) {                                       \
         _invlist_union_complement_2nd(destlist, sourcelist, &destlist);    \
     }                                                                      \
     else {                                                                 \
         Perl_sv_catpvf(aTHX_ run_time_list, "!utf8::%s\n", Xpropertyname); \
+        matches_above_unicode = TRUE;                                      \
        if (LOC) {                                                         \
-           ANYOF_CLASS_SET(node, namedclass);                             \
+            ANYOF_CLASS_SET(node, namedclass);                            \
        }                                                                  \
        else {                                                             \
             SV* scratch_list = NULL;                                       \
@@ -10749,171 +11030,6 @@ S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
        }                                                                  \
     }
 
-STATIC U8
-S_set_regclass_bit_fold(pTHX_ RExC_state_t *pRExC_state, regnode* node, const U8 value, SV** invlist_ptr, AV** alternate_ptr)
-{
-
-    /* Handle the setting of folds in the bitmap for non-locale ANYOF nodes.
-     * Locale folding is done at run-time, so this function should not be
-     * called for nodes that are for locales.
-     *
-     * This function sets the bit corresponding to the fold of the input
-     * 'value', if not already set.  The fold of 'f' is 'F', and the fold of
-     * 'F' is 'f'.
-     *
-     * It also knows about the characters that are in the bitmap that have
-     * folds that are matchable only outside it, and sets the appropriate lists
-     * and flags.
-     *
-     * It returns the number of bits that actually changed from 0 to 1 */
-
-    U8 stored = 0;
-    U8 fold;
-
-    PERL_ARGS_ASSERT_SET_REGCLASS_BIT_FOLD;
-
-    fold = (AT_LEAST_UNI_SEMANTICS) ? PL_fold_latin1[value]
-                                    : PL_fold[value];
-
-    /* It assumes the bit for 'value' has already been set */
-    if (fold != value && ! ANYOF_BITMAP_TEST(node, fold)) {
-        ANYOF_BITMAP_SET(node, fold);
-        stored++;
-    }
-    if (_HAS_NONLATIN1_FOLD_CLOSURE_ONLY_FOR_USE_BY_REGCOMP_DOT_C_AND_REGEXEC_DOT_C(value) && (! isASCII(value) || ! MORE_ASCII_RESTRICTED)) {
-       /* Certain Latin1 characters have matches outside the bitmap.  To get
-        * here, 'value' is one of those characters.   None of these matches is
-        * valid for ASCII characters under /aa, which have been excluded by
-        * the 'if' above.  The matches fall into three categories:
-        * 1) They are singly folded-to or -from an above 255 character, as
-        *    LATIN SMALL LETTER Y WITH DIAERESIS and LATIN CAPITAL LETTER Y
-        *    WITH DIAERESIS;
-        * 2) They are part of a multi-char fold with another character in the
-        *    bitmap, only LATIN SMALL LETTER SHARP S => "ss" fits that bill;
-        * 3) They are part of a multi-char fold with a character not in the
-        *    bitmap, such as various ligatures.
-        * We aren't dealing fully with multi-char folds, except we do deal
-        * with the pattern containing a character that has a multi-char fold
-        * (not so much the inverse).
-        * For types 1) and 3), the matches only happen when the target string
-        * is utf8; that's not true for 2), and we set a flag for it.
-        *
-        * The code below adds to the passed in inversion list the single fold
-        * closures for 'value'.  The values are hard-coded here so that an
-        * innocent-looking character class, like /[ks]/i won't have to go out
-        * to disk to find the possible matches.  XXX It would be better to
-        * generate these via regen, in case a new version of the Unicode
-        * standard adds new mappings, though that is not really likely. */
-       switch (value) {
-           case 'k':
-           case 'K':
-               /* KELVIN SIGN */
-               *invlist_ptr = add_cp_to_invlist(*invlist_ptr, 0x212A);
-               break;
-           case 's':
-           case 'S':
-               /* LATIN SMALL LETTER LONG S */
-               *invlist_ptr = add_cp_to_invlist(*invlist_ptr, 0x017F);
-               break;
-           case MICRO_SIGN:
-               *invlist_ptr = add_cp_to_invlist(*invlist_ptr,
-                                                GREEK_SMALL_LETTER_MU);
-               *invlist_ptr = add_cp_to_invlist(*invlist_ptr,
-                                                GREEK_CAPITAL_LETTER_MU);
-               break;
-           case LATIN_CAPITAL_LETTER_A_WITH_RING_ABOVE:
-           case LATIN_SMALL_LETTER_A_WITH_RING_ABOVE:
-               /* ANGSTROM SIGN */
-               *invlist_ptr = add_cp_to_invlist(*invlist_ptr, 0x212B);
-               if (DEPENDS_SEMANTICS) {    /* See DEPENDS comment below */
-                   *invlist_ptr = add_cp_to_invlist(*invlist_ptr,
-                                                    PL_fold_latin1[value]);
-               }
-               break;
-           case LATIN_SMALL_LETTER_Y_WITH_DIAERESIS:
-               *invlist_ptr = add_cp_to_invlist(*invlist_ptr,
-                                       LATIN_CAPITAL_LETTER_Y_WITH_DIAERESIS);
-               break;
-           case LATIN_SMALL_LETTER_SHARP_S:
-               *invlist_ptr = add_cp_to_invlist(*invlist_ptr,
-                                       LATIN_CAPITAL_LETTER_SHARP_S);
-
-               /* Under /a, /d, and /u, this can match the two chars "ss" */
-               if (! MORE_ASCII_RESTRICTED) {
-                   add_alternate(alternate_ptr, (U8 *) "ss", 2);
-
-                   /* And under /u or /a, it can match even if the target is
-                    * not utf8 */
-                   if (AT_LEAST_UNI_SEMANTICS) {
-                       ANYOF_FLAGS(node) |= ANYOF_NONBITMAP_NON_UTF8;
-                   }
-               }
-               break;
-           case 'F': case 'f':
-           case 'I': case 'i':
-           case 'L': case 'l':
-           case 'T': case 't':
-           case 'A': case 'a':
-           case 'H': case 'h':
-           case 'J': case 'j':
-           case 'N': case 'n':
-           case 'W': case 'w':
-           case 'Y': case 'y':
-                /* These all are targets of multi-character folds from code
-                 * points that require UTF8 to express, so they can't match
-                 * unless the target string is in UTF-8, so no action here is
-                 * necessary, as regexec.c properly handles the general case
-                 * for UTF-8 matching */
-               break;
-           default:
-               /* Use deprecated warning to increase the chances of this
-                * being output */
-               ckWARN2regdep(RExC_parse, "Perl folding rules are not up-to-date for 0x%x; please use the perlbug utility to report;", value);
-               break;
-       }
-    }
-    else if (DEPENDS_SEMANTICS
-           && ! isASCII(value)
-           && PL_fold_latin1[value] != value)
-    {
-          /* Under DEPENDS rules, non-ASCII Latin1 characters match their
-           * folds only when the target string is in UTF-8.  We add the fold
-           * here to the list of things to match outside the bitmap, which
-           * won't be looked at unless it is UTF8 (or else if something else
-           * says to look even if not utf8, but those things better not happen
-           * under DEPENDS semantics. */
-       *invlist_ptr = add_cp_to_invlist(*invlist_ptr, PL_fold_latin1[value]);
-    }
-
-    return stored;
-}
-
-
-PERL_STATIC_INLINE U8
-S_set_regclass_bit(pTHX_ RExC_state_t *pRExC_state, regnode* node, const U8 value, SV** invlist_ptr, AV** alternate_ptr)
-{
-    /* This inline function sets a bit in the bitmap if not already set, and if
-     * appropriate, its fold, returning the number of bits that actually
-     * changed from 0 to 1 */
-
-    U8 stored;
-
-    PERL_ARGS_ASSERT_SET_REGCLASS_BIT;
-
-    if (ANYOF_BITMAP_TEST(node, value)) {   /* Already set */
-       return 0;
-    }
-
-    ANYOF_BITMAP_SET(node, value);
-    stored = 1;
-
-    if (FOLD && ! LOC) {       /* Locale folds aren't known until runtime */
-       stored += set_regclass_bit_fold(pRExC_state, node, value, invlist_ptr, alternate_ptr);
-    }
-
-    return stored;
-}
-
 STATIC void
 S_add_alternate(pTHX_ AV** alternate_ptr, U8* string, STRLEN len)
 {
@@ -10932,6 +11048,11 @@ S_add_alternate(pTHX_ AV** alternate_ptr, U8* string, STRLEN len)
     return;
 }
 
+/* The names of properties whose definitions are not known at compile time are
+ * stored in this SV, after a constant heading.  So if the length has been
+ * changed since initialization, then there is a run-time definition. */
+#define HAS_NONLOCALE_RUNTIME_PROPERTY_DEFINITION (SvCUR(listsv) != initial_listsv_len)
+
 /*
    parse a class specification and produce either an ANYOF node that
    matches the pattern or perhaps will be optimized into an EXACTish node
@@ -10944,12 +11065,12 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, U32 depth)
 {
     dVAR;
     register UV nextvalue;
-    register IV prevvalue = OOB_UNICODE;
+    register UV prevvalue = OOB_UNICODE;
     register IV range = 0;
     UV value = 0; /* XXX:dmq: needs to be referenceable (unfortunately) */
     register regnode *ret;
     STRLEN numlen;
-    IV namedclass;
+    IV namedclass = OOB_NAMEDCLASS;
     char *rangebegin = NULL;
     bool need_class = 0;
     bool allow_full_fold = TRUE;   /* Assume wants multi-char folding */
@@ -10957,6 +11078,8 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, U32 depth)
     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{} */
+    SV* posixes = NULL;     /* Code points that match classes like, [:word:],
+                               extended beyond the Latin1 range */
     UV element_count = 0;   /* Number of distinct elements in the class.
                               Optimizations may be possible if this is tiny */
     UV n;
@@ -10971,37 +11094,35 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, U32 depth)
 
     /* 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;
-
-    /* The items that are to match that aren't stored in the bitmap, but are a
-     * result of things that are stored there.  This is the fold closure of
-     * such a character, either because it has DEPENDS semantics and shouldn't
-     * be matched unless the target string is utf8, or is a code point that is
-     * too large for the bit map, as for example, the fold of the MICRO SIGN is
-     * above 255.  This all is solely for performance reasons.  By having this
-     * code know the outside-the-bitmap folds that the bitmapped characters are
-     * involved with, we don't have to go out to disk to find the list of
-     * matches, unless the character class includes code points that aren't
-     * storable in the bit map.  That means that a character class with an 's'
-     * in it, for example, doesn't need to go out to disk to find everything
-     * that matches.  A 2nd list is used so that the 'nonbitmap' list is kept
-     * empty unless there is something whose fold we don't know about, and will
-     * have to go out to the disk to find. */
-    SV* l1_fold_invlist = NULL;
+    bool has_user_defined_property = FALSE;
+
+    /* inversion list of code points this node matches only when the target
+     * string is in UTF-8.  (Because is under /d) */
+    SV* depends_list = NULL;
+
+    /* inversion list of code points this node matches.  For much of the
+     * function, it includes only those that match regardless of the utf8ness
+     * of the target string */
+    SV* cp_list = NULL;
 
     /* List of multi-character folds that are matched by this node */
     AV* unicode_alternate  = NULL;
 #ifdef EBCDIC
+    /* In a range, counts how many 0-2 of the ends of it came from literals,
+     * not escapes.  Thus we can tell if 'A' was input vs \x{C1} */
     UV literal_endpoint = 0;
 #endif
     UV stored = 0;  /* how many chars stored in the bitmap */
+    bool invert = FALSE;    /* Is this class to be complemented */
+
+    /* Is there any thing like \W or [:^digit:] that matches above the legal
+     * Unicode range? */
+    bool runtime_posix_matches_above_Unicode = FALSE;
 
     regnode * const orig_emit = RExC_emit; /* Save the original RExC_emit in
         case we need to change the emitted regop to an EXACT. */
     const char * orig_parse = RExC_parse;
+    const I32 orig_size = RExC_size;
     GET_RE_DEBUG_FLAGS_DECL;
 
     PERL_ARGS_ASSERT_REGCLASS;
@@ -11022,8 +11143,7 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, U32 depth)
     if (UCHARAT(RExC_parse) == '^') {  /* Complement of range. */
        RExC_naughty++;
        RExC_parse++;
-       if (!SIZE_ONLY)
-           ANYOF_FLAGS(ret) |= ANYOF_INVERT;
+        invert = TRUE;
 
         /* We have decided to not allow multi-char folds in inverted character
         * classes, due to the confusion that can happen, especially with
@@ -11045,7 +11165,6 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, U32 depth)
        if (LOC) {
            ANYOF_FLAGS(ret) |= ANYOF_LOCALE;
        }
-       ANYOF_BITMAP_ZERO(ret);
        listsv = newSVpvs("# comment\n");
        initial_listsv_len = SvCUR(listsv);
     }
@@ -11148,6 +11267,7 @@ parseit:
                     SV** invlistsvp;
                     SV* invlist;
                     char* name;
+
                    if (UCHARAT(RExC_parse) == '^') {
                         RExC_parse++;
                         n--;
@@ -11202,11 +11322,15 @@ parseit:
                         Perl_sv_catpvf(aTHX_ listsv, "%cutf8::%s\n",
                                         (value == 'p' ? '+' : '!'),
                                         name);
-                        has_user_defined_property = 1;
+                        has_user_defined_property = TRUE;
 
                         /* 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 */
+                         * hence something that isn't utf8.  Note that this
+                         * would cause things in <depends_list> to match
+                         * inappropriately, except that any \p{}, including
+                         * this one forces Unicode semantics, which means there
+                         * is <no depends_list> */
                         ANYOF_FLAGS(ret) |= ANYOF_NONBITMAP_NON_UTF8;
                     }
                     else {
@@ -11214,17 +11338,14 @@ parseit:
                         /* 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);
-                        }
+                        has_user_defined_property =
+                                                _is_swash_user_defined(swash);
 
                         /* Invert if asking for the complement */
                         if (value == 'P') {
-                           _invlist_union_complement_2nd(properties, invlist, &properties);
+                           _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
@@ -11271,22 +11392,18 @@ parseit:
                }
                break;
            case 'x':
-               if (*RExC_parse == '{') {
-                    I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
-                        | PERL_SCAN_DISALLOW_PREFIX;
-                   char * const e = strchr(RExC_parse++, '}');
-                    if (!e)
-                        vFAIL("Missing right brace on \\x{}");
-
-                   numlen = e - RExC_parse;
-                   value = grok_hex(RExC_parse, &numlen, &flags, NULL);
-                   RExC_parse = e + 1;
-               }
-               else {
-                    I32 flags = PERL_SCAN_DISALLOW_PREFIX;
-                   numlen = 2;
-                   value = grok_hex(RExC_parse, &numlen, &flags, NULL);
+               RExC_parse--;   /* function expects to be pointed at the 'x' */
+               {
+                   const char* error_msg;
+                   bool valid = grok_bslash_x(RExC_parse,
+                                              &value,
+                                              &numlen,
+                                              &error_msg,
+                                              1);
                    RExC_parse += numlen;
+                   if (! valid) {
+                       vFAIL(error_msg);
+                   }
                }
                if (PL_encoding && value < 0x100)
                    goto recode_encoding;
@@ -11330,15 +11447,20 @@ parseit:
            literal_endpoint++;
 #endif
 
-       if (namedclass > OOB_NAMEDCLASS) { /* this is a named class \blah */
-
-           /* What matches in a locale is not known until runtime, so need to
-            * (one time per class) allocate extra space to pass to regexec.
-            * The space will contain a bit for each named class that is to be
-            * matched against.  This isn't needed for \p{} and pseudo-classes,
-            * as they are not affected by locale, and hence are dealt with
-            * separately */
-           if (LOC && namedclass < ANYOF_MAX && ! need_class) {
+            /* What matches in a locale is not known until runtime.  This
+             * includes what the Posix classes (like \w, [:space:]) match.
+             * Room must be reserved (one time per class) to store such
+             * classes, either if Perl is compiled so that locale nodes always
+             * should have this space, or if there is such class info to be
+             * stored.  The space will contain a bit for each named class that
+             * is to be matched against.  This isn't needed for \p{} and
+             * pseudo-classes, as they are not affected by locale, and hence
+             * are dealt with separately */
+           if (LOC
+                && ! need_class
+                && (ANYOF_LOCALE == ANYOF_CLASS
+                    || (namedclass > OOB_NAMEDCLASS && namedclass < ANYOF_MAX)))
+            {
                need_class = 1;
                if (SIZE_ONLY) {
                    RExC_size += ANYOF_CLASS_SKIP - ANYOF_SKIP;
@@ -11350,6 +11472,8 @@ parseit:
                ANYOF_FLAGS(ret) |= ANYOF_CLASS;
            }
 
+       if (namedclass > OOB_NAMEDCLASS) { /* this is a named class \blah */
+
            /* a bad range like a-\d, a-[:digit:].  The '-' is taken as a
             * literal, as is the character that began the false range, i.e.
             * the 'a' in the examples */
@@ -11361,51 +11485,41 @@ parseit:
                    ckWARN4reg(RExC_parse,
                               "False [] range \"%*.*s\"",
                               w, w, rangebegin);
-
-                   stored +=
-                         set_regclass_bit(pRExC_state, ret, '-', &l1_fold_invlist, &unicode_alternate);
-                   if (prevvalue < 256) {
-                       stored +=
-                         set_regclass_bit(pRExC_state, ret, (U8) prevvalue, &l1_fold_invlist, &unicode_alternate);
-                   }
-                   else {
-                       nonbitmap = add_cp_to_invlist(nonbitmap, prevvalue);
-                   }
+                    cp_list = add_cp_to_invlist(cp_list, '-');
+                    cp_list = add_cp_to_invlist(cp_list, prevvalue);
                }
 
                range = 0; /* this was not a true range */
+                element_count += 2; /* So counts for three values */
            }
 
-           if (!SIZE_ONLY) {
-
-               /* 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 */
+           if (! SIZE_ONLY) {
                switch ((I32)namedclass) {
 
                case ANYOF_ALNUMC: /* C's alnum, in contrast to \w */
-                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
                         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);
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
+                        PL_PosixAlnum, PL_L1PosixAlnum, "XPosixAlnum", listsv,
+                        runtime_posix_matches_above_Unicode);
                    break;
                case ANYOF_ALPHA:
-                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
                         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);
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
+                        PL_PosixAlpha, PL_L1PosixAlpha, "XPosixAlpha", listsv,
+                        runtime_posix_matches_above_Unicode);
                    break;
                case ANYOF_ASCII:
                    if (LOC) {
                        ANYOF_CLASS_SET(ret, namedclass);
                    }
                     else {
-                        _invlist_union(properties, PL_ASCII, &properties);
+                        _invlist_union(posixes, PL_ASCII, &posixes);
                     }
                    break;
                case ANYOF_NASCII:
@@ -11413,59 +11527,61 @@ parseit:
                        ANYOF_CLASS_SET(ret, namedclass);
                    }
                     else {
-                        _invlist_union_complement_2nd(properties,
-                                                    PL_ASCII, &properties);
+                        _invlist_union_complement_2nd(posixes,
+                                                    PL_ASCII, &posixes);
                         if (DEPENDS_SEMANTICS) {
                             ANYOF_FLAGS(ret) |= ANYOF_NON_UTF8_LATIN1_ALL;
                         }
                     }
                    break;
                case ANYOF_BLANK:
-                    DO_POSIX(ret, namedclass, properties,
+                    DO_POSIX(ret, namedclass, posixes,
                                             PL_PosixBlank, PL_XPosixBlank);
                    break;
                case ANYOF_NBLANK:
-                    DO_N_POSIX(ret, namedclass, properties,
+                    DO_N_POSIX(ret, namedclass, posixes,
                                             PL_PosixBlank, PL_XPosixBlank);
                    break;
                case ANYOF_CNTRL:
-                    DO_POSIX(ret, namedclass, properties,
+                    DO_POSIX(ret, namedclass, posixes,
                                             PL_PosixCntrl, PL_XPosixCntrl);
                    break;
                case ANYOF_NCNTRL:
-                    DO_N_POSIX(ret, namedclass, properties,
+                    DO_N_POSIX(ret, namedclass, posixes,
                                             PL_PosixCntrl, PL_XPosixCntrl);
                    break;
                case ANYOF_DIGIT:
                    /* There are no digits in the Latin1 range outside of
                     * ASCII, so call the macro that doesn't have to resolve
                     * them */
-                   DO_POSIX_LATIN1_ONLY_KNOWN_L1_RESOLVED(ret, namedclass, properties,
+                   DO_POSIX_LATIN1_ONLY_KNOWN_L1_RESOLVED(ret, namedclass, posixes,
                         PL_PosixDigit, "XPosixDigit", listsv);
                    break;
                case ANYOF_NDIGIT:
-                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
-                        PL_PosixDigit, PL_PosixDigit, "XPosixDigit", listsv);
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
+                        PL_PosixDigit, PL_PosixDigit, "XPosixDigit", listsv,
+                        runtime_posix_matches_above_Unicode);
                    break;
                case ANYOF_GRAPH:
-                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
                         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);
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
+                        PL_PosixGraph, PL_L1PosixGraph, "XPosixGraph", listsv,
+                        runtime_posix_matches_above_Unicode);
                    break;
                case ANYOF_HORIZWS:
-                   /* For these, we use the nonbitmap, as /d doesn't make a
+                   /* For these, we use the cp_list, 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.  It turns out that \h
+                    * cp_list is subject to folding.  It turns out that \h
                     * is just a synonym for XPosixBlank */
-                   _invlist_union(nonbitmap, PL_XPosixBlank, &nonbitmap);
+                   _invlist_union(cp_list, PL_XPosixBlank, &cp_list);
                    break;
                case ANYOF_NHORIZWS:
-                    _invlist_union_complement_2nd(nonbitmap,
-                                                 PL_XPosixBlank, &nonbitmap);
+                    _invlist_union_complement_2nd(cp_list,
+                                                 PL_XPosixBlank, &cp_list);
                    break;
                case ANYOF_LOWER:
                case ANYOF_NLOWER:
@@ -11488,45 +11604,48 @@ parseit:
                        Xname = "XPosixLower";
                    }
                    if (namedclass == ANYOF_LOWER) {
-                       DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                       DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
                                     ascii_source, l1_source, Xname, listsv);
                    }
                    else {
                        DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass,
-                            properties, ascii_source, l1_source, Xname, listsv);
+                            posixes, ascii_source, l1_source, Xname, listsv,
+                            runtime_posix_matches_above_Unicode);
                    }
                    break;
                }
                case ANYOF_PRINT:
-                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
                         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);
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
+                        PL_PosixPrint, PL_L1PosixPrint, "XPosixPrint", listsv,
+                        runtime_posix_matches_above_Unicode);
                    break;
                case ANYOF_PUNCT:
-                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
                         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);
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
+                        PL_PosixPunct, PL_L1PosixPunct, "XPosixPunct", listsv,
+                        runtime_posix_matches_above_Unicode);
                    break;
                case ANYOF_PSXSPC:
-                    DO_POSIX(ret, namedclass, properties,
+                    DO_POSIX(ret, namedclass, posixes,
                                             PL_PosixSpace, PL_XPosixSpace);
                    break;
                case ANYOF_NPSXSPC:
-                    DO_N_POSIX(ret, namedclass, properties,
+                    DO_N_POSIX(ret, namedclass, posixes,
                                             PL_PosixSpace, PL_XPosixSpace);
                    break;
                case ANYOF_SPACE:
-                    DO_POSIX(ret, namedclass, properties,
+                    DO_POSIX(ret, namedclass, posixes,
                                             PL_PerlSpace, PL_XPerlSpace);
                    break;
                case ANYOF_NSPACE:
-                    DO_N_POSIX(ret, namedclass, properties,
+                    DO_N_POSIX(ret, namedclass, posixes,
                                             PL_PerlSpace, PL_XPerlSpace);
                    break;
                case ANYOF_UPPER:   /* Same as LOWER, above */
@@ -11547,40 +11666,42 @@ parseit:
                        Xname = "XPosixUpper";
                    }
                    if (namedclass == ANYOF_UPPER) {
-                       DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                       DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
                                     ascii_source, l1_source, Xname, listsv);
                    }
                    else {
                        DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass,
-                        properties, ascii_source, l1_source, Xname, listsv);
+                        posixes, ascii_source, l1_source, Xname, listsv,
+                        runtime_posix_matches_above_Unicode);
                    }
                    break;
                }
                case ANYOF_ALNUM:   /* Really is 'Word' */
-                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
                             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);
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, posixes,
+                            PL_PosixWord, PL_L1PosixWord, "XPosixWord", listsv,
+                            runtime_posix_matches_above_Unicode);
                    break;
                case ANYOF_VERTWS:
-                   /* For these, we use the nonbitmap, as /d doesn't make a
+                   /* For these, we use the cp_list, 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);
+                    * cp_list is subject to folding */
+                   _invlist_union(cp_list, PL_VertSpace, &cp_list);
                    break;
                case ANYOF_NVERTWS:
-                    _invlist_union_complement_2nd(nonbitmap,
-                                                    PL_VertSpace, &nonbitmap);
+                    _invlist_union_complement_2nd(cp_list,
+                                                    PL_VertSpace, &cp_list);
                    break;
                case ANYOF_XDIGIT:
-                    DO_POSIX(ret, namedclass, properties,
+                    DO_POSIX(ret, namedclass, posixes,
                                             PL_PosixXDigit, PL_XPosixXDigit);
                    break;
                case ANYOF_NXDIGIT:
-                    DO_N_POSIX(ret, namedclass, properties,
+                    DO_N_POSIX(ret, namedclass, posixes,
                                             PL_PosixXDigit, PL_XPosixXDigit);
                    break;
                case ANYOF_MAX:
@@ -11591,19 +11712,19 @@ parseit:
                    break;
                }
 
-               continue;
+               continue;   /* Go get next character */
            }
        } /* end of namedclass \blah */
 
        if (range) {
-           if (prevvalue > (IV)value) /* b-a */ {
+           if (prevvalue > value) /* b-a */ {
                const int w = RExC_parse - rangebegin;
                Simple_vFAIL4("Invalid [] range \"%*.*s\"", w, w, rangebegin);
                range = 0; /* not a valid range */
            }
        }
        else {
-           prevvalue = value; /* save the beginning of the range */
+            prevvalue = value; /* save the beginning of the potential range */
            if (RExC_parse+1 < RExC_end
                && *RExC_parse == '-'
                && RExC_parse[1] != ']')
@@ -11620,135 +11741,416 @@ parseit:
                               "False [] range \"%*.*s\"",
                               w, w, rangebegin);
                    }
-                   if (!SIZE_ONLY)
-                       stored +=
-                            set_regclass_bit(pRExC_state, ret, '-', &l1_fold_invlist, &unicode_alternate);
+                    if (!SIZE_ONLY)
+                        cp_list = add_cp_to_invlist(cp_list, '-');
                } else
                    range = 1;  /* yeah, it's a range! */
                continue;       /* but do it the next time */
            }
        }
 
+        /* Here, <prevvalue> is the beginning of the range, if any; or <value>
+         * if not */
+
        /* non-Latin1 code point implies unicode semantics.  Must be set in
         * pass1 so is there for the whole of pass 2 */
        if (value > 255) {
            RExC_uni_semantics = 1;
        }
 
-       /* now is the next time */
+        /* Ready to process either the single value, or the completed range */
        if (!SIZE_ONLY) {
-           if (prevvalue < 256) {
-               const IV ceilvalue = value < 256 ? value : 255;
-               IV i;
-#ifdef EBCDIC
-               /* In EBCDIC [\x89-\x91] should include
-                * the \x8e but [i-j] should not. */
-               if (literal_endpoint == 2 &&
-                   ((isLOWER(prevvalue) && isLOWER(ceilvalue)) ||
-                    (isUPPER(prevvalue) && isUPPER(ceilvalue))))
-               {
-                   if (isLOWER(prevvalue)) {
-                       for (i = prevvalue; i <= ceilvalue; i++)
-                           if (isLOWER(i) && !ANYOF_BITMAP_TEST(ret,i)) {
-                               stored +=
-                                  set_regclass_bit(pRExC_state, ret, (U8) i, &l1_fold_invlist, &unicode_alternate);
-                           }
-                   } else {
-                       for (i = prevvalue; i <= ceilvalue; i++)
-                           if (isUPPER(i) && !ANYOF_BITMAP_TEST(ret,i)) {
-                               stored +=
-                                  set_regclass_bit(pRExC_state, ret, (U8) i, &l1_fold_invlist, &unicode_alternate);
-                           }
-                   }
-               }
-               else
-#endif
-                     for (i = prevvalue; i <= ceilvalue; i++) {
-                       stored += set_regclass_bit(pRExC_state, ret, (U8) i, &l1_fold_invlist, &unicode_alternate);
-                     }
-         }
-         if (value > 255) {
-           const UV prevnatvalue  = NATIVE_TO_UNI(prevvalue);
-           const UV natvalue      = NATIVE_TO_UNI(value);
-           nonbitmap = _add_range_to_invlist(nonbitmap, prevnatvalue, natvalue);
-       }
-#ifdef EBCDIC
-           literal_endpoint = 0;
+#ifndef EBCDIC
+            cp_list = _add_range_to_invlist(cp_list, prevvalue, value);
+#else
+            UV* this_range = _new_invlist(1);
+            _append_range_to_invlist(this_range, prevvalue, value);
+
+            /* In EBCDIC, the ranges 'A-Z' and 'a-z' are each not contiguous.
+             * If this range was specified using something like 'i-j', we want
+             * to include only the 'i' and the 'j', and not anything in
+             * between, so exclude non-ASCII, non-alphabetics from it.
+             * However, if the range was specified with something like
+             * [\x89-\x91] or [\x89-j], all code points within it should be
+             * included.  literal_endpoint==2 means both ends of the range used
+             * a literal character, not \x{foo} */
+           if (literal_endpoint == 2
+                && (prevvalue >= 'a' && value <= 'z')
+                    || (prevvalue >= 'A' && value <= 'Z'))
+            {
+                _invlist_intersection(this_range, PL_ASCII, &this_range, );
+                _invlist_intersection(this_range, PL_Alpha, &this_range, );
+            }
+            _invlist_union(cp_list, this_range, &cp_list);
+            literal_endpoint = 0;
 #endif
         }
 
        range = 0; /* this range (if it was one) is done now */
-    }
+    } /* End of loop through all the text within the brackets */
+
+    /* If the character class contains only a single element, it may be
+     * optimizable into another node type which is smaller and runs faster.
+     * Check if this is the case for this class */
+    if (element_count == 1) {
+        U8 op = END;
+
+        if (namedclass > OOB_NAMEDCLASS) { /* this is a named class, like \w or
+                                              [:digit:] or \p{foo} */
+
+            /* Certain named classes have equivalents that can appear outside a
+             * character class, e.g. \w, \H.  We use these instead of a
+             * character class. */
+            switch ((I32)namedclass) {
+                U8 offset;
+
+                /* The first group is for node types that depend on the charset
+                 * modifier to the regex.  We first calculate the base node
+                 * type, and if it should be inverted */
+
+                case ANYOF_NALNUM:
+                    invert = ! invert;
+                    /* FALLTHROUGH */
+                case ANYOF_ALNUM:
+                    op = ALNUM;
+                    goto join_charset_classes;
+
+                case ANYOF_NSPACE:
+                    invert = ! invert;
+                    /* FALLTHROUGH */
+                case ANYOF_SPACE:
+                    op = SPACE;
+                    goto join_charset_classes;
+
+                case ANYOF_NDIGIT:
+                    invert = ! invert;
+                    /* FALLTHROUGH */
+                case ANYOF_DIGIT:
+                    op = DIGIT;
+
+                  join_charset_classes:
+
+                    /* Now that we have the base node type, we take advantage
+                     * of the enum ordering of the charset modifiers to get the
+                     * exact node type,  For example the base SPACE also has
+                     * SPACEL, SPACEU, and SPACEA */
+
+                    offset = get_regex_charset(RExC_flags);
+
+                    /* /aa is the same as /a for these */
+                    if (offset == REGEX_ASCII_MORE_RESTRICTED_CHARSET) {
+                        offset = REGEX_ASCII_RESTRICTED_CHARSET;
+                    }
+                    else if (op == DIGIT && offset == REGEX_UNICODE_CHARSET) {
+                        offset = REGEX_DEPENDS_CHARSET; /* There is no DIGITU */
+                    }
+
+                    op += offset;
+
+                    /* The number of varieties of each of these is the same,
+                     * hence, so is the delta between the normal and
+                     * complemented nodes */
+                    if (invert) {
+                        op += NALNUM - ALNUM;
+                    }
+                    break;
+
+                /* The second group doesn't depend of the charset modifiers.
+                 * We just have normal and complemented */
+                case ANYOF_NHORIZWS:
+                    invert = ! invert;
+                    /* FALLTHROUGH */
+                case ANYOF_HORIZWS:
+                    op = (invert) ? NHORIZWS : HORIZWS;
+                    break;
+
+                case ANYOF_NVERTWS:
+                    invert = ! invert;
+                    /* FALLTHROUGH */
+                case ANYOF_VERTWS:
+                    op = (invert) ? NVERTWS : VERTWS;
+                    break;
 
 
+            }
+        }
+        else if (value == prevvalue) {
+
+            /* Here, the class consists of just a single code point */
+
+            if (invert) {
+                if (! LOC && value == '\n') {
+                    op = REG_ANY; /* Optimize [^\n] */
+                }
+            }
+            else if (value < 256 || UTF) {
+
+                /* Optimize a single value into an EXACTish node, but not if it
+                 * would require converting the pattern to UTF-8. */
+                op = compute_EXACTish(pRExC_state);
+            }
+        } /* Otherwise is a range */
+        else if (! LOC) {   /* locale could vary these */
+            if (prevvalue == '0') {
+                if (value == '9') {
+                    op = (invert) ? NDIGITA : DIGITA;
+                }
+            }
+        }
+
+        /* Here, we have changed <op> away from its initial value iff we found
+         * an optimization */
+        if (op != END) {
+
+            /* Throw away this ANYOF regnode, and emit the calculated one,
+             * which should correspond to the beginning, not current, state of
+             * the parse */
+            const char * cur_parse = RExC_parse;
+            RExC_parse = (char *)orig_parse;
+            if ( SIZE_ONLY) {
+                if (! LOC) {
+
+                    /* To get locale nodes to not use the full ANYOF size would
+                     * require moving the code above that writes the portions
+                     * of it that aren't in other nodes to after this point.
+                     * e.g.  ANYOF_CLASS_SET */
+                    RExC_size = orig_size;
+                }
+            }
+            else {
+                RExC_emit = (regnode *)orig_emit;
+            }
+
+            ret = reg_node(pRExC_state, op);
+
+            if (PL_regkind[op] == EXACT) {
+                alloc_maybe_populate_EXACT(pRExC_state, ret, 0, value);
+            }
+
+            RExC_parse = (char *) cur_parse;
+
+            SvREFCNT_dec(listsv);
+            return ret;
+        }
+    }
 
     if (SIZE_ONLY)
         return ret;
     /****** !SIZE_ONLY AFTER HERE *********/
 
-    /* If folding and there are code points above 255, we calculate all
-     * characters that could fold to or from the ones already on the list */
-    if (FOLD && nonbitmap) {
+    /* If folding, we calculate all characters that could fold to or from the
+     * ones already on the list */
+    if (FOLD && cp_list) {
        UV start, end;  /* End points of code point ranges */
 
        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);
-       }
+        /* In the Latin1 range, the characters that can be folded-to or -from
+         * are precisely the alphabetic characters.  If the highest code point
+         * is within Latin1, we can use the compiled-in list, and not have to
+         * go out to disk. */
+        if (invlist_highest(cp_list) < 256) {
+            _invlist_intersection(PL_L1PosixAlpha, cp_list, &fold_intersection);
+        }
+        else {
 
-       /* This is a hash that for a particular fold gives all characters
-           * that are involved in it */
-       if (! PL_utf8_foldclosures) {
+            /* Here, there are non-Latin1 code points, so we will have to go
+             * fetch the list of all the characters that participate in folds
+             */
+            if (! PL_utf8_foldable) {
+                SV* swash = swash_init("utf8", "_Perl_Any_Folds",
+                                       &PL_sv_undef, 1, 0);
+                PL_utf8_foldable = _swash_to_invlist(swash);
+                SvREFCNT_dec(swash);
+            }
 
-           /* If we were unable to find any folds, then we likely won't be
-            * able to find the closures.  So just create an empty list.
-            * Folding will effectively be restricted to the non-Unicode rules
-            * hard-coded into Perl.  (This case happens legitimately during
-            * compilation of Perl itself before the Unicode tables are
-            * generated) */
-           if (invlist_len(PL_utf8_foldable) == 0) {
-               PL_utf8_foldclosures = newHV();
-           } else {
-               /* If the folds haven't been read in, call a fold function
-                   * to force that */
-               if (! PL_utf8_tofold) {
-                   U8 dummy[UTF8_MAXBYTES+1];
-                   STRLEN 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);
-           }
-       }
+            /* This is a hash that for a particular fold gives all characters
+             * that are involved in it */
+            if (! PL_utf8_foldclosures) {
+
+                /* If we were unable to find any folds, then we likely won't be
+                 * able to find the closures.  So just create an empty list.
+                 * Folding will effectively be restricted to the non-Unicode
+                 * rules hard-coded into Perl.  (This case happens legitimately
+                 * during compilation of Perl itself before the Unicode tables
+                 * are generated) */
+                if (invlist_len(PL_utf8_foldable) == 0) {
+                    PL_utf8_foldclosures = newHV();
+                }
+                else {
+                    /* If the folds haven't been read in, call a fold function
+                     * to force that */
+                    if (! PL_utf8_tofold) {
+                        U8 dummy[UTF8_MAXBYTES+1];
+                        STRLEN 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 */
-       _invlist_intersection(PL_utf8_foldable, nonbitmap, &fold_intersection);
+            /* 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, cp_list,
+                                  &fold_intersection);
+        }
 
        /* Now look at the foldable characters in this class individually */
        invlist_iterinit(fold_intersection);
        while (invlist_iternext(fold_intersection, &start, &end)) {
            UV j;
 
+            /* Locale folding for Latin1 characters is deferred until runtime */
+            if (LOC && start < 256) {
+                start = 256;
+            }
+
            /* Look at every character in the range */
            for (j = start; j <= end; j++) {
 
-               /* Get its fold */
                U8 foldbuf[UTF8_MAXBYTES_CASE+1];
                STRLEN foldlen;
-               const UV f =
-                    _to_uni_fold_flags(j, foldbuf, &foldlen,
-                                       (allow_full_fold) ? FOLD_FLAGS_FULL : 0);
+                UV f;
+
+                if (j < 256) {
+
+                    /* We have the latin1 folding rules hard-coded here so that
+                     * an innocent-looking character class, like /[ks]/i won't
+                     * have to go out to disk to find the possible matches.
+                     * XXX It would be better to generate these via regen, in
+                     * case a new version of the Unicode standard adds new
+                     * mappings, though that is not really likely, and may be
+                     * caught by the default: case of the switch below. */
+
+                    if (PL_fold_latin1[j] != j) {
+
+                        /* ASCII is always matched; non-ASCII is matched only
+                         * under Unicode rules */
+                        if (isASCII(j) || AT_LEAST_UNI_SEMANTICS) {
+                            cp_list =
+                                add_cp_to_invlist(cp_list, PL_fold_latin1[j]);
+                        }
+                        else {
+                            depends_list =
+                             add_cp_to_invlist(depends_list, PL_fold_latin1[j]);
+                        }
+                    }
+
+                    if (HAS_NONLATIN1_FOLD_CLOSURE(j)
+                        && (! isASCII(j) || ! ASCII_FOLD_RESTRICTED))
+                    {
+                        /* Certain Latin1 characters have matches outside
+                         * Latin1, or are multi-character.  To get here, 'j' is
+                         * one of those characters.   None of these matches is
+                         * valid for ASCII characters under /aa, which is why
+                         * the 'if' just above excludes those.  The matches
+                         * fall into three categories:
+                         * 1) They are singly folded-to or -from an above 255
+                         *    character, e.g., LATIN SMALL LETTER Y WITH
+                         *    DIAERESIS and LATIN CAPITAL LETTER Y WITH
+                         *    DIAERESIS;
+                         * 2) They are part of a multi-char fold with another
+                         *    latin1 character; only LATIN SMALL LETTER
+                         *    SHARP S => "ss" fits this;
+                         * 3) They are part of a multi-char fold with a
+                         *    character outside of Latin1, such as various
+                         *    ligatures.
+                        * We aren't dealing fully with multi-char folds, except
+                        * we do deal with the pattern containing a character
+                        * that has a multi-char fold (not so much the inverse).
+                        * For types 1) and 3), the matches only happen when the
+                        * target string is utf8; that's not true for 2), and we
+                        * set a flag for it.
+                        *
+                        * The code below adds the single fold closures for 'j'
+                        * to the inversion list. */
+                        switch (j) {
+                            case 'k':
+                            case 'K':
+                                cp_list =
+                                    add_cp_to_invlist(cp_list, KELVIN_SIGN);
+                                break;
+                            case 's':
+                            case 'S':
+                                cp_list = add_cp_to_invlist(cp_list,
+                                                    LATIN_SMALL_LETTER_LONG_S);
+                                break;
+                            case MICRO_SIGN:
+                                cp_list = add_cp_to_invlist(cp_list,
+                                                    GREEK_CAPITAL_LETTER_MU);
+                                cp_list = add_cp_to_invlist(cp_list,
+                                                    GREEK_SMALL_LETTER_MU);
+                                break;
+                            case LATIN_CAPITAL_LETTER_A_WITH_RING_ABOVE:
+                            case LATIN_SMALL_LETTER_A_WITH_RING_ABOVE:
+                                cp_list =
+                                    add_cp_to_invlist(cp_list, ANGSTROM_SIGN);
+                                break;
+                            case LATIN_SMALL_LETTER_Y_WITH_DIAERESIS:
+                                cp_list = add_cp_to_invlist(cp_list,
+                                        LATIN_CAPITAL_LETTER_Y_WITH_DIAERESIS);
+                                break;
+                            case LATIN_SMALL_LETTER_SHARP_S:
+                                cp_list = add_cp_to_invlist(cp_list,
+                                                LATIN_CAPITAL_LETTER_SHARP_S);
+
+                                /* Under /a, /d, and /u, this can match the two
+                                 * chars "ss" */
+                                if (! ASCII_FOLD_RESTRICTED) {
+                                    add_alternate(&unicode_alternate,
+                                                  (U8 *) "ss", 2);
+
+                                    /* And under /u or /a, it can match even if
+                                     * the target is not utf8 */
+                                    if (AT_LEAST_UNI_SEMANTICS) {
+                                        ANYOF_FLAGS(ret) |=
+                                                    ANYOF_NONBITMAP_NON_UTF8;
+                                    }
+                                }
+                                break;
+                            case 'F': case 'f':
+                            case 'I': case 'i':
+                            case 'L': case 'l':
+                            case 'T': case 't':
+                            case 'A': case 'a':
+                            case 'H': case 'h':
+                            case 'J': case 'j':
+                            case 'N': case 'n':
+                            case 'W': case 'w':
+                            case 'Y': case 'y':
+                                /* These all are targets of multi-character
+                                 * folds from code points that require UTF8 to
+                                 * express, so they can't match unless the
+                                 * target string is in UTF-8, so no action here
+                                 * is necessary, as regexec.c properly handles
+                                 * the general case for UTF-8 matching */
+                                break;
+                            default:
+                                /* Use deprecated warning to increase the
+                                 * chances of this being output */
+                                ckWARN2regdep(RExC_parse, "Perl folding rules are not up-to-date for 0x%"UVXf"; please use the perlbug utility to report;", j);
+                                break;
+                        }
+                    }
+                    continue;
+                }
+
+                /* Here is an above Latin1 character.  We don't have the rules
+                 * hard-coded for it.  First, get its fold */
+               f = _to_uni_fold_flags(j, foldbuf, &foldlen,
+                                    ((allow_full_fold) ? FOLD_FLAGS_FULL : 0)
+                                    | ((LOC)
+                                        ? FOLD_FLAGS_LOCALE
+                                        : (ASCII_FOLD_RESTRICTED)
+                                            ? FOLD_FLAGS_NOMIX_ASCII
+                                            : 0));
 
                if (foldlen > (STRLEN)UNISKIP(f)) {
 
@@ -11764,54 +12166,25 @@ parseit:
 
                        /* 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) {
-
-                               /* Can't mix ascii with non- under /aa */
-                               if (MORE_ASCII_RESTRICTED
-                                   && (isASCII(*loc) != isASCII(j)))
-                               {
-                                   goto end_multi_fold;
-                               }
-                               if (UTF8_IS_INVARIANT(*loc)
-                                   || UTF8_IS_DOWNGRADEABLE_START(*loc))
-                               {
-                                    /* Can't mix above and below 256 under LOC
-                                     */
-                                   if (LOC) {
-                                       goto end_multi_fold;
-                                   }
-                                   ANYOF_FLAGS(ret)
-                                           |= ANYOF_NONBITMAP_NON_UTF8;
-                                   break;
-                               }
-                               loc += UTF8SKIP(loc);
-                           }
-                       }
+                        * match a non-utf8 target string.  */
+                        while (loc < e) {
+                            if (UTF8_IS_INVARIANT(*loc)
+                                || UTF8_IS_DOWNGRADEABLE_START(*loc))
+                            {
+                                ANYOF_FLAGS(ret)
+                                        |= ANYOF_NONBITMAP_NON_UTF8;
+                                break;
+                            }
+                            loc += UTF8SKIP(loc);
+                        }
 
                        add_alternate(&unicode_alternate, foldbuf, foldlen);
-                   end_multi_fold: ;
-                   }
-
-                   /* This is special-cased, as it is the only letter which
-                    * has both a multi-fold and single-fold in Latin1.  All
-                    * the other chars that have single and multi-folds are
-                    * always in utf8, and the utf8 folding algorithm catches
-                    * them */
-                   if (! LOC && j == LATIN_CAPITAL_LETTER_SHARP_S) {
-                       stored += set_regclass_bit(pRExC_state,
-                                       ret,
-                                       LATIN_SMALL_LETTER_SHARP_S,
-                                       &l1_fold_invlist, &unicode_alternate);
                    }
                }
-               else {
-                   /* Single character fold.  Add everything in its fold
-                    * closure to the list that this node should match */
+                else {
+                    /* Single character fold of above Latin1.  Add everything
+                     * in its fold closure to the list that this node should
+                     * match */
                    SV** listp;
 
                    /* The fold closures data structure is a hash with the keys
@@ -11834,90 +12207,177 @@ parseit:
                            /* /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))))
+                           if ((ASCII_FOLD_RESTRICTED
+                                      && (isASCII(c) != isASCII(j)))
+                               || (LOC && ((c < 256) != (j < 256))))
                            {
                                continue;
                            }
 
-                           if (c < 256 && AT_LEAST_UNI_SEMANTICS) {
-                               stored += set_regclass_bit(pRExC_state,
-                                       ret,
-                                       (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 */
-                           else if ((c < start || c > end)
-                                       && (c > 255
-                                           || ! ANYOF_BITMAP_TEST(ret, c)))
-                           {
-                               nonbitmap = add_cp_to_invlist(nonbitmap, c);
+                            /* Folds involving non-ascii Latin1 characters
+                             * under /d are added to a separate list */
+                           if (isASCII(c) || c > 255 || AT_LEAST_UNI_SEMANTICS)
+                            {
+                               cp_list = add_cp_to_invlist(cp_list, c);
+                            }
+                            else {
+                              depends_list = add_cp_to_invlist(depends_list, c);
                            }
                        }
                    }
                }
-           }
+            }
        }
        SvREFCNT_dec(fold_intersection);
     }
 
-    /* Combine the two lists into one. */
-    if (l1_fold_invlist) {
-       if (nonbitmap) {
-           _invlist_union(nonbitmap, l1_fold_invlist, &nonbitmap);
-           SvREFCNT_dec(l1_fold_invlist);
-       }
-       else {
-           nonbitmap = l1_fold_invlist;
-       }
+    /* And combine the result (if any) with any inversion list from posix
+     * classes.  The lists are kept separate up to now because we don't want to
+     * fold the classes (folding of those is automatically handled by the swash
+     * fetching code) */
+    if (posixes) {
+        if (AT_LEAST_UNI_SEMANTICS) {
+            if (cp_list) {
+                _invlist_union(cp_list, posixes, &cp_list);
+                SvREFCNT_dec(posixes);
+            }
+            else {
+                cp_list = posixes;
+            }
+        }
+        else {
+
+            /* Under /d, we put into a separate list the Latin1 things that
+             * match only when the target string is utf8 */
+            SV* nonascii_but_latin1_properties = NULL;
+            _invlist_intersection(posixes, PL_Latin1,
+                                  &nonascii_but_latin1_properties);
+            _invlist_subtract(nonascii_but_latin1_properties, PL_ASCII,
+                              &nonascii_but_latin1_properties);
+            _invlist_subtract(posixes, nonascii_but_latin1_properties,
+                              &posixes);
+            if (cp_list) {
+                _invlist_union(cp_list, posixes, &cp_list);
+                SvREFCNT_dec(posixes);
+            }
+            else {
+                cp_list = posixes;
+            }
+
+            if (depends_list) {
+                _invlist_union(depends_list, nonascii_but_latin1_properties,
+                               &depends_list);
+                SvREFCNT_dec(nonascii_but_latin1_properties);
+            }
+            else {
+                depends_list = nonascii_but_latin1_properties;
+            }
+        }
     }
 
     /* 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 */
+     * The lists are kept separate up to now so that we can distinguish the two
+     * in regards to matching above-Unicode.  A run-time warning is generated
+     * if a Unicode property is matched against a non-Unicode code point. But,
+     * we allow user-defined properties to match anything, without any warning,
+     * and we also suppress the warning if there is a portion of the character
+     * class that isn't a Unicode property, and which matches above Unicode, \W
+     * or [\x{110000}] for example.
+     * (Note that in this case, unlike the Posix one above, there is no
+     * <depends_list>, because having a Unicode property forces Unicode
+     * semantics */
     if (properties) {
-       if (nonbitmap) {
-           _invlist_union(nonbitmap, properties, &nonbitmap);
-           SvREFCNT_dec(properties);
-       }
-       else {
-           nonbitmap = properties;
-       }
+        bool warn_super = ! has_user_defined_property;
+        if (cp_list) {
+
+            /* If it matters to the final outcome, see if a non-property
+             * component of the class matches above Unicode.  If so, the
+             * warning gets suppressed.  This is true even if just a single
+             * such code point is specified, as though not strictly correct if
+             * another such code point is matched against, the fact that they
+             * are using above-Unicode code points indicates they should know
+             * the issues involved */
+            if (warn_super) {
+                bool non_prop_matches_above_Unicode =
+                            runtime_posix_matches_above_Unicode
+                            | (invlist_highest(cp_list) > PERL_UNICODE_MAX);
+                if (invert) {
+                    non_prop_matches_above_Unicode =
+                                            !  non_prop_matches_above_Unicode;
+                }
+                warn_super = ! non_prop_matches_above_Unicode;
+            }
+
+            _invlist_union(properties, cp_list, &cp_list);
+            SvREFCNT_dec(properties);
+        }
+        else {
+            cp_list = properties;
+        }
+
+        if (warn_super) {
+            ANYOF_FLAGS(ret) |= ANYOF_WARN_SUPER;
+        }
     }
 
-    /* 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) {
+    /* Here, we have calculated what code points should be in the character
+     * class.
+     *
+     * 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 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 (invert
+        && ! LOC
+       && ! depends_list
+       && ! unicode_alternate
+       && ! HAS_NONLOCALE_RUNTIME_PROPERTY_DEFINITION)
+    {
+        _invlist_invert(cp_list);
+
+        /* Any swash can't be used as-is, because we've inverted things */
+        if (swash) {
+            SvREFCNT_dec(swash);
+            swash = NULL;
+        }
+
+       /* Clear the invert flag since have just done it here */
+       invert = FALSE;
+    }
 
-       /* 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;
+    /* Here, <cp_list> contains all the code points we can determine at
+     * compile time that match under all conditions.  Go through it, and
+     * for things that belong in the bitmap, put them there, and delete from
+     * <cp_list> */
+    ANYOF_BITMAP_ZERO(ret);
+    if (cp_list) {
 
        /* 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)) {
+       /* Start looking through <cp_list> */
+       invlist_iterinit(cp_list);
+       while (invlist_iternext(cp_list, &start, &end)) {
            UV high;
            int i;
 
            /* Quit if are above what we should change */
-           if (start > max_cp_to_set) {
+           if (start > 255) {
                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;
+           high = (end < 255) ? end : 255;
            for (i = start; i <= (int) high; i++) {
                if (! ANYOF_BITMAP_TEST(ret, i)) {
                    ANYOF_BITMAP_SET(ret, i);
@@ -11929,140 +12389,31 @@ parseit:
        }
 
         /* Done with loop; remove any code points that are in the bitmap from
-         * <nonbitmap> */
+         * <cp_list> */
        if (change_invlist) {
-           _invlist_subtract(nonbitmap,
-                             (DEPENDS_SEMANTICS)
-                               ? PL_ASCII
-                               : PL_Latin1,
-                              &nonbitmap);
+           _invlist_subtract(cp_list, PL_Latin1, &cp_list);
        }
 
        /* If have completely emptied it, remove it completely */
-       if (invlist_len(nonbitmap) == 0) {
-           SvREFCNT_dec(nonbitmap);
-           nonbitmap = NULL;
+       if (invlist_len(cp_list) == 0) {
+           SvREFCNT_dec(cp_list);
+           cp_list = NULL;
        }
     }
 
-    /* Here, we have calculated what code points should be in the character
-     * 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. */
+    if (invert) {
+        ANYOF_FLAGS(ret) |= ANYOF_INVERT;
+    }
 
-    /* Optimize inverted simple patterns (e.g. [^a-z]).  Note that we haven'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 ((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, 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 (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;
+    /* Combine the two lists into one. */
+    if (depends_list) {
+       if (cp_list) {
+           _invlist_union(cp_list, depends_list, &cp_list);
+           SvREFCNT_dec(depends_list);
        }
        else {
-           /* 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);
-
-           /* Any swash can't be used as-is, because we've inverted things */
-           if (swash) {
-               SvREFCNT_dec(swash);
-               swash = NULL;
-           }
-
-           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, 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);
-               }
-           }
-           else {
-               /* There is no overlap for non-/d, so just delete anything
-                * below 256 */
-               _invlist_intersection(nonbitmap, PL_AboveLatin1, &nonbitmap);
-           }
+           cp_list = depends_list;
        }
-
-       stored = 256 - stored;
-
-       /* Clear the invert flag since have just done it here */
-       ANYOF_FLAGS(ret) &= ~ANYOF_INVERT;
     }
 
     /* Folding in the bitmap is taken care of above, but not for locale (for
@@ -12072,7 +12423,7 @@ parseit:
      * run-time fold flag for these */
     if (FOLD && (LOC
                || (DEPENDS_SEMANTICS
-                   && nonbitmap
+                   && cp_list
                    && ! (ANYOF_FLAGS(ret) & ANYOF_NONBITMAP_NON_UTF8))
                || unicode_alternate))
     {
@@ -12093,9 +12444,9 @@ parseit:
      * characters which only have the two folds; so things like 'fF' and 'Ii'
      * wouldn't work because they are part of the fold of 'LATIN SMALL LIGATURE
      * FI'. */
-    if (! nonbitmap
+    if (! cp_list
        && ! unicode_alternate
-       && SvCUR(listsv) == initial_listsv_len
+       && ! HAS_NONLOCALE_RUNTIME_PROPERTY_DEFINITION
        && ! (ANYOF_FLAGS(ret) & (ANYOF_INVERT|ANYOF_UNICODE_ALL))
         && (((stored == 1 && ((! (ANYOF_FLAGS(ret) & ANYOF_LOCALE))
                               || (! ANYOF_CLASS_TEST_ANY_SET(ret)))))
@@ -12103,7 +12454,7 @@ parseit:
                                 && (! _HAS_NONLATIN1_FOLD_CLOSURE_ONLY_FOR_USE_BY_REGCOMP_DOT_C_AND_REGEXEC_DOT_C(value))
                                 /* If the latest code point has a fold whose
                                  * bit is set, it must be the only other one */
-                               && ((prevvalue = PL_fold_latin1[value]) != (IV)value)
+                               && ((prevvalue = PL_fold_latin1[value]) != value)
                                 && ANYOF_BITMAP_TEST(ret, prevvalue)))))
     {
         /* Note that the information needed to decide to do this optimization
@@ -12146,7 +12497,7 @@ parseit:
             * 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)) {
+           if (ASCII_FOLD_RESTRICTED && isASCII(value)) {
                op = EXACTFA;
            }
            else if (AT_LEAST_UNI_SEMANTICS || !isASCII(value)) {
@@ -12180,8 +12531,8 @@ parseit:
        SvREFCNT_dec(swash);
        swash = NULL;
     }
-    if (! nonbitmap
-       && SvCUR(listsv) == initial_listsv_len
+    if (! cp_list
+       && ! HAS_NONLOCALE_RUNTIME_PROPERTY_DEFINITION
        && ! unicode_alternate)
     {
        ARG_SET(ret, ANYOF_NONBITMAP_EMPTY);
@@ -12197,24 +12548,24 @@ parseit:
         *       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[3] stores the cp_list inversion list for use in addition or
+        *       instead of av[0]; used only if av[1] is 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 */
+        *       property; used only if av[1] is NULL */
        AV * const av = newAV();
        SV *rv;
 
-       av_store(av, 0, (SvCUR(listsv) == initial_listsv_len)
-                       ? &PL_sv_undef
-                       : listsv);
+       av_store(av, 0, (HAS_NONLOCALE_RUNTIME_PROPERTY_DEFINITION)
+                       ? listsv
+                       : &PL_sv_undef);
        if (swash) {
            av_store(av, 1, swash);
-           SvREFCNT_dec(nonbitmap);
+           SvREFCNT_dec(cp_list);
        }
        else {
            av_store(av, 1, NULL);
-           if (nonbitmap) {
-               av_store(av, 3, nonbitmap);
+           if (cp_list) {
+               av_store(av, 3, cp_list);
                av_store(av, 4, newSVuv(has_user_defined_property));
            }
        }
@@ -12237,6 +12588,7 @@ parseit:
     }
     return ret;
 }
+#undef HAS_NONLOCALE_RUNTIME_PROPERTY_DEFINITION
 
 
 /* reg_skipcomment()
@@ -12830,6 +13182,40 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
 #ifdef DEBUGGING
     dVAR;
     register int k;
+
+    /* Should be synchronized with * ANYOF_ #xdefines in regcomp.h */
+    static const char * const anyofs[] = {
+        "\\w",
+        "\\W",
+        "\\s",
+        "\\S",
+        "\\d",
+        "\\D",
+        "[:alnum:]",
+        "[:^alnum:]",
+        "[:alpha:]",
+        "[:^alpha:]",
+        "[:ascii:]",
+        "[:^ascii:]",
+        "[:cntrl:]",
+        "[:^cntrl:]",
+        "[:graph:]",
+        "[:^graph:]",
+        "[:lower:]",
+        "[:^lower:]",
+        "[:print:]",
+        "[:^print:]",
+        "[:punct:]",
+        "[:^punct:]",
+        "[:upper:]",
+        "[:^upper:]",
+        "[:xdigit:]",
+        "[:^xdigit:]",
+        "[:space:]",
+        "[:^space:]",
+        "[:blank:]",
+        "[:^blank:]"
+    };
     RXi_GET_DECL(prog,progi);
     GET_RE_DEBUG_FLAGS_DECL;
     
@@ -12950,39 +13336,6 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
        const U8 flags = ANYOF_FLAGS(o);
        int do_sep = 0;
 
-       /* Should be synchronized with * ANYOF_ #xdefines in regcomp.h */
-       static const char * const anyofs[] = {
-           "\\w",
-           "\\W",
-           "\\s",
-           "\\S",
-           "\\d",
-           "\\D",
-           "[:alnum:]",
-           "[:^alnum:]",
-           "[:alpha:]",
-           "[:^alpha:]",
-           "[:ascii:]",
-           "[:^ascii:]",
-           "[:cntrl:]",
-           "[:^cntrl:]",
-           "[:graph:]",
-           "[:^graph:]",
-           "[:lower:]",
-           "[:^lower:]",
-           "[:print:]",
-           "[:^print:]",
-           "[:punct:]",
-           "[:^punct:]",
-           "[:upper:]",
-           "[:^upper:]",
-           "[:xdigit:]",
-           "[:^xdigit:]",
-           "[:space:]",
-           "[:^space:]",
-           "[:blank:]",
-           "[:^blank:]"
-       };
 
        if (flags & ANYOF_LOCALE)
            sv_catpvs(sv, "{loc}");
@@ -13230,7 +13583,6 @@ Perl_reg_temp_copy (pTHX_ REGEXP *ret_x, REGEXP *rx)
 {
     struct regexp *ret;
     struct regexp *const r = (struct regexp *)SvANY(rx);
-    register const I32 npar = r->nparens+1;
 
     PERL_ARGS_ASSERT_REG_TEMP_COPY;
 
@@ -13250,8 +13602,11 @@ Perl_reg_temp_copy (pTHX_ REGEXP *ret_x, REGEXP *rx)
     SvLEN_set(ret_x, 0);
     SvSTASH_set(ret_x, NULL);
     SvMAGIC_set(ret_x, NULL);
-    Newx(ret->offs, npar, regexp_paren_pair);
-    Copy(r->offs, ret->offs, npar, regexp_paren_pair);
+    if (r->offs) {
+        const I32 npar = r->nparens+1;
+        Newx(ret->offs, npar, regexp_paren_pair);
+        Copy(r->offs, ret->offs, npar, regexp_paren_pair);
+    }
     if (r->substrs) {
         Newx(ret->substrs, 1, struct reg_substr_data);
        StructCopy(r->substrs, ret->substrs, struct reg_substr_data);
@@ -13321,9 +13676,6 @@ Perl_regfree_internal(pTHX_ REGEXP * const rx)
 
     if (ri->data) {
        int n = ri->data->count;
-       PAD* new_comppad = NULL;
-       PAD* old_comppad;
-       PADOFFSET refcnt;
 
        while (--n >= 0) {
           /* If you add a ->what type here, update the comment in regcomp.h */
@@ -13338,29 +13690,8 @@ Perl_regfree_internal(pTHX_ REGEXP * const rx)
            case 'f':
                Safefree(ri->data->data[n]);
                break;
-           case 'p':
-               new_comppad = MUTABLE_AV(ri->data->data[n]);
-               break;
-           case 'o':
-               if (new_comppad == NULL)
-                   Perl_croak(aTHX_ "panic: pregfree comppad");
-               PAD_SAVE_LOCAL(old_comppad,
-                   /* Watch out for global destruction's random ordering. */
-                   (SvTYPE(new_comppad) == SVt_PVAV) ? new_comppad : NULL
-               );
-               OP_REFCNT_LOCK;
-               refcnt = OpREFCNT_dec((OP_4tree*)ri->data->data[n]);
-               OP_REFCNT_UNLOCK;
-               if (!refcnt)
-                    op_free((OP_4tree*)ri->data->data[n]);
-
-               PAD_RESTORE_LOCAL(old_comppad);
-               SvREFCNT_dec(MUTABLE_SV(new_comppad));
-               new_comppad = NULL;
-               break;
            case 'l':
            case 'L':
-           case 'n':
                break;
             case 'T':          
                 { /* Aho Corasick add-on structure for a trie node.
@@ -13579,13 +13910,11 @@ Perl_regdupe_internal(pTHX_ REGEXP * const rx, CLONE_PARAMS *param)
        for (i = 0; i < count; i++) {
            d->what[i] = ri->data->what[i];
            switch (d->what[i]) {
-               /* legal options are one of: sSfpontTua
-                  see also regcomp.h and pregfree() */
+               /* see also regcomp.h and regfree_internal() */
            case 'a': /* actually an AV, but the dup function is identical.  */
            case 'r':
            case 's':
            case 'S':
-           case 'p': /* actually an AV, but the dup function is identical.  */
            case 'u': /* actually an HV, but the dup function is identical.  */
                d->data[i] = sv_dup_inc((const SV *)ri->data->data[i], param);
                break;
@@ -13596,13 +13925,6 @@ Perl_regdupe_internal(pTHX_ REGEXP * const rx, CLONE_PARAMS *param)
                            struct regnode_charclass_class);
                reti->regstclass = (regnode*)d->data[i];
                break;
-           case 'o':
-               /* Compiled op trees are readonly and in shared memory,
-                  and can thus be shared without duplication. */
-               OP_REFCNT_LOCK;
-               d->data[i] = (void*)OpREFCNT_inc((OP*)ri->data->data[i]);
-               OP_REFCNT_UNLOCK;
-               break;
            case 'T':
                /* Trie stclasses are readonly and can thus be shared
                 * without duplication. We free the stclass in pregfree
@@ -13617,7 +13939,6 @@ Perl_regdupe_internal(pTHX_ REGEXP * const rx, CLONE_PARAMS *param)
                /* Fall through */
            case 'l':
            case 'L':
-           case 'n':
                d->data[i] = ri->data->data[i];
                break;
             default:
@@ -13727,8 +14048,6 @@ Perl_save_re_context(pTHX)
 
     Copy(&PL_reg_state, state, 1, struct re_save_state);
 
-    PL_reg_start_tmp = 0;
-    PL_reg_start_tmpl = 0;
     PL_reg_oldsaved = NULL;
     PL_reg_oldsavedlen = 0;
     PL_reg_maxiter = 0;