X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/4ae2f9814731932908f61ce4a79c6da6063584e7..dad790286e318c5c7f4b6ccd52b4fd512c87c763:/regexec.c

diff --git a/regexec.c b/regexec.c
index 4aa27f8..890736c 100644
--- a/regexec.c
+++ b/regexec.c
@@ -839,7 +839,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 		   : strend);
 
 	t = s;
-        s = find_byclass(prog, prog->regstclass, s, endpos, 1);
+        s = find_byclass(prog, prog->regstclass, s, endpos, NULL);
 	if (!s) {
 #ifdef DEBUGGING
 	    const char *what = NULL;
@@ -931,8 +931,11 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 }
 
 /* We know what class REx starts with.  Try to find this position... */
+/* if reginfo is NULL, its a dryrun */
+
 STATIC char *
-S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *strend, I32 norun)
+S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char
+*strend, const regmatch_info *reginfo)
 {
 	dVAR;
 	const I32 doevery = (prog->reganch & ROPT_SKIP) == 0;
@@ -955,7 +958,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 			  !UTF8_IS_INVARIANT((U8)s[0]) ?
 			  reginclass(prog, c, (U8*)s, 0, do_utf8) :
 			  REGINCLASS(prog, c, (U8*)s)) {
-			   if (tmp && (norun || regtry(prog, s)))
+			   if (tmp && (!reginfo || regtry(reginfo, s)))
 				goto got_it;
 			   else
 				tmp = doevery;
@@ -974,7 +977,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 			   /* The assignment of 2 is intentional:
 			    * for the folded sharp s, the skip is 2. */
 			   (skip = SHARP_S_SKIP))) {
-			   if (tmp && (norun || regtry(prog, s)))
+			   if (tmp && (!reginfo || regtry(reginfo, s)))
 				goto got_it;
 			   else
 				tmp = doevery;
@@ -987,7 +990,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    break;
 	case CANY:
 	    while (s < strend) {
-	        if (tmp && (norun || regtry(prog, s)))
+	        if (tmp && (!reginfo || regtry(reginfo, s)))
 		    goto got_it;
 		else
 		    tmp = doevery;
@@ -1032,7 +1035,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	  do_exactf:
 	    e = HOP3c(strend, -((I32)lnc), s);
 
-	    if (norun && e < s)
+	    if (!reginfo && e < s)
 		e = s;			/* Due to minlen logic of intuit() */
 
 	    /* The idea in the EXACTF* cases is to first find the
@@ -1061,7 +1064,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 			     && (ln == len ||
 				 ibcmp_utf8(s, (char **)0, 0,  do_utf8,
 					    m, (char **)0, ln, (bool)UTF))
-			     && (norun || regtry(prog, s)) )
+			     && (!reginfo || regtry(reginfo, s)) )
 			    goto got_it;
 			else {
 			     U8 foldbuf[UTF8_MAXBYTES_CASE+1];
@@ -1074,7 +1077,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 						  (char **)0, foldlen, do_utf8,
 						  m,
 						  (char **)0, ln, (bool)UTF))
-				  && (norun || regtry(prog, s)) )
+				  && (!reginfo || regtry(reginfo, s)) )
 				  goto got_it;
 			}
 			s += len;
@@ -1100,7 +1103,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 			     && (ln == len ||
 				 ibcmp_utf8(s, (char **)0, 0,  do_utf8,
 					    m, (char **)0, ln, (bool)UTF))
-			     && (norun || regtry(prog, s)) )
+			     && (!reginfo || regtry(reginfo, s)) )
 			    goto got_it;
 			else {
 			     U8 foldbuf[UTF8_MAXBYTES_CASE+1];
@@ -1113,7 +1116,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 						  (char **)0, foldlen, do_utf8,
 						  m,
 						  (char **)0, ln, (bool)UTF))
-				  && (norun || regtry(prog, s)) )
+				  && (!reginfo || regtry(reginfo, s)) )
 				  goto got_it;
 			}
 			s += len;
@@ -1127,7 +1130,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 			     && (ln == 1 || !(OP(c) == EXACTF
 					      ? ibcmp(s, m, ln)
 					      : ibcmp_locale(s, m, ln)))
-			     && (norun || regtry(prog, s)) )
+			     && (!reginfo || regtry(reginfo, s)) )
 			    goto got_it;
 			s++;
 		    }
@@ -1137,7 +1140,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 			     && (ln == 1 || !(OP(c) == EXACTF
 					      ? ibcmp(s, m, ln)
 					      : ibcmp_locale(s, m, ln)))
-			     && (norun || regtry(prog, s)) )
+			     && (!reginfo || regtry(reginfo, s)) )
 			    goto got_it;
 			s++;
 		    }
@@ -1163,7 +1166,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 				 isALNUM_LC_utf8((U8*)s)))
 		    {
 			tmp = !tmp;
-			if ((norun || regtry(prog, s)))
+			if ((!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 		    }
 		    s += uskip;
@@ -1176,13 +1179,13 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 		    if (tmp ==
 			!(OP(c) == BOUND ? isALNUM(*s) : isALNUM_LC(*s))) {
 			tmp = !tmp;
-			if ((norun || regtry(prog, s)))
+			if ((!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 		    }
 		    s++;
 		}
 	    }
-	    if ((!prog->minlen && tmp) && (norun || regtry(prog, s)))
+	    if ((!prog->minlen && tmp) && (!reginfo || regtry(reginfo, s)))
 		goto got_it;
 	    break;
 	case NBOUNDL:
@@ -1204,7 +1207,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 				 swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8) :
 				 isALNUM_LC_utf8((U8*)s)))
 			tmp = !tmp;
-		    else if ((norun || regtry(prog, s)))
+		    else if ((!reginfo || regtry(reginfo, s)))
 			goto got_it;
 		    s += uskip;
 		}
@@ -1217,12 +1220,12 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 		    if (tmp ==
 			!(OP(c) == NBOUND ? isALNUM(*s) : isALNUM_LC(*s)))
 			tmp = !tmp;
-		    else if ((norun || regtry(prog, s)))
+		    else if ((!reginfo || regtry(reginfo, s)))
 			goto got_it;
 		    s++;
 		}
 	    }
-	    if ((!prog->minlen && !tmp) && (norun || regtry(prog, s)))
+	    if ((!prog->minlen && !tmp) && (!reginfo || regtry(reginfo, s)))
 		goto got_it;
 	    break;
 	case ALNUM:
@@ -1230,7 +1233,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 		LOAD_UTF8_CHARCLASS_ALNUM();
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1243,7 +1246,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (isALNUM(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1259,7 +1262,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    if (do_utf8) {
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (isALNUM_LC_utf8((U8*)s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1272,7 +1275,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (isALNUM_LC(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1288,7 +1291,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 		LOAD_UTF8_CHARCLASS_ALNUM();
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (!swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1301,7 +1304,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (!isALNUM(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1317,7 +1320,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    if (do_utf8) {
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (!isALNUM_LC_utf8((U8*)s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1330,7 +1333,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (!isALNUM_LC(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1346,7 +1349,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 		LOAD_UTF8_CHARCLASS_SPACE();
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (*s == ' ' || swash_fetch(PL_utf8_space,(U8*)s, do_utf8)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1359,7 +1362,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (isSPACE(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1375,7 +1378,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    if (do_utf8) {
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (*s == ' ' || isSPACE_LC_utf8((U8*)s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1388,7 +1391,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (isSPACE_LC(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1404,7 +1407,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 		LOAD_UTF8_CHARCLASS_SPACE();
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (!(*s == ' ' || swash_fetch(PL_utf8_space,(U8*)s, do_utf8))) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1417,7 +1420,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (!isSPACE(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1433,7 +1436,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    if (do_utf8) {
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (!(*s == ' ' || isSPACE_LC_utf8((U8*)s))) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1446,7 +1449,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (!isSPACE_LC(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1462,7 +1465,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 		LOAD_UTF8_CHARCLASS_DIGIT();
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (swash_fetch(PL_utf8_digit,(U8*)s, do_utf8)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1475,7 +1478,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (isDIGIT(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1491,7 +1494,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    if (do_utf8) {
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (isDIGIT_LC_utf8((U8*)s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1504,7 +1507,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (isDIGIT_LC(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1520,7 +1523,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 		LOAD_UTF8_CHARCLASS_DIGIT();
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (!swash_fetch(PL_utf8_digit,(U8*)s, do_utf8)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1533,7 +1536,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (!isDIGIT(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1549,7 +1552,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    if (do_utf8) {
 		while (s + (uskip = UTF8SKIP(s)) <= strend) {
 		    if (!isDIGIT_LC_utf8((U8*)s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1562,7 +1565,7 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s, const char *stren
 	    else {
 		while (s < strend) {
 		    if (!isDIGIT_LC(*s)) {
-			if (tmp && (norun || regtry(prog, s)))
+			if (tmp && (!reginfo || regtry(reginfo, s)))
 			    goto got_it;
 			else
 			    tmp = doevery;
@@ -1610,6 +1613,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
     SV* dsv0;
     SV* dsv1;
 #endif
+    regmatch_info reginfo;  /* create some info to pass to regtry etc */
 
     GET_RE_DEBUG_FLAGS_DECL;
 
@@ -1622,16 +1626,13 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
     }
 
     multiline = prog->reganch & PMf_MULTILINE;
+    reginfo.prog = prog;
 
 #ifdef DEBUGGING
     dsv0 = PERL_DEBUG_PAD_ZERO(0);
     dsv1 = PERL_DEBUG_PAD_ZERO(1);
 #endif
 
-#ifdef DEBUGGING
-    PL_regnarrate = DEBUG_r_TEST;
-#endif
-
     RX_MATCH_UTF8_set(prog, do_utf8);
 
     minlen = prog->minlen;
@@ -1654,37 +1655,37 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 	PL_reg_flags |= RF_utf8;
 
     /* Mark beginning of line for ^ and lookbehind. */
-    PL_regbol = startpos;
+    reginfo.bol = startpos; /* XXX not used ??? */
     PL_bostr  = strbeg;
-    PL_reg_sv = sv;
+    reginfo.sv = sv;
 
     /* Mark end of line for $ (and such) */
     PL_regeol = strend;
 
     /* see how far we have to get to not match where we matched before */
-    PL_regtill = startpos+minend;
+    reginfo.till = startpos+minend;
 
     /* If there is a "must appear" string, look for it. */
     s = startpos;
 
-    if (prog->reganch & ROPT_GPOS_SEEN) { /* Need to have PL_reg_ganch */
+    if (prog->reganch & ROPT_GPOS_SEEN) { /* Need to set reginfo->ganch */
 	MAGIC *mg;
 
 	if (flags & REXEC_IGNOREPOS)	/* Means: check only at start */
-	    PL_reg_ganch = startpos;
+	    reginfo.ganch = startpos;
 	else if (sv && SvTYPE(sv) >= SVt_PVMG
 		  && SvMAGIC(sv)
 		  && (mg = mg_find(sv, PERL_MAGIC_regex_global))
 		  && mg->mg_len >= 0) {
-	    PL_reg_ganch = strbeg + mg->mg_len;	/* Defined pos() */
+	    reginfo.ganch = strbeg + mg->mg_len;	/* Defined pos() */
 	    if (prog->reganch & ROPT_ANCH_GPOS) {
-	        if (s > PL_reg_ganch)
+	        if (s > reginfo.ganch)
 		    goto phooey;
-		s = PL_reg_ganch;
+		s = reginfo.ganch;
 	    }
 	}
 	else				/* pos() not defined */
-	    PL_reg_ganch = strbeg;
+	    reginfo.ganch = strbeg;
     }
 
     if (!(flags & REXEC_CHECKED) && (prog->check_substr != NULL || prog->check_utf8 != NULL)) {
@@ -1726,7 +1727,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
     /* Simplest case:  anchored match need be tried only once. */
     /*  [unless only anchor is BOL and multiline is set] */
     if (prog->reganch & (ROPT_ANCH & ~ROPT_ANCH_GPOS)) {
-	if (s == startpos && regtry(prog, startpos))
+	if (s == startpos && regtry(&reginfo, startpos))
 	    goto got_it;
 	else if (multiline || (prog->reganch & ROPT_IMPLICIT)
 		 || (prog->reganch & ROPT_ANCH_MBOL)) /* XXXX SBOL? */
@@ -1741,7 +1742,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 		if (s == startpos)
 		    goto after_try;
 		while (1) {
-		    if (regtry(prog, s))
+		    if (regtry(&reginfo, s))
 			goto got_it;
 		  after_try:
 		    if (s >= end)
@@ -1759,7 +1760,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 		    s--;
 		while (s < end) {
 		    if (*s++ == '\n') {	/* don't need PL_utf8skip here */
-			if (regtry(prog, s))
+			if (regtry(&reginfo, s))
 			    goto got_it;
 		    }
 		}		
@@ -1767,7 +1768,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 	}
 	goto phooey;
     } else if (prog->reganch & ROPT_ANCH_GPOS) {
-	if (regtry(prog, PL_reg_ganch))
+	if (regtry(&reginfo, reginfo.ganch))
 	    goto got_it;
 	goto phooey;
     }
@@ -1788,7 +1789,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 	    while (s < strend) {
 		if (*s == ch) {
 		    DEBUG_EXECUTE_r( did_match = 1 );
-		    if (regtry(prog, s)) goto got_it;
+		    if (regtry(&reginfo, s)) goto got_it;
 		    s += UTF8SKIP(s);
 		    while (s < strend && *s == ch)
 			s += UTF8SKIP(s);
@@ -1800,7 +1801,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 	    while (s < strend) {
 		if (*s == ch) {
 		    DEBUG_EXECUTE_r( did_match = 1 );
-		    if (regtry(prog, s)) goto got_it;
+		    if (regtry(&reginfo, s)) goto got_it;
 		    s++;
 		    while (s < strend && *s == ch)
 			s++;
@@ -1878,14 +1879,14 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 	    }
 	    if (do_utf8) {
 		while (s <= last1) {
-		    if (regtry(prog, s))
+		    if (regtry(&reginfo, s))
 			goto got_it;
 		    s += UTF8SKIP(s);
 		}
 	    }
 	    else {
 		while (s <= last1) {
-		    if (regtry(prog, s))
+		    if (regtry(&reginfo, s))
 			goto got_it;
 		    s++;
 		}
@@ -1931,7 +1932,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 			  len0, len0, s0,
 			  len1, len1, s1);
 	});
-        if (find_byclass(prog, c, s, strend, 0))
+        if (find_byclass(prog, c, s, strend, &reginfo))
 	    goto got_it;
 	DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Contradicts stclass...\n"));
     }
@@ -1989,7 +1990,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 	/* We don't know much -- general case. */
 	if (do_utf8) {
 	    for (;;) {
-		if (regtry(prog, s))
+		if (regtry(&reginfo, s))
 		    goto got_it;
 		if (s >= strend)
 		    break;
@@ -1998,7 +1999,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 	}
 	else {
 	    do {
-		if (regtry(prog, s))
+		if (regtry(&reginfo, s))
 		    goto got_it;
 	    } while (s++ < strend);
 	}
@@ -2064,12 +2065,13 @@ phooey:
  - regtry - try match at specific point
  */
 STATIC I32			/* 0 failure, 1 success */
-S_regtry(pTHX_ regexp *prog, char *startpos)
+S_regtry(pTHX_ const regmatch_info *reginfo, char *startpos)
 {
     dVAR;
     register I32 *sp;
     register I32 *ep;
     CHECKPOINT lastcp;
+    regexp *prog = reginfo->prog;
     GET_RE_DEBUG_FLAGS_DECL;
 
 #ifdef DEBUGGING
@@ -2091,21 +2093,21 @@ S_regtry(pTHX_ regexp *prog, char *startpos)
 	/* SAVEI8(cxstack[cxstack_ix].blk_gimme);
 	   cxstack[cxstack_ix].blk_gimme = G_SCALAR; */
 
-	if (PL_reg_sv) {
+	if (reginfo->sv) {
 	    /* Make $_ available to executed code. */
-	    if (PL_reg_sv != DEFSV) {
+	    if (reginfo->sv != DEFSV) {
 		SAVE_DEFSV;
-		DEFSV = PL_reg_sv;
+		DEFSV = reginfo->sv;
 	    }
 	
-	    if (!(SvTYPE(PL_reg_sv) >= SVt_PVMG && SvMAGIC(PL_reg_sv)
-		  && (mg = mg_find(PL_reg_sv, PERL_MAGIC_regex_global)))) {
+	    if (!(SvTYPE(reginfo->sv) >= SVt_PVMG && SvMAGIC(reginfo->sv)
+		  && (mg = mg_find(reginfo->sv, PERL_MAGIC_regex_global)))) {
 		/* prepare for quick setting of pos */
 #ifdef PERL_OLD_COPY_ON_WRITE
 		if (SvIsCOW(sv))
 		    sv_force_normal_flags(sv, 0);
 #endif
-		mg = sv_magicext(PL_reg_sv, (SV*)0, PERL_MAGIC_regex_global,
+		mg = sv_magicext(reginfo->sv, (SV*)0, PERL_MAGIC_regex_global,
 				 &PL_vtbl_mglob, NULL, 0);
 		mg->mg_len = -1;
 	    }
@@ -2189,7 +2191,7 @@ S_regtry(pTHX_ regexp *prog, char *startpos)
     }
 #endif
     REGCP_SET(lastcp);
-    if (regmatch(prog, prog->program + 1)) {
+    if (regmatch(reginfo, prog->program + 1)) {
 	prog->endp[0] = PL_reginput - PL_bostr;
 	return 1;
     }
@@ -2232,7 +2234,6 @@ typedef union re_unwind_t {
 #define sayNO goto no
 #define sayNO_ANYOF goto no_anyof
 #define sayYES_FINAL goto yes_final
-#define sayYES_LOUD  goto yes_loud
 #define sayNO_FINAL  goto no_final
 #define sayNO_SILENT goto do_no
 #define saySAME(x) if (x) goto yes; else goto no
@@ -2240,11 +2241,17 @@ typedef union re_unwind_t {
 #define POSCACHE_SUCCESS 0	/* caching success rather than failure */
 #define POSCACHE_SEEN 1		/* we know what we're caching */
 #define POSCACHE_START 2	/* the real cache: this bit maps to pos 0 */
+
 #define CACHEsayYES STMT_START { \
     if (st->u.whilem.cache_offset | st->u.whilem.cache_bit) { \
-	if (!(PL_reg_poscache[0] & (1<<POSCACHE_SEEN))) \
-	    PL_reg_poscache[0] |= (1<<POSCACHE_SUCCESS) || (1<<POSCACHE_SEEN); \
-        else if (!(PL_reg_poscache[0] & (1<<POSCACHE_SUCCESS))) { \
+	if (!(PL_reg_poscache[0] & (1<<POSCACHE_SEEN))) { \
+	    PL_reg_poscache[0] |= (1<<POSCACHE_SUCCESS) | (1<<POSCACHE_SEEN); \
+	    PL_reg_poscache[st->u.whilem.cache_offset] |= (1<<st->u.whilem.cache_bit); \
+	} \
+        else if (PL_reg_poscache[0] & (1<<POSCACHE_SUCCESS)) { \
+	    PL_reg_poscache[st->u.whilem.cache_offset] |= (1<<st->u.whilem.cache_bit); \
+	} \
+	else { \
 	    /* cache records failure, but this is success */ \
 	    DEBUG_r( \
 		PerlIO_printf(Perl_debug_log, \
@@ -2256,11 +2263,17 @@ typedef union re_unwind_t {
     } \
     sayYES; \
 } STMT_END
+
 #define CACHEsayNO STMT_START { \
     if (st->u.whilem.cache_offset | st->u.whilem.cache_bit) { \
-	if (!(PL_reg_poscache[0] & (1<<POSCACHE_SEEN))) \
+	if (!(PL_reg_poscache[0] & (1<<POSCACHE_SEEN))) { \
 	    PL_reg_poscache[0] |= (1<<POSCACHE_SEEN); \
-        else if ((PL_reg_poscache[0] & (1<<POSCACHE_SUCCESS))) { \
+	    PL_reg_poscache[st->u.whilem.cache_offset] |= (1<<st->u.whilem.cache_bit); \
+	} \
+        else if (!(PL_reg_poscache[0] & (1<<POSCACHE_SUCCESS))) { \
+	    PL_reg_poscache[st->u.whilem.cache_offset] |= (1<<st->u.whilem.cache_bit); \
+	} \
+	else { \
 	    /* cache records success, but this is failure */ \
 	    DEBUG_r( \
 		PerlIO_printf(Perl_debug_log, \
@@ -2285,6 +2298,9 @@ typedef union re_unwind_t {
 /* Make sure there is a test for this +1 options in re_tests */
 #define TRIE_INITAL_ACCEPT_BUFFLEN 4;
 
+#define SLAB_FIRST(s) (&(s)->states[0])
+#define SLAB_LAST(s)  (&(s)->states[PERL_REGMATCH_SLAB_SLOTS-1])
+
 /* grab a new slab and return the first slot in it */
 
 STATIC regmatch_state *
@@ -2298,7 +2314,7 @@ S_push_slab(pTHX)
 	PL_regmatch_slab->next = s;
     }
     PL_regmatch_slab = s;
-    return &s->states[0];
+    return SLAB_FIRST(s);
 }
 
 /* simulate a recursive call to regmatch */
@@ -2322,7 +2338,7 @@ S_push_slab(pTHX)
     st->locinput = locinput;	\
     st->resume_state = resume;	\
     newst = st+1;   \
-    if (newst >  &(PL_regmatch_slab->states[PERL_REGMATCH_SLAB_SLOTS-1])) \
+    if (newst >  SLAB_LAST(PL_regmatch_slab)) \
 	newst = S_push_slab(aTHX);  \
     PL_regmatch_state = newst;	\
     newst->cc = 0;  \
@@ -2337,9 +2353,9 @@ S_push_slab(pTHX)
     DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "POP STATE(%d)\n", depth)); \
     depth--; \
     st--; \
-    if (st < &PL_regmatch_slab->states[0]) { \
+    if (st < SLAB_FIRST(PL_regmatch_slab)) { \
 	PL_regmatch_slab = PL_regmatch_slab->prev; \
-	st = &PL_regmatch_slab->states[PERL_REGMATCH_SLAB_SLOTS-1]; \
+	st = SLAB_LAST(PL_regmatch_slab); \
     } \
     PL_regmatch_state = st; \
     scan	= st->scan; \
@@ -2455,12 +2471,14 @@ S_push_slab(pTHX)
  
 
 STATIC I32			/* 0 failure, 1 success */
-S_regmatch(pTHX_ regexp *rex, regnode *prog)
+S_regmatch(pTHX_ const regmatch_info *reginfo, regnode *prog)
 {
     dVAR;
     register const bool do_utf8 = PL_reg_match_utf8;
     const U32 uniflags = UTF8_ALLOW_DEFAULT;
 
+    regexp *rex = reginfo->prog;
+
     regmatch_slab  *orig_slab;
     regmatch_state *orig_state;
 
@@ -2479,7 +2497,8 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
     regnode *inner;	    /* Next node in internal branch. */
     int depth = 0;	    /* depth of recursion */
     regmatch_state *newst;  /* when pushing a state, this is the new one */
-    regmatch_state *cur_eval = NULL;  /* most recent (??{}) state */
+    regmatch_state *yes_state = NULL; /* state to pop to on success of
+							    subpattern */
     
 #ifdef DEBUGGING
     SV *re_debug_flags = NULL;
@@ -2492,7 +2511,7 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 	Newx(PL_regmatch_slab, 1, regmatch_slab);
 	PL_regmatch_slab->prev = NULL;
 	PL_regmatch_slab->next = NULL;
-	PL_regmatch_state = &PL_regmatch_slab->states[0] - 1;
+	PL_regmatch_state = SLAB_FIRST(PL_regmatch_slab);
     }
 
     /* remember current high-water mark for exit */
@@ -2502,7 +2521,7 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 
     /* grab next free state slot */
     st = ++PL_regmatch_state;
-    if (st >  &(PL_regmatch_slab->states[PERL_REGMATCH_SLAB_SLOTS-1]))
+    if (st >  SLAB_LAST(PL_regmatch_slab))
 	st = PL_regmatch_state = S_push_slab(aTHX);
 
     st->minmod = 0;
@@ -2589,7 +2608,7 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 	case BOL:
 	    if (locinput == PL_bostr)
 	    {
-		/* regtill = regbol; */
+		/* reginfo->till = reginfo->bol; */
 		break;
 	    }
 	    sayNO;
@@ -2605,7 +2624,7 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 		break;
 	    sayNO;
 	case GPOS:
-	    if (locinput == PL_reg_ganch)
+	    if (locinput == reginfo->ganch)
 		break;
 	    sayNO;
 	case EOL:
@@ -3395,10 +3414,9 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 		st->u.eval.prev_rex = rex;
 		rex = re;
 
-		st->u.eval.prev_eval = cur_eval;
-		st->u.eval.prev_slab = PL_regmatch_slab;
-		st->u.eval.depth = depth;
-		cur_eval = st;
+		/* resume to current state on success */
+		st->u.yes.prev_yes_state = yes_state;
+		yes_state = st;
 		PUSH_STATE(newst, resume_EVAL);
 		st = newst;
 
@@ -3524,7 +3542,19 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 		/* No need to save/restore up to this paren */
 		I32 parenfloor = scan->flags;
 
-		if (next && (OP(PREVOPER(next)) == NOTHING)) /* LONGJMP */
+		/* Dave says:
+		   
+		   CURLYX and WHILEM are always paired: they're the moral
+		   equivalent of pp_enteriter anbd pp_iter.
+
+		   The only time next could be null is if the node tree is
+		   corrupt. This was mentioned on p5p a few days ago.
+
+		   See http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-04/msg00556.html
+		   So we'll assert that this is true:
+		*/
+		assert(next);
+		if (OP(PREVOPER(next)) == NOTHING) /* LONGJMP */
 		    next += ARG(next);
 		/* XXXX Probably it is better to teach regpush to support
 		   parenfloor > PL_regsize... */
@@ -3563,6 +3593,16 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 		 * that we can try again after backing off.
 		 */
 
+		/* Dave says:
+
+		   st->cc gets initialised by CURLYX ready for use by WHILEM.
+		   So again, unless somethings been corrupted, st->cc cannot
+		   be null at that point in WHILEM.
+		   
+		   See http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-04/msg00556.html
+		   So we'll assert that this is true:
+		*/
+		assert(st->cc);
 		st->u.whilem.lastloc = st->cc->u.curlyx.lastloc; /* Detection of 0-len. */
 		st->u.whilem.cache_offset = 0;
 		st->u.whilem.cache_bit = 0;
@@ -3661,7 +3701,6 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 			    /* cache records failure */
 			    sayNO_SILENT;
 		    }
-		    PL_reg_poscache[st->u.whilem.cache_offset] |= (1<<st->u.whilem.cache_bit);
 		}
 		}
 
@@ -3835,7 +3874,11 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 	    st->u.curlym.maxwanted = st->minmod ? st->ln : n;
 	    if (st->u.curlym.maxwanted) {
 		while (PL_reginput < PL_regeol && st->u.curlym.matches < st->u.curlym.maxwanted) {
+		    /* resume to current state on success */
+		    st->u.yes.prev_yes_state = yes_state;
+		    yes_state = st;
 		    REGMATCH(scan, CURLYM1);
+		    yes_state = st->u.yes.prev_yes_state;
 		    /*** all unsaved local vars undefined at this point */
 		    if (!result)
 			break;
@@ -3905,15 +3948,24 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 			    else
 				PL_regendp[st->u.curlym.paren] = -1;
 			}
+			/* resume to current state on success */
+			st->u.yes.prev_yes_state = yes_state;
+			yes_state = st;
 			REGMATCH(next, CURLYM2);
+			yes_state = st->u.yes.prev_yes_state;
 			/*** all unsaved local vars undefined at this point */
 			if (result)
-			    sayYES;
+			    /* XXX tmp sayYES; */
+			    sayYES_FINAL;
 			REGCP_UNWIND(st->u.curlym.lastcp);
 		    }
 		    /* Couldn't or didn't -- move forward. */
 		    PL_reginput = locinput;
+		    /* resume to current state on success */
+		    st->u.yes.prev_yes_state = yes_state;
+		    yes_state = st;
 		    REGMATCH(scan, CURLYM3);
+		    yes_state = st->u.yes.prev_yes_state;
 		    /*** all unsaved local vars undefined at this point */
 		    if (result) {
 			st->ln++;
@@ -3978,10 +4030,15 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 			    else
 				PL_regendp[st->u.curlym.paren] = -1;
 			}
+			/* resume to current state on success */
+			st->u.yes.prev_yes_state = yes_state;
+			yes_state = st;
 			REGMATCH(next, CURLYM4);
+			yes_state = st->u.yes.prev_yes_state;
 			/*** all unsaved local vars undefined at this point */
 			if (result)
-			    sayYES;
+			    /* XXX tmp sayYES; */
+			    sayYES_FINAL;
 			REGCP_UNWIND(st->u.curlym.lastcp);
 		    }
 		    /* Couldn't or didn't -- back up. */
@@ -4247,113 +4304,68 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 	    sayNO;
 	    break;
 	case END:
-	    if (cur_eval) {
-		/* we have successfully completed the execution of a
-		 * postponed re. Pop all states back to the last EVAL
-		 * then continue with the node following the (??{...})
-		 */
-
-		/* this simulates a POP_STATE, except that it pops several
-		 * levels, and doesn't restore locinput */
-
-		st = cur_eval;
-		PL_regmatch_slab = st->u.eval.prev_slab;
-		cur_eval = st->u.eval.prev_eval;
-		depth = st->u.eval.depth;
-
-		PL_regmatch_state = st;
-		scan	= st->scan;
-		next	= st->next;
-		n		= st->n;
-
-		if (st->u.eval.toggleutf)
-		    PL_reg_flags ^= RF_utf8;
-		ReREFCNT_dec(rex);
-		rex = st->u.eval.prev_rex;
-		/* XXXX This is too dramatic a measure... */
-		PL_reg_maxiter = 0;
-
-		/* Restore parens of the caller without popping the
-		 * savestack */
-		{
-		    I32 tmp = PL_savestack_ix;
-		    PL_savestack_ix = st->u.eval.lastcp;
-		    regcppop(rex);
-		    PL_savestack_ix = tmp;
-		}
-
-
-		PL_reginput = locinput;
-		/* resume at node following the (??{...}) */
-		break;
-
-	    }
-
-	    if (locinput < PL_regtill) {
+	    if (locinput < reginfo->till) {
 		DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
 				      "%sMatch possible, but length=%ld is smaller than requested=%ld, failing!%s\n",
 				      PL_colors[4],
 				      (long)(locinput - PL_reg_starttry),
-				      (long)(PL_regtill - PL_reg_starttry),
+				      (long)(reginfo->till - PL_reg_starttry),
 				      PL_colors[5]));
 		sayNO_FINAL;		/* Cannot match: too short. */
 	    }
 	    PL_reginput = locinput;	/* put where regtry can find it */
 	    sayYES_FINAL;		/* Success! */
-	case SUCCEED:
+
+	case SUCCEED: /* successful SUSPEND/UNLESSM/IFMATCH/CURLYM */
+	    DEBUG_EXECUTE_r(
+	    PerlIO_printf(Perl_debug_log,
+		"%*s  %ssubpattern success...%s\n",
+		REPORT_CODE_OFF+PL_regindent*2, "", PL_colors[4], PL_colors[5]));
 	    PL_reginput = locinput;	/* put where regtry can find it */
-	    sayYES_LOUD;		/* Success! */
-	case SUSPEND:
-	    n = 1;
+	    sayYES_FINAL;		/* Success! */
+
+	case SUSPEND:	/* (?>FOO) */
+	    st->u.ifmatch.wanted = 1;
 	    PL_reginput = locinput;
 	    goto do_ifmatch;	
-	case UNLESSM:
-	    n = 0;
-	    if (scan->flags) {
-		char * const s = HOPBACKc(locinput, scan->flags);
-		if (!s)
-		    goto say_yes;
-		PL_reginput = s;
-	    }
-	    else
-		PL_reginput = locinput;
-	    goto do_ifmatch;
-	case IFMATCH:
-	    n = 1;
+
+	case UNLESSM:	/* -ve lookaround: (?!FOO), or with flags, (?<!foo) */
+	    st->u.ifmatch.wanted = 0;
+	    goto ifmatch_trivial_fail_test;
+
+	case IFMATCH:	/* +ve lookaround: (?=FOO), or with flags, (?<=foo) */
+	    st->u.ifmatch.wanted = 1;
+	  ifmatch_trivial_fail_test:
 	    if (scan->flags) {
 		char * const s = HOPBACKc(locinput, scan->flags);
-		if (!s)
-		    goto say_no;
+		if (!s) {
+		    /* trivial fail */
+		    if (st->logical) {
+			st->logical = 0;
+			st->sw = 1 - st->u.ifmatch.wanted;
+		    }
+		    else if (st->u.ifmatch.wanted)
+			sayNO;
+		    next = scan + ARG(scan);
+		    if (next == scan)
+			next = NULL;
+		    break;
+		}
 		PL_reginput = s;
 	    }
 	    else
 		PL_reginput = locinput;
 
 	  do_ifmatch:
-	    REGMATCH(NEXTOPER(NEXTOPER(scan)), IFMATCH);
-	    /*** all unsaved local vars undefined at this point */
-	    if (result != n) {
-	      say_no:
-		if (st->logical) {
-		    st->logical = 0;
-		    st->sw = 0;
-		    goto do_longjump;
-		}
-		else
-		    sayNO;
-	    }
-	  say_yes:
-	    if (st->logical) {
-		st->logical = 0;
-		st->sw = 1;
-	    }
-	    if (OP(scan) == SUSPEND) {
-		locinput = PL_reginput;
-		nextchr = UCHARAT(locinput);
-	    }
-	    /* FALL THROUGH. */
+	    /* resume to current state on success */
+	    st->u.yes.prev_yes_state = yes_state;
+	    yes_state = st;
+	    PUSH_STATE(newst, resume_IFMATCH);
+	    st = newst;
+	    next = NEXTOPER(NEXTOPER(scan));
+	    break;
+
 	case LONGJMP:
-	  do_longjump:
 	    next = scan + ARG(scan);
 	    if (next == scan)
 		next = NULL;
@@ -4383,7 +4395,7 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
 
 	    /* grab the next free state slot */
 	    st++;
-	    if (st >  &(PL_regmatch_slab->states[PERL_REGMATCH_SLAB_SLOTS-1]))
+	    if (st >  SLAB_LAST(PL_regmatch_slab))
 		st = S_push_slab(aTHX);
 	    PL_regmatch_state = st;
 
@@ -4414,14 +4426,90 @@ S_regmatch(pTHX_ regexp *rex, regnode *prog)
     /*NOTREACHED*/
     sayNO;
 
-yes_loud:
-    DEBUG_EXECUTE_r(
-	PerlIO_printf(Perl_debug_log,
-		      "%*s  %scould match...%s\n",
-		      REPORT_CODE_OFF+PL_regindent*2, "", PL_colors[4], PL_colors[5])
-	);
-    goto yes;
 yes_final:
+
+    if (yes_state) {
+	/* we have successfully completed a subexpression, but we must now
+	 * pop to the state marked by yes_state and continue from there */
+
+	/*XXX tmp for CURLYM*/
+	regmatch_slab *oslab = PL_regmatch_slab;
+	regmatch_state *ost = st, *oys=yes_state;
+	int odepth = depth;
+
+	assert(st != yes_state);
+	while (yes_state < SLAB_FIRST(PL_regmatch_slab)
+	    || yes_state > SLAB_LAST(PL_regmatch_slab))
+	{
+	    /* not in this slab, pop slab */
+	    depth -= (st - SLAB_FIRST(PL_regmatch_slab) + 1);
+	    PL_regmatch_slab = PL_regmatch_slab->prev;
+	    st = SLAB_LAST(PL_regmatch_slab);
+	}
+	depth -= (st - yes_state);
+	DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "POP STATE TO (%d)\n", depth));
+	st = yes_state;
+	yes_state = st->u.yes.prev_yes_state;
+	PL_regmatch_state = st;
+
+	switch (st->resume_state) {
+	case resume_EVAL:
+	    if (st->u.eval.toggleutf)
+		PL_reg_flags ^= RF_utf8;
+	    ReREFCNT_dec(rex);
+	    rex = st->u.eval.prev_rex;
+	    /* XXXX This is too dramatic a measure... */
+	    PL_reg_maxiter = 0;
+	    /* Restore parens of the caller without popping the
+	     * savestack */
+	    {
+		I32 tmp = PL_savestack_ix;
+		PL_savestack_ix = st->u.eval.lastcp;
+		regcppop(rex);
+		PL_savestack_ix = tmp;
+	    }
+	    PL_reginput = locinput;
+	     /* continue at the node following the (??{...}) */
+	    next	= st->next;
+	    goto reenter;
+
+	case resume_IFMATCH:
+	    if (st->logical) {
+		st->logical = 0;
+		st->sw = st->u.ifmatch.wanted;
+	    }
+	    else if (!st->u.ifmatch.wanted)
+		sayNO;
+
+	    if (OP(st->scan) == SUSPEND)
+		locinput = PL_reginput;
+	    else {
+		locinput = PL_reginput = st->locinput;
+		nextchr = UCHARAT(locinput);
+	    }
+	    next = st->scan + ARG(st->scan);
+	    if (next == st->scan)
+		next = NULL;
+	    goto reenter;
+
+	/* XXX tmp  don't handle yes_state yet */
+	case resume_CURLYM1:
+	case resume_CURLYM2:
+	case resume_CURLYM3:
+	case resume_CURLYM4:
+	    PL_regmatch_slab =oslab;
+	    st = ost;
+	    PL_regmatch_state = st;
+	    depth = odepth;
+	    yes_state = oys;
+	    DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "XXX revering a CURLYM\n"));
+	    goto yes;
+
+	default:
+	    Perl_croak(aTHX_ "unexpected yes reume state");
+	}
+    }
+
     DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%sMatch successful!%s\n",
 			  PL_colors[4], PL_colors[5]));
 yes:
@@ -4431,7 +4519,8 @@ yes:
 
     result = 1;
     /* XXX this is duplicate(ish) code to that in the do_no section.
-     * eventually a yes should just pop the whole stack */
+     * eventually a yes should just pop the stack back to the current
+     * yes_state */
     if (depth) {
 	/* restore previous state and re-enter */
 	POP_STATE;
@@ -4441,8 +4530,6 @@ yes:
 	    goto resume_point_TRIE1;
 	case resume_TRIE2:
 	    goto resume_point_TRIE2;
-	case resume_EVAL:
-	    break;
 	case resume_CURLYX:
 	    goto resume_point_CURLYX;
 	case resume_WHILEM1:
@@ -4465,8 +4552,6 @@ yes:
 	    goto resume_point_CURLYM3;
 	case resume_CURLYM4:
 	    goto resume_point_CURLYM4;
-	case resume_IFMATCH:
-	    goto resume_point_IFMATCH;
 	case resume_PLUS1:
 	    goto resume_point_PLUS1;
 	case resume_PLUS2:
@@ -4475,6 +4560,9 @@ yes:
 	    goto resume_point_PLUS3;
 	case resume_PLUS4:
 	    goto resume_point_PLUS4;
+
+	case resume_IFMATCH:
+	case resume_EVAL:
 	default:
 	    Perl_croak(aTHX_ "regexp resume memory corruption");
 	}
@@ -4560,7 +4648,7 @@ do_no:
 		PL_reg_flags ^= RF_utf8;
 	    ReREFCNT_dec(rex);
 	    rex = st->u.eval.prev_rex;
-	    cur_eval = st->u.eval.prev_eval;
+	    yes_state = st->u.yes.prev_yes_state;
 
 	    /* XXXX This is too dramatic a measure... */
 	    PL_reg_maxiter = 0;
@@ -4593,7 +4681,22 @@ do_no:
 	case resume_CURLYM4:
 	    goto resume_point_CURLYM4;
 	case resume_IFMATCH:
-	    goto resume_point_IFMATCH;
+	    yes_state = st->u.yes.prev_yes_state;
+	    if (st->logical) {
+		st->logical = 0;
+		st->sw = !st->u.ifmatch.wanted;
+	    }
+	    else if (st->u.ifmatch.wanted)
+		sayNO;
+
+	    assert(OP(scan) != SUSPEND); /* XXX DAPM tmp */
+	    locinput = PL_reginput = st->locinput;
+	    nextchr = UCHARAT(locinput);
+	    next = scan + ARG(scan);
+	    if (next == scan)
+		next = NULL;
+	    goto reenter;
+
 	case resume_PLUS1:
 	    goto resume_point_PLUS1;
 	case resume_PLUS2: