Jumbo regexp patch applied (with minor fix-up tweaks):

	Subject: Version 7 of Jumbo RE patch available

p4raw-id: //depot/perl@267

1 files changed, 1374 insertions, 475 deletions

diff --git a/regcomp.c b/regcomp.c
index c8118f2553..6489b78392 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -56,12 +56,28 @@
 #include "EXTERN.h"
 #include "perl.h"
 #include "INTERN.h"
+
+#define REG_COMP_C
 #include "regcomp.h"
 
 #ifdef USE_THREADS
 #undef op
 #endif /* USE_THREADS */
 
+static regnode regdummy;
+static char *  regparse;       /* Input-scan pointer. */
+static char *  regxend;        /* End of input for compile */
+static regnode *       regcode;        /* Code-emit pointer; &regdummy = don't. */
+static I32             regnaughty;     /* How bad is this pattern? */
+static I32             regsawback;     /* Did we see \1, ...? */
+
+/* This guys appear both in regcomp.c and regexec.c, but there is no
+   other reason to have them global. */
+static char *  regprecomp;     /* uncompiled string. */
+static I32		regnpar;	/* () count. */
+static I32		regsize;	/* Code size. */
+static U16		regflags;	/* are we folding, multilining? */
+
 #ifdef MSDOS
 # if defined(BUGGY_MSC6)
  /* MSC 6.00A breaks on op/regexp.t test 85 unless we turn this off */
@@ -100,22 +116,580 @@
  * Forward declarations for pregcomp()'s friends.
  */
 
-static char *reg _((I32, I32 *));
-static char *reganode _((char, unsigned short));
-static char *regatom _((I32 *));
-static char *regbranch _((I32 *));
-static void regc _((char));
-static char *regclass _((void));
+static regnode *reg _((I32, I32 *));
+static regnode *reganode _((U8, U32));
+static regnode *regatom _((I32 *));
+static regnode *regbranch _((I32 *, I32));
+static void regc _((U8, char *));
+static regnode *regclass _((void));
 STATIC I32 regcurly _((char *));
-static char *regnode _((char));
-static char *regpiece _((I32 *));
-static void reginsert _((char, char *));
-static void regoptail _((char *, char *));
+static regnode *reg_node _((U8));
+static regnode *regpiece _((I32 *));
+static void reginsert _((U8, regnode *));
+static void regoptail _((regnode *, regnode *));
 static void regset _((char *, I32));
-static void regtail _((char *, char *));
+static void regtail _((regnode *, regnode *));
 static char* regwhite _((char *, char *));
 static char* nextchar _((void));
 
+static U32 regseen;
+static I32 seen_zerolen;
+static regexp *rx;
+static I32 extralen;
+
+#ifdef DEBUGGING
+static int colorset;
+char *colors[4];
+#endif 
+
+/* Length of a variant. */
+
+typedef struct {
+    I32 len_min;
+    I32 len_delta;
+    I32 pos_min;
+    I32 pos_delta;
+    SV *last_found;
+    I32 last_end;			/* min value, <0 unless valid. */
+    I32 last_start_min;
+    I32 last_start_max;
+    SV **longest;			/* Either &l_fixed, or &l_float. */
+    SV *longest_fixed;
+    I32 offset_fixed;
+    SV *longest_float;
+    I32 offset_float_min;
+    I32 offset_float_max;
+    I32 flags;
+} scan_data_t;
+
+static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+
+#define SF_BEFORE_EOL		(SF_BEFORE_SEOL|SF_BEFORE_MEOL)
+#define SF_BEFORE_SEOL		0x1
+#define SF_BEFORE_MEOL		0x2
+#define SF_FIX_BEFORE_EOL	(SF_FIX_BEFORE_SEOL|SF_FIX_BEFORE_MEOL)
+#define SF_FL_BEFORE_EOL	(SF_FL_BEFORE_SEOL|SF_FL_BEFORE_MEOL)
+
+#define SF_FIX_SHIFT_EOL	(+2)
+#define SF_FL_SHIFT_EOL		(+4)
+
+#define SF_FIX_BEFORE_SEOL	(SF_BEFORE_SEOL << SF_FIX_SHIFT_EOL)
+#define SF_FIX_BEFORE_MEOL	(SF_BEFORE_MEOL << SF_FIX_SHIFT_EOL)
+
+#define SF_FL_BEFORE_SEOL	(SF_BEFORE_SEOL << SF_FL_SHIFT_EOL)
+#define SF_FL_BEFORE_MEOL	(SF_BEFORE_MEOL << SF_FL_SHIFT_EOL) /* 0x20 */
+#define SF_IS_INF		0x40
+#define SF_HAS_PAR		0x80
+#define SF_IN_PAR		0x100
+#define SF_HAS_EVAL		0x200
+
+static void
+scan_commit(scan_data_t *data)
+{
+    STRLEN l = SvCUR(data->last_found);
+    STRLEN old_l = SvCUR(*data->longest);
+    
+    if ((l >= old_l) && ((l > old_l) || (data->flags & SF_BEFORE_EOL))) {
+	sv_setsv(*data->longest, data->last_found);
+	if (*data->longest == data->longest_fixed) {
+	    data->offset_fixed = l ? data->last_start_min : data->pos_min;
+	    if (data->flags & SF_BEFORE_EOL)
+		data->flags 
+		    |= ((data->flags & SF_BEFORE_EOL) << SF_FIX_SHIFT_EOL);
+	    else
+		data->flags &= ~SF_FIX_BEFORE_EOL;
+	} else {
+	    data->offset_float_min = l ? data->last_start_min : data->pos_min;
+	    data->offset_float_max = (l 
+				      ? data->last_start_max 
+				      : data->pos_min + data->pos_delta);
+	    if (data->flags & SF_BEFORE_EOL)
+		data->flags 
+		    |= ((data->flags & SF_BEFORE_EOL) << SF_FL_SHIFT_EOL);
+	    else
+		data->flags &= ~SF_FL_BEFORE_EOL;
+	}
+    }
+    SvCUR_set(data->last_found, 0);
+    data->last_end = -1;
+    data->flags &= ~SF_BEFORE_EOL;
+}
+
+#define SCF_DO_SUBSTR 1
+
+/* Stops at toplevel WHILEM as well as at `last'. At end *scanp is set
+   to the position after last scanned or to NULL. */
+
+static I32
+study_chunk(regnode **scanp, I32 *deltap, regnode *last, scan_data_t *data, U32 flags)
+			/* scanp: Start here (read-write). */
+			/* deltap: Write maxlen-minlen here. */
+			/* last: Stop before this one. */
+{
+    I32 min = 0, pars = 0, code;
+    regnode *scan = *scanp, *next;
+    I32 delta = 0;
+    int is_inf = (flags & SCF_DO_SUBSTR) && (data->flags & SF_IS_INF);
+    I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
+    scan_data_t data_fake;
+    
+    while (scan && OP(scan) != END && scan < last) {
+	/* Peephole optimizer: */
+
+	if (regkind[(U8)OP(scan)] == EXACT) {
+	    regnode *n = regnext(scan);
+	    U32 stringok = 1;
+#ifdef DEBUGGING
+	    regnode *stop = scan;
+#endif 
+
+	    next = scan + (*OPERAND(scan) + 2 - 1)/sizeof(regnode) + 2;
+	    /* Skip NOTHING, merge EXACT*. */
+	    while (n &&
+		   ( regkind[(U8)OP(n)] == NOTHING || 
+		     (stringok && (OP(n) == OP(scan))))
+		   && NEXT_OFF(n)
+		   && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX) {
+		if (OP(n) == TAIL || n > next)
+		    stringok = 0;
+		if (regkind[(U8)OP(n)] == NOTHING) {
+		    NEXT_OFF(scan) += NEXT_OFF(n);
+		    next = n + NODE_STEP_REGNODE;
+#ifdef DEBUGGING
+		    if (stringok)
+			stop = n;
+#endif 
+		    n = regnext(n);
+		} else {
+		    int oldl = *OPERAND(scan);
+		    regnode *nnext = regnext(n);
+		    
+		    if (oldl + *OPERAND(n) > U8_MAX) 
+			break;
+		    NEXT_OFF(scan) += NEXT_OFF(n);
+		    *OPERAND(scan) += *OPERAND(n);
+		    next = n + (*OPERAND(n) + 2 - 1)/sizeof(regnode) + 2;
+		    /* Now we can overwrite *n : */
+		    Move(OPERAND(n) + 1, OPERAND(scan) + oldl + 1,
+			 *OPERAND(n) + 1, char);
+#ifdef DEBUGGING
+		    if (stringok)
+			stop = next - 1;
+#endif 
+		    n = nnext;
+		}
+	    }
+#ifdef DEBUGGING
+	    /* Allow dumping */
+	    n = scan + (*OPERAND(scan) + 2 - 1)/sizeof(regnode) + 2;
+	    while (n <= stop) {
+		if (regkind[(U8)OP(n)] != NOTHING || OP(n) == NOTHING) {
+		    OP(n) = OPTIMIZED;
+		    NEXT_OFF(n) = 0;
+		}
+		n++;
+	    }
+#endif 
+
+	}
+	if (OP(scan) != CURLYX) {
+	    int max = (reg_off_by_arg[OP(scan)] ? I32_MAX : U16_MAX);
+	    int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
+	    int noff;
+	    regnode *n = scan;
+	    
+	    /* Skip NOTHING and LONGJMP. */
+	    while ((n = regnext(n))
+		   && ((regkind[(U8)OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
+		       || ((OP(n) == LONGJMP) && (noff = ARG(n))))
+		   && off + noff < max)
+		off += noff;
+	    if (reg_off_by_arg[OP(scan)])
+		ARG(scan) = off;
+	    else 
+		NEXT_OFF(scan) = off;
+	}
+	if (OP(scan) == BRANCH || OP(scan) == BRANCHJ 
+		   || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
+	    next = regnext(scan);
+	    code = OP(scan);
+	    
+	    if (OP(next) == code || code == IFTHEN || code == SUSPEND) { 
+		I32 max1 = 0, min1 = I32_MAX, num = 0;
+		
+		if (flags & SCF_DO_SUBSTR)
+		    scan_commit(data);
+		while (OP(scan) == code) {
+		    I32 deltanext, minnext;
+
+		    num++;
+		    data_fake.flags = 0;
+		    next = regnext(scan);
+		    scan = NEXTOPER(scan);
+		    if (code != BRANCH)
+			scan = NEXTOPER(scan);
+		    /* We suppose the run is continuous, last=next...*/
+		    minnext = study_chunk(&scan, &deltanext, next,
+					  &data_fake, 0);
+		    if (min1 > minnext) 
+			min1 = minnext;
+		    if (max1 < minnext + deltanext)
+			max1 = minnext + deltanext;
+		    if (deltanext == I32_MAX)
+			is_inf = 1;
+		    scan = next;
+		    if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
+			pars++;
+		    if (data_fake.flags & SF_HAS_EVAL)
+			data->flags |= SF_HAS_EVAL;
+		    if (code == SUSPEND) 
+			break;
+		}
+		if (code == IFTHEN && num < 2) /* Empty ELSE branch */
+		    min1 = 0;
+		if (flags & SCF_DO_SUBSTR) {
+		    data->pos_min += min1;
+		    data->pos_delta += max1 - min1;
+		    if (max1 != min1 || is_inf)
+			data->longest = &(data->longest_float);
+		}
+		min += min1;
+		delta += max1 - min1;
+	    } else if (code == BRANCHJ)	/* single branch is optimized. */
+		scan = NEXTOPER(NEXTOPER(scan));
+	    else			/* single branch is optimized. */
+		scan = NEXTOPER(scan);
+	    continue;
+	} else if (OP(scan) == EXACT) {
+	    min += *OPERAND(scan);
+	    if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
+		I32 l = *OPERAND(scan);
+
+		/* The code below prefers earlier match for fixed
+		   offset, later match for variable offset.  */
+		if (data->last_end == -1) { /* Update the start info. */
+		    data->last_start_min = data->pos_min;
+ 		    data->last_start_max = is_inf
+ 			? I32_MAX : data->pos_min + data->pos_delta; 
+		}
+		sv_catpvn(data->last_found, OPERAND(scan)+1, l);
+		data->last_end = data->pos_min + l;
+		data->pos_min += l; /* As in the first entry. */
+		data->flags &= ~SF_BEFORE_EOL;
+	    }
+	} else if (regkind[(U8)OP(scan)] == EXACT) {
+	    if (flags & SCF_DO_SUBSTR) 
+		scan_commit(data);
+	    min += *OPERAND(scan);
+	    if (data && (flags & SCF_DO_SUBSTR))
+		data->pos_min += *OPERAND(scan);
+	} else if (strchr(varies,OP(scan))) {
+	    I32 mincount, maxcount, minnext, deltanext, pos_before, fl;
+	    regnode *oscan = scan;
+	    
+	    switch (regkind[(U8)OP(scan)]) {
+	    case WHILEM:
+		scan = NEXTOPER(scan);
+		goto finish;
+	    case PLUS:
+		if (flags & SCF_DO_SUBSTR) {
+		    next = NEXTOPER(scan);
+		    if (OP(next) == EXACT) {
+			mincount = 1; 
+			maxcount = REG_INFTY; 
+			next = regnext(scan);
+			scan = NEXTOPER(scan);
+			goto do_curly;
+		    }
+		}
+		if (flags & SCF_DO_SUBSTR)
+		    data->pos_min++;
+		min++;
+		/* Fall through. */
+	    case STAR:
+		is_inf = 1; 
+		scan = regnext(scan);
+		if (flags & SCF_DO_SUBSTR) {
+		    scan_commit(data);
+		    data->longest = &(data->longest_float);
+		}
+		goto optimize_curly_tail;
+	    case CURLY:
+		mincount = ARG1(scan); 
+		maxcount = ARG2(scan);
+		next = regnext(scan);
+		scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
+	      do_curly:
+		if (flags & SCF_DO_SUBSTR) {
+		    if (mincount == 0) scan_commit(data);
+		    pos_before = data->pos_min;
+		}
+		if (data) {
+		    fl = data->flags;
+		    data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
+		    if (is_inf)
+			data->flags |= SF_IS_INF;
+		}
+		/* This will finish on WHILEM, setting scan, or on NULL: */
+		minnext = study_chunk(&scan, &deltanext, last, data, 
+				      mincount == 0 
+					? (flags & ~SCF_DO_SUBSTR) : flags);
+		if (!scan) 		/* It was not CURLYX, but CURLY. */
+		    scan = next;
+		if (dowarn && (minnext + deltanext == 0) 
+		    && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))) 
+		    warn("Strange *+?{} on zero-length expression");
+		min += minnext * mincount;
+		is_inf |= (maxcount == REG_INFTY && (minnext + deltanext) > 0
+			   || deltanext == I32_MAX);
+		delta += (minnext + deltanext) * maxcount - minnext * mincount;
+
+		/* Try powerful optimization CURLYX => CURLYN. */
+#ifdef REGALIGN_STRUCT
+		if (  OP(oscan) == CURLYX && data 
+		      && data->flags & SF_IN_PAR
+		      && !(data->flags & SF_HAS_EVAL)
+		      && !deltanext && minnext == 1 ) {
+		    /* Try to optimize to CURLYN.  */
+		    regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
+		    regnode *nxt1 = nxt, *nxt2;
+
+		    /* Skip open. */
+		    nxt = regnext(nxt);
+		    if (!strchr(simple,OP(nxt))
+			&& !(regkind[(U8)OP(nxt)] == EXACT
+			     && *OPERAND(nxt) == 1)) 
+			goto nogo;
+		    nxt2 = nxt;
+		    nxt = regnext(nxt);
+		    if (OP(nxt) != CLOSE) 
+			goto nogo;
+		    /* Now we know that nxt2 is the only contents: */
+		    oscan->flags = ARG(nxt);
+		    OP(oscan) = CURLYN;
+		    OP(nxt1) = NOTHING;	/* was OPEN. */
+#ifdef DEBUGGING
+		    OP(nxt1 + 1) = OPTIMIZED; /* was count. */
+		    NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
+		    NEXT_OFF(nxt2) = 0;	/* just for consistancy with CURLY. */
+		    OP(nxt) = OPTIMIZED;	/* was CLOSE. */
+		    OP(nxt + 1) = OPTIMIZED; /* was count. */
+		    NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
+#endif 
+		}
+#endif 
+	      nogo:
+
+		/* Try optimization CURLYX => CURLYM. */
+		if (  OP(oscan) == CURLYX && data 
+#ifdef REGALIGN_STRUCT
+		      && !(data->flags & SF_HAS_PAR)
+#else
+		      && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
+#endif 
+		      && !(data->flags & SF_HAS_EVAL)
+		      && !deltanext  ) {
+		    /* XXXX How to optimize if data == 0? */
+		    /* Optimize to a simpler form.  */
+		    regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
+		    regnode *nxt2;
+
+		    OP(oscan) = CURLYM;
+		    while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
+			    && (OP(nxt2) != WHILEM)) 
+			nxt = nxt2;
+		    OP(nxt2)  = SUCCEED; /* Whas WHILEM */
+#ifdef REGALIGN_STRUCT
+		    /* Need to optimize away parenths. */
+		    if (data->flags & SF_IN_PAR) {
+			/* Set the parenth number.  */
+			regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
+
+			if (OP(nxt) != CLOSE) 
+			    FAIL("panic opt close");
+			oscan->flags = ARG(nxt);
+			OP(nxt1) = OPTIMIZED;	/* was OPEN. */
+			OP(nxt) = OPTIMIZED;	/* was CLOSE. */
+#ifdef DEBUGGING
+			OP(nxt1 + 1) = OPTIMIZED; /* was count. */
+			OP(nxt + 1) = OPTIMIZED; /* was count. */
+			NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
+			NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
+#endif 
+#if 0
+			while ( nxt1 && (OP(nxt1) != WHILEM)) {
+			    regnode *nnxt = regnext(nxt1);
+			    
+			    if (nnxt == nxt) {
+				if (reg_off_by_arg[OP(nxt1)])
+				    ARG_SET(nxt1, nxt2 - nxt1);
+				else if (nxt2 - nxt1 < U16_MAX)
+				    NEXT_OFF(nxt1) = nxt2 - nxt1;
+				else
+				    OP(nxt) = NOTHING;	/* Cannot beautify */
+			    }
+			    nxt1 = nnxt;
+			}
+#endif
+			/* Optimize again: */
+			study_chunk(&nxt1, &deltanext, nxt, NULL, 0);
+		    } else
+			oscan->flags = 0;
+#endif 
+		}
+		if (data && fl & (SF_HAS_PAR|SF_IN_PAR)) 
+		    pars++;
+		if (flags & SCF_DO_SUBSTR) {
+		    SV *last_str = Nullsv;
+		    int counted = mincount != 0;
+
+		    if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
+			I32 b = pos_before >= data->last_start_min 
+			    ? pos_before : data->last_start_min;
+			STRLEN l;
+			char *s = SvPV(data->last_found, l);
+			
+			l -= b - data->last_start_min;
+			/* Get the added string: */
+			last_str = newSVpv(s  +  b - data->last_start_min, l);
+			if (deltanext == 0 && pos_before == b) {
+			    /* What was added is a constant string */
+			    if (mincount > 1) {
+				SvGROW(last_str, (mincount * l) + 1);
+				repeatcpy(SvPVX(last_str) + l, 
+					  SvPVX(last_str), l, mincount - 1);
+				SvCUR(last_str) *= mincount;
+				/* Add additional parts. */
+				SvCUR_set(data->last_found, 
+					  SvCUR(data->last_found) - l);
+				sv_catsv(data->last_found, last_str);
+				data->last_end += l * (mincount - 1);
+			    }
+			}
+		    }
+		    /* It is counted once already... */
+		    data->pos_min += minnext * (mincount - counted);
+		    data->pos_delta += - counted * deltanext +
+			(minnext + deltanext) * maxcount - minnext * mincount;
+		    if (mincount != maxcount) {
+			scan_commit(data);
+			if (mincount && last_str) {
+			    sv_setsv(data->last_found, last_str);
+			    data->last_end = data->pos_min;
+			    data->last_start_min = 
+				data->pos_min - SvCUR(last_str);
+			    data->last_start_max = is_inf 
+				? I32_MAX 
+				: data->pos_min + data->pos_delta
+				- SvCUR(last_str);
+			}
+			data->longest = &(data->longest_float);
+		    }
+		}
+		if (fl & SF_HAS_EVAL)
+		    data->flags |= SF_HAS_EVAL;
+	      optimize_curly_tail:
+#ifdef REGALIGN
+		if (OP(oscan) != CURLYX) {
+		    while (regkind[(U8)OP(next = regnext(oscan))] == NOTHING
+			   && NEXT_OFF(next))
+			NEXT_OFF(oscan) += NEXT_OFF(next);
+		}
+#endif
+		continue;
+	    default:			/* REF only? */
+		if (flags & SCF_DO_SUBSTR) {
+		    scan_commit(data);
+		    data->longest = &(data->longest_float);
+		}
+		is_inf = 1;
+		break;
+	    }
+	} else if (strchr(simple,OP(scan))) {
+	    if (flags & SCF_DO_SUBSTR) {
+		scan_commit(data);
+		data->pos_min++;
+	    }
+	    min++;
+	} else if (regkind[(U8)OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
+	    data->flags |= (OP(scan) == MEOL
+			    ? SF_BEFORE_MEOL
+			    : SF_BEFORE_SEOL);
+	} else if (regkind[(U8)OP(scan)] == BRANCHJ
+		   && (scan->flags || data)
+		   && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
+	    I32 deltanext, minnext;
+	    regnode *nscan;
+
+	    data_fake.flags = 0;
+	    next = regnext(scan);
+	    nscan = NEXTOPER(NEXTOPER(scan));
+	    minnext = study_chunk(&nscan, &deltanext, last, &data_fake, 0);
+	    if (scan->flags) {
+		if (deltanext) {
+		    FAIL("variable length lookbehind not implemented");
+		} else if (minnext > U8_MAX) {
+		    FAIL2("lookbehind longer than %d not implemented", U8_MAX);
+		}
+		scan->flags = minnext;
+	    }
+	    if (data && data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
+		pars++;
+	    if (data_fake.flags & SF_HAS_EVAL)
+		data->flags |= SF_HAS_EVAL;
+	} else if (OP(scan) == OPEN) {
+	    pars++;
+	} else if (OP(scan) == CLOSE && ARG(scan) == is_par) {
+#ifdef REGALIGN_STRUCT
+	    next = regnext(scan);
+
+	    if ( next && (OP(next) != WHILEM) && next < last)
+#endif 
+		is_par = 0;		/* Disable optimization */
+	} else if (OP(scan) == EVAL) {
+		if (data)
+		    data->flags |= SF_HAS_EVAL;
+	}
+	/* Else: zero-length, ignore. */
+	scan = regnext(scan);
+    }
+
+  finish:
+    *scanp = scan;
+    *deltap = is_inf ? I32_MAX : delta;
+    if (flags & SCF_DO_SUBSTR && is_inf) 
+	data->pos_delta = I32_MAX - data->pos_min;
+    if (is_par > U8_MAX)
+	is_par = 0;
+    if (is_par && pars==1 && data) {
+	data->flags |= SF_IN_PAR;
+	data->flags &= ~SF_HAS_PAR;
+    } else if (pars && data) {
+	data->flags |= SF_HAS_PAR;
+	data->flags &= ~SF_IN_PAR;
+    }
+    return min;
+}
+
+static I32
+add_data(I32 n, char *s)
+{
+    if (rx->data) {
+	Renewc(rx->data, 
+	       sizeof(*rx->data) + sizeof(void*) * (rx->data->count + n - 1), 
+	       char, struct reg_data);
+	Renew(rx->data->what, rx->data->count + n, U8);
+	rx->data->count += n;
+    } else {
+	Newc(1207, rx->data, sizeof(*rx->data) + sizeof(void*) * (n - 1),
+	     char, struct reg_data);
+	New(1208, rx->data->what, n, U8);
+	rx->data->count = n;
+    }
+    Copy(s, rx->data->what + rx->data->count - n, n, U8);
+    return rx->data->count - n;
+}
+
 /*
  - pregcomp - compile a regular expression into internal code
  *
@@ -135,33 +709,29 @@ regexp *
 pregcomp(char *exp, char *xend, PMOP *pm)
 {
     register regexp *r;
-    register char *scan;
-    register SV *longish;
-    SV *longest;
-    register I32 len;
-    register char *first;
+    regnode *scan;
+    SV **longest;
+    SV *longest_fixed;
+    SV *longest_float;
+    regnode *first;
     I32 flags;
-    I32 backish;
-    I32 backest;
-    I32 curback;
     I32 minlen = 0;
     I32 sawplus = 0;
     I32 sawopen = 0;
-#define MAX_REPEAT_DEPTH 12
-    struct {
-	char *opcode;
-	I32 count;
-    } repeat_stack[MAX_REPEAT_DEPTH];
-    I32 repeat_depth = 0;
-    I32 repeat_count = 1;	/* We start unmultiplied. */
 
     if (exp == NULL)
-	croak("NULL regexp argument");
+	FAIL("NULL regexp argument");
 
     regprecomp = savepvn(exp, xend - exp);
+    DEBUG_r(PerlIO_printf(Perl_debug_log, "compiling RE `%*s'\n",
+			  xend - exp, regprecomp));
     regflags = pm->op_pmflags;
     regsawback = 0;
 
+    regseen = 0;
+    seen_zerolen = *exp == '^' ? -1 : 0;
+    extralen = 0;
+
     /* First pass: determine size, legality. */
     regparse = exp;
     regxend = xend;
@@ -169,24 +739,61 @@ pregcomp(char *exp, char *xend, PMOP *pm)
     regnpar = 1;
     regsize = 0L;
     regcode = &regdummy;
-    regc((char)MAGIC);
+    regc((U8)MAGIC, (char*)regcode);
     if (reg(0, &flags) == NULL) {
 	Safefree(regprecomp);
 	regprecomp = Nullch;
 	return(NULL);
     }
+    DEBUG_r(PerlIO_printf(Perl_debug_log, "size %d ", regsize));
+
+    DEBUG_r(
+	if (!colorset) {
+	    int i = 0;
+	    char *s = getenv("TERMCAP_COLORS");
+	    
+	    colorset = 1;
+	    if (s) {
+		colors[0] = s = savepv(s);
+		while (++i < 4) {
+		    s = strchr(s, '\t');
+		    if (!s) 
+			FAIL("Not enough TABs in TERMCAP_COLORS");
+		    *s = '\0';
+		    colors[i] = ++s;
+		}
+	    } else {
+		while (i < 4) 
+		    colors[i++] = "";
+	    }
+	    /* Reset colors: */
+	    PerlIO_printf(Perl_debug_log, "%s%s%s%s", 
+			  colors[0],colors[1],colors[2],colors[3]);
+	}
+	);
 
-    /* Small enough for pointer-storage convention? */
-    if (regsize >= 32767L)		/* Probably could be 65535L. */
+    /* Small enough for pointer-storage convention?
+       If extralen==0, this means that we will not need long jumps. */
+#ifndef REGALIGN_STRUCT
+    if (regsize >= 0x10000L && extralen)
 	FAIL("regexp too big");
+#else
+    if (regsize >= 0x10000L && extralen)
+        regsize += extralen;
+    else
+	extralen = 0;
+#endif 
 
     /* Allocate space and initialize. */
-    Newc(1001, r, sizeof(regexp) + (unsigned)regsize, char, regexp);
+    Newc(1001, r, sizeof(regexp) + (unsigned)regsize * sizeof(regnode),
+	 char, regexp);
     if (r == NULL)
 	FAIL("regexp out of space");
+    r->refcnt = 1;
     r->prelen = xend - exp;
     r->precomp = regprecomp;
     r->subbeg = r->subbase = NULL;
+    rx = r;
 
     /* Second pass: emit code. */
     regparse = exp;
@@ -194,23 +801,24 @@ pregcomp(char *exp, char *xend, PMOP *pm)
     regnaughty = 0;
     regnpar = 1;
     regcode = r->program;
-    regc((char)MAGIC);
+    regc((U8)MAGIC, (char*) regcode++);
+    r->data = 0;
     if (reg(0, &flags) == NULL)
 	return(NULL);
 
     /* Dig out information for optimizations. */
     pm->op_pmflags = regflags;
-    r->regstart = Nullsv;	/* Worst-case defaults. */
     r->reganch = 0;
-    r->regmust = Nullsv;
-    r->regback = -1;
-    r->regstclass = Nullch;
+    r->regstclass = NULL;
     r->naughty = regnaughty >= 10;	/* Probably an expensive pattern. */
-    scan = r->program+1;			/* First BRANCH. */
-    if (OP(regnext(scan)) == END) {/* Only one top-level choice. */
-	scan = NEXTOPER(scan);
+    scan = r->program + 1;		/* First BRANCH. */
+    if (OP(scan) != BRANCH) {	/* Only one top-level choice. */
+	scan_data_t data;
+	I32 fake;
 
+	StructCopy(&zero_scan_data, &data, scan_data_t);
 	first = scan;
+	/* Skip introductions and multiplicators >= 1. */
 	while ((OP(first) == OPEN && (sawopen = 1)) ||
 	    (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
 	    (OP(first) == PLUS) ||
@@ -225,19 +833,14 @@ pregcomp(char *exp, char *xend, PMOP *pm)
 
 	/* Starting-point info. */
       again:
-	if (OP(first) == EXACT) {
-	    r->regstart = newSVpv(OPERAND(first)+1,*OPERAND(first));
-	    if (SvCUR(r->regstart) > !sawstudy)
-		fbm_compile(r->regstart);
-	    (void)SvUPGRADE(r->regstart, SVt_PVBM);
-	}
+	if (OP(first) == EXACT);	/* Empty, get anchored substr later. */
 	else if (strchr(simple+2,OP(first)))
 	    r->regstclass = first;
 	else if (regkind[(U8)OP(first)] == BOUND ||
 		 regkind[(U8)OP(first)] == NBOUND)
 	    r->regstclass = first;
 	else if (regkind[(U8)OP(first)] == BOL) {
-	    r->reganch |= ROPT_ANCH_BOL;
+	    r->reganch |= (OP(first) == MBOL ? ROPT_ANCH_MBOL: ROPT_ANCH_BOL);
 	    first = NEXTOPER(first);
 	    goto again;
 	}
@@ -258,8 +861,9 @@ pregcomp(char *exp, char *xend, PMOP *pm)
 	if (sawplus && (!sawopen || !regsawback))
 	    r->reganch |= ROPT_SKIP;	/* x+ must match 1st of run */
 
-	DEBUG_r(PerlIO_printf(Perl_debug_log, "first %d next %d offset %ld\n",
-	   OP(first), OP(NEXTOPER(first)), (long)(first - scan)));
+	/* Scan is after the zeroth branch, first is atomic matcher. */
+	DEBUG_r(PerlIO_printf(Perl_debug_log, "first at %d\n", 
+			      first - scan + 1));
 	/*
 	* If there's something expensive in the r.e., find the
 	* longest literal string that must appear and make it the
@@ -268,155 +872,94 @@ pregcomp(char *exp, char *xend, PMOP *pm)
 	* and avoiding duplication strengthens checking.  Not a
 	* strong reason, but sufficient in the absence of others.
 	* [Now we resolve ties in favor of the earlier string if
-	* it happens that curback has been invalidated, since the
+	* it happens that c_offset_min has been invalidated, since the
 	* earlier string may buy us something the later one won't.]
 	*/
-	longish = newSVpv("",0);
-	longest = newSVpv("",0);
-	len = 0;
 	minlen = 0;
-	curback = 0;
-	backish = 0;
-	backest = 0;
-	while (OP(scan) != END) {
-	    if (OP(scan) == BRANCH) {
-		if (OP(regnext(scan)) == BRANCH) {
-		    curback = -30000;
-		    while (OP(scan) == BRANCH)
-			scan = regnext(scan);
-		}
-		else	/* single branch is ok */
-		    scan = NEXTOPER(scan);
-		continue;
-	    }
-	    if (OP(scan) == UNLESSM) {
-		curback = -30000;
-		scan = regnext(scan);
-		continue;
-	    }
-	    if (OP(scan) == EXACT) {
-		char *t;
-
-		first = scan;
-		while ((t = regnext(scan)) && OP(t) == CLOSE)
-		    scan = t;
-		minlen += *OPERAND(first) * repeat_count;
-		if (curback - backish == len) {
-		    sv_catpvn(longish, OPERAND(first)+1,
-			*OPERAND(first));
-		    len += *OPERAND(first);
-		    curback += *OPERAND(first);
-		    first = regnext(scan);
-		}
-		else if (*OPERAND(first) >= len + (curback >= 0)) {
-		    len = *OPERAND(first);
-		    sv_setpvn(longish, OPERAND(first)+1,len);
-		    backish = curback;
-		    curback += len;
-		    first = regnext(scan);
-		}
-		else
-		    curback += *OPERAND(first);
-	    }
-	    else if (strchr(varies,OP(scan))) {
-		int tcount;
-		char *next;
-
-		if (repeat_depth < MAX_REPEAT_DEPTH
-		    && ((OP(scan) == PLUS
-			 && (tcount = 1)
-			 && (next = NEXTOPER(scan)))
-			|| (regkind[(U8)OP(scan)] == CURLY
-			    && (tcount = ARG1(scan))
-			    && (next = NEXTOPER(scan)+4))))
-		{
-		    /* We treat (abc)+ as (abc)(abc)*. */
-
-		    /* Mark the place to return back. */
-		    repeat_stack[repeat_depth].opcode = regnext(scan);
-		    repeat_stack[repeat_depth].count = repeat_count;
-		    repeat_depth++;
-		    repeat_count *= tcount;
-
-		    /* Go deeper: */
-		    scan = next;
-		    continue;
-		}
-		else {
-		    curback = -30000;
-		    len = 0;
-		    if (SvCUR(longish) > SvCUR(longest)) {
-			sv_setsv(longest,longish);
-			backest = backish;
-		    }
-		    sv_setpvn(longish,"",0);
-		}
-	    }
-	    else if (strchr(simple,OP(scan))) {
-		curback++;
-		minlen += repeat_count;
-		len = 0;
-		if (SvCUR(longish) > SvCUR(longest)) {
-		    sv_setsv(longest,longish);
-		    backest = backish;
-		}
-		sv_setpvn(longish,"",0);
-	    }
-	    scan = regnext(scan);
-	    if (!scan) {		/* Go up PLUS or CURLY. */
-		if (!repeat_depth--)
-		    croak("panic: re scan");
-		scan = repeat_stack[repeat_depth].opcode;
-		repeat_count = repeat_stack[repeat_depth].count;
-		/* Need to submit the longest string found: */
-		curback = -30000;
-		len = 0;
-		if (SvCUR(longish) > SvCUR(longest)) {
-		    sv_setsv(longest,longish);
-		    backest = backish;
-		}
-		sv_setpvn(longish,"",0);
-	    }
-	}
 
-	/* Prefer earlier on tie, unless we can tail match latter */
-
-	if (SvCUR(longish) + (first && regkind[(U8)OP(first)] == EOL)
-		> SvCUR(longest))
-	{
-	    sv_setsv(longest,longish);
-	    backest = backish;
+	data.longest_fixed = newSVpv("",0);
+	data.longest_float = newSVpv("",0);
+	data.last_found = newSVpv("",0);
+	data.longest = &(data.longest_fixed);
+	first = scan;
+	
+	minlen = study_chunk(&first, &fake, scan + regsize, /* Up to end */
+			     &data, SCF_DO_SUBSTR);
+	if ( regnpar == 1 && data.longest == &(data.longest_fixed)
+	     && data.last_start_min == 0 && data.last_end > 0 
+	     && !seen_zerolen
+	     && (!(regseen & REG_SEEN_GPOS) || (r->reganch & ROPT_ANCH_GPOS)))
+	    r->reganch |= ROPT_CHECK_ALL;
+	scan_commit(&data);
+	SvREFCNT_dec(data.last_found);
+
+	if (SvCUR(data.longest_float)
+	    || (data.flags & SF_FL_BEFORE_EOL
+		&& (!(data.flags & SF_FL_BEFORE_MEOL)
+		    || (regflags & PMf_MULTILINE)))) {
+	    if (SvCUR(data.longest_fixed) 
+		&& data.offset_fixed == data.offset_float_min)
+		goto remove;		/* Like in (a)+. */
+	    
+	    r->float_substr = data.longest_float;
+	    r->float_min_offset = data.offset_float_min;
+	    r->float_max_offset = data.offset_float_max;
+	    fbm_compile(r->float_substr);
+	    BmUSEFUL(r->float_substr) = 100;
+	    if (data.flags & SF_FL_BEFORE_EOL /* Cannot have SEOL and MULTI */
+		&& (!(data.flags & SF_FL_BEFORE_MEOL)
+		    || (regflags & PMf_MULTILINE))) 
+		SvTAIL_on(r->float_substr);
+	} else {
+	  remove:
+	    r->float_substr = Nullsv;
+	    SvREFCNT_dec(data.longest_float);
 	}
-	else
-	    sv_setpvn(longish,"",0);
-	if (SvCUR(longest)
-	    && (!r->regstart
-		|| !fbm_instr((unsigned char*) SvPVX(r->regstart),
-			      (unsigned char *) (SvPVX(r->regstart)
-						 + SvCUR(r->regstart)),
-			      longest)))
-	{
-	    r->regmust = longest;
-	    if (backest < 0)
-		backest = -1;
-	    r->regback = backest;
-	    if (SvCUR(longest) > !(sawstudy || 
-				   (first && regkind[(U8)OP(first)] == EOL)))
-		fbm_compile(r->regmust);
-	    (void)SvUPGRADE(r->regmust, SVt_PVBM);
-	    BmUSEFUL(r->regmust) = 100;
-	    if (first && regkind[(U8)OP(first)] == EOL && SvCUR(longish))
-		SvTAIL_on(r->regmust);
+
+	if (SvCUR(data.longest_fixed)
+	    || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
+		&& (!(data.flags & SF_FIX_BEFORE_MEOL)
+		    || (regflags & PMf_MULTILINE)))) {
+	    r->anchored_substr = data.longest_fixed;
+	    r->anchored_offset = data.offset_fixed;
+	    fbm_compile(r->anchored_substr);
+	    BmUSEFUL(r->anchored_substr) = 100;
+	    if (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
+		&& (!(data.flags & SF_FIX_BEFORE_MEOL)
+		    || (regflags & PMf_MULTILINE)))
+		SvTAIL_on(r->anchored_substr);
+	} else {
+	    r->anchored_substr = Nullsv;
+	    SvREFCNT_dec(data.longest_fixed);
 	}
-	else {
-	    SvREFCNT_dec(longest);
-	    longest = Nullsv;
+
+	/* A temporary algorithm prefers floated substr to fixed one to dig more info. */
+	if (SvCUR(data.longest_fixed) > SvCUR(data.longest_float)) {
+	    r->check_substr = r->anchored_substr;
+	    r->check_offset_min = r->check_offset_max = r->anchored_offset;
+	    if (r->reganch & ROPT_ANCH_SINGLE)
+		r->reganch |= ROPT_NOSCAN;
+	} else {
+	    r->check_substr = r->float_substr;
+	    r->check_offset_min = data.offset_float_min;
+	    r->check_offset_max = data.offset_float_max;
 	}
-	SvREFCNT_dec(longish);
+    } else {
+	/* Several toplevels. Best we can is to set minlen. */
+	I32 fake;
+	
+	DEBUG_r(PerlIO_printf(Perl_debug_log, "\n"));
+	scan = r->program + 1;
+	minlen = study_chunk(&scan, &fake, scan + regsize, NULL, 0);
+	r->check_substr = r->anchored_substr = r->float_substr = Nullsv;
     }
 
     r->nparens = regnpar - 1;
     r->minlen = minlen;
+    if (regseen & REG_SEEN_GPOS) 
+	r->reganch |= ROPT_GPOS_SEEN;
+    if (regseen & REG_SEEN_LOOKBEHIND)
+	r->reganch |= ROPT_LOOKBEHIND_SEEN;
     Newz(1002, r->startp, regnpar, char*);
     Newz(1002, r->endp, regnpar, char*);
     DEBUG_r(regdump(r));
@@ -432,16 +975,17 @@ pregcomp(char *exp, char *xend, PMOP *pm)
  * is a trifle forced, but the need to tie the tails of the branches to what
  * follows makes it hard to avoid.
  */
-static char *
+static regnode *
 reg(I32 paren, I32 *flagp)
-          			/* Parenthesized? */
-           
+    /* paren: Parenthesized? 0=top, 1=(, inside: changed to letter. */
 {
-    register char *ret;
-    register char *br;
-    register char *ender = 0;
+    register regnode *ret;		/* Will be the head of the group. */
+    register regnode *br;
+    register regnode *lastbr;
+    register regnode *ender = 0;
     register I32 parno = 0;
-    I32 flags;
+    I32 flags, oregflags = regflags, have_branch = 0, open = 0;
+    char c;
 
     *flagp = HASWIDTH;	/* Tentatively. */
 
@@ -450,33 +994,138 @@ reg(I32 paren, I32 *flagp)
 	if (*regparse == '?') {
 	    regparse++;
 	    paren = *regparse++;
-	    ret = NULL;
+	    ret = NULL;			/* For look-ahead/behind. */
 	    switch (paren) {
-	    case ':':
+	    case '<':
+#ifndef REGALIGN_STRUCT
+		FAIL("lookbehind non-implemented without REGALIGN_STRUCT");
+#endif 
+		regseen |= REG_SEEN_LOOKBEHIND;
+		if (*regparse == '!') 
+		    paren = ',';
+		if (*regparse != '=' && *regparse != '!') 
+		    goto unknown;
+		regparse++;
 	    case '=':
 	    case '!':
+		seen_zerolen++;
+	    case ':':
+	    case '>':
 		break;
 	    case '$':
 	    case '@':
-		croak("Sequence (?%c...) not implemented", (int)paren);
+		FAIL2("Sequence (?%c...) not implemented", (int)paren);
 		break;
 	    case '#':
 		while (*regparse && *regparse != ')')
 		    regparse++;
 		if (*regparse != ')')
-		    croak("Sequence (?#... not terminated");
+		    FAIL("Sequence (?#... not terminated");
 		nextchar();
 		*flagp = TRYAGAIN;
 		return NULL;
+	    case '{':
+	    {
+		dTHR;
+		I32 count = 1, n = 0;
+		char c;
+		char *s = regparse;
+		SV *sv;
+		OP_4tree *sop, *rop;
+
+		seen_zerolen++;
+		while (count && (c = *regparse)) {
+		    if (c == '\\' && regparse[1])
+			regparse++;
+		    else if (c == '{') 
+			count++;
+		    else if (c == '}') 
+			count--;
+		    regparse++;
+		}
+		if (*regparse != ')')
+		    FAIL("Sequence (?{...}) not terminated or not {}-balanced");
+		if (!SIZE_ONLY) {
+		    AV *av;
+		    
+		    if (regparse - 1 - s) 
+			sv = newSVpv(s, regparse - 1 - s);
+		    else
+			sv = newSVpv("", 0);
+
+		    rop = sv_compile_2op(sv, &sop, "re", &av);
+
+		    n = add_data(3, "nso");
+		    rx->data->data[n] = (void*)rop;
+		    rx->data->data[n+1] = (void*)av;
+		    rx->data->data[n+2] = (void*)sop;
+		    SvREFCNT_dec(sv);
+		}
+		
+		nextchar();
+		if (tainted)
+		    FAIL("Eval-group in insecure regular expression");
+		return reganode(EVAL, n);
+	    }
+	    case '(':
+	    {
+		if (regparse[0] == '?') {
+		    if (regparse[1] == '=' || regparse[1] == '!' 
+			|| regparse[1] == '<' 
+			|| regparse[1] == '{') { /* Lookahead or eval. */
+			I32 flag;
+			
+			ret = reg_node(LOGICAL);
+			regtail(ret, reg(1, &flag));
+			goto insert_if;
+		    } 
+		} else if (regparse[0] >= '1' && regparse[0] <= '9' ) {
+		    parno = atoi(regparse++);
+
+		    while (isDIGIT(*regparse))
+			regparse++;
+		    ret = reganode(GROUPP, parno);
+		    if ((c = *nextchar()) != ')')
+			FAIL2("Switch (?(number%c not recognized", c);
+		  insert_if:
+		    regtail(ret, reganode(IFTHEN, 0));
+		    br = regbranch(&flags, 1);
+		    if (br == NULL)
+			br = reganode(LONGJMP, 0);
+		    else
+			regtail(br, reganode(LONGJMP, 0));
+		    c = *nextchar();
+		    if (c == '|') {
+			lastbr = reganode(IFTHEN, 0); /* Fake one for optimizer. */
+			regbranch(&flags, 1);
+			regtail(ret, lastbr);
+			c = *nextchar();
+		    } else
+			lastbr = NULL;
+		    if (c != ')')
+			FAIL("Switch (?(condition)... contains too many branches");
+		    ender = reg_node(TAIL);
+		    regtail(br, ender);
+		    if (lastbr) {
+			regtail(lastbr, ender);
+			regtail(NEXTOPER(NEXTOPER(lastbr)), ender);
+		    } else
+			regtail(ret, ender);
+		    return ret;
+		} else {
+		    FAIL2("Unknown condition for (?(%.2s", regparse);
+		}
+	    }
             case 0:
-                croak("Sequence (? incomplete");
+                FAIL("Sequence (? incomplete");
                 break;
 	    default:
 		--regparse;
 		while (*regparse && strchr("iogcmsx", *regparse))
 		    pmflag(&regflags, *regparse++);
+	      unknown:
 		if (*regparse != ')')
-		    croak("Sequence (?%c...) not recognized", *regparse);
+		    FAIL2("Sequence (?%c...) not recognized", *regparse);
 		nextchar();
 		*flagp = TRYAGAIN;
 		return NULL;
@@ -486,62 +1135,99 @@ reg(I32 paren, I32 *flagp)
 	    parno = regnpar;
 	    regnpar++;
 	    ret = reganode(OPEN, parno);
+	    open = 1;
 	}
     } else
 	ret = NULL;
 
     /* Pick up the branches, linking them together. */
-    br = regbranch(&flags);
+    br = regbranch(&flags, 1);
     if (br == NULL)
 	return(NULL);
-    if (ret != NULL)
-	regtail(ret, br);	/* OPEN -> first. */
-    else
+    if (*regparse == '|') {
+	if (!SIZE_ONLY && extralen) {
+	    reginsert(BRANCHJ, br);
+	} else
+	    reginsert(BRANCH, br);
+	have_branch = 1;
+	if (SIZE_ONLY)
+	    extralen += 1;		/* For BRANCHJ-BRANCH. */
+    } else if (paren == ':') {
+	*flagp |= flags&SIMPLE;
+    }
+    if (open) {				/* Starts with OPEN. */
+	regtail(ret, br);		/* OPEN -> first. */
+    } else if (paren != '?')		/* Not Conditional */
 	ret = br;
     if (!(flags&HASWIDTH))
 	*flagp &= ~HASWIDTH;
     *flagp |= flags&SPSTART;
+    lastbr = br;
     while (*regparse == '|') {
+	if (!SIZE_ONLY && extralen) {
+	    ender = reganode(LONGJMP,0);
+	    regtail(NEXTOPER(NEXTOPER(lastbr)), ender); /* Append to the previous. */
+	}
+	if (SIZE_ONLY)
+	    extralen += 2;		/* Account for LONGJMP. */
 	nextchar();
-	br = regbranch(&flags);
+	br = regbranch(&flags, 0);
 	if (br == NULL)
 	    return(NULL);
-	regtail(ret, br);	/* BRANCH -> BRANCH. */
+	regtail(lastbr, br);		/* BRANCH -> BRANCH. */
+	lastbr = br;
 	if (!(flags&HASWIDTH))
 	    *flagp &= ~HASWIDTH;
 	*flagp |= flags&SPSTART;
     }
 
-    /* Make a closing node, and hook it on the end. */
-    switch (paren) {
-    case ':':
-	ender = regnode(NOTHING);
-	break;
-    case 1:
-	ender = reganode(CLOSE, parno);
-	break;
-    case '=':
-    case '!':
-	ender = regnode(SUCCEED);
-	*flagp &= ~HASWIDTH;
-	break;
-    case 0:
-	ender = regnode(END);
-	break;
-    }
-    regtail(ret, ender);
-
-    /* Hook the tails of the branches to the closing node. */
-    for (br = ret; br != NULL; br = regnext(br))
-	regoptail(br, ender);
+    if (have_branch || paren != ':') {
+	/* Make a closing node, and hook it on the end. */
+	switch (paren) {
+	case ':':
+	    ender = reg_node(TAIL);
+	    break;
+	case 1:
+	    ender = reganode(CLOSE, parno);
+	    break;
+	case '<':
+	case '>':
+	case ',':
+	case '=':
+	case '!':
+	    ender = reg_node(SUCCEED);
+	    *flagp &= ~HASWIDTH;
+	    break;
+	case 0:
+	    ender = reg_node(END);
+	    break;
+	}
+	regtail(lastbr, ender);
 
-    if (paren == '=') {
-	reginsert(IFMATCH,ret);
-	regtail(ret, regnode(NOTHING));
+	if (have_branch) {
+	    /* Hook the tails of the branches to the closing node. */
+	    for (br = ret; br != NULL; br = regnext(br)) {
+		regoptail(br, ender);
+	    }
+	}
     }
-    else if (paren == '!') {
-	reginsert(UNLESSM,ret);
-	regtail(ret, regnode(NOTHING));
+
+    {
+	char *p;
+	static char parens[] = "=!<,>";
+
+	if (paren && (p = strchr(parens, paren))) {
+	    int node = ((p - parens) % 2) ? UNLESSM : IFMATCH;
+	    int flag = (p - parens) > 1;
+
+	    if (paren == '>')
+		node = SUSPEND, flag = 0;
+	    reginsert(node,ret);
+#ifdef REGALIGN_STRUCT
+	    ret->flags = flag;
+#endif 
+	    regtail(ret, reg_node(TAIL));
+	}
     }
 
     /* Check for proper termination. */
@@ -554,6 +1240,9 @@ reg(I32 paren, I32 *flagp)
 	    FAIL("junk on end of regexp");	/* "Can't happen". */
 	/* NOTREACHED */
     }
+    if (paren != 0) {
+	regflags = oregflags;
+    }
 
     return(ret);
 }
@@ -563,18 +1252,28 @@ reg(I32 paren, I32 *flagp)
  *
  * Implements the concatenation operator.
  */
-static char *
-regbranch(I32 *flagp)
+static regnode *
+regbranch(I32 *flagp, I32 first)
 {
-    register char *ret;
-    register char *chain;
-    register char *latest;
-    I32 flags = 0;
+    register regnode *ret;
+    register regnode *chain = NULL;
+    register regnode *latest;
+    I32 flags = 0, c = 0;
 
-    *flagp = WORST;		/* Tentatively. */
+    if (first) 
+	ret = NULL;
+    else {
+	if (!SIZE_ONLY && extralen) 
+	    ret = reganode(BRANCHJ,0);
+	else
+	    ret = reg_node(BRANCH);
+    }
+	
+    if (!first && SIZE_ONLY) 
+	extralen += 1;			/* BRANCHJ */
+    
+    *flagp = WORST;			/* Tentatively. */
 
-    ret = regnode(BRANCH);
-    chain = NULL;
     regparse--;
     nextchar();
     while (regparse < regxend && *regparse != '|' && *regparse != ')') {
@@ -584,18 +1283,26 @@ regbranch(I32 *flagp)
 	    if (flags & TRYAGAIN)
 		continue;
 	    return(NULL);
-	}
+	} else if (ret == NULL)
+	    ret = latest;
 	*flagp |= flags&HASWIDTH;
-	if (chain == NULL)	/* First piece. */
+	if (chain == NULL) 	/* First piece. */
 	    *flagp |= flags&SPSTART;
 	else {
 	    regnaughty++;
 	    regtail(chain, latest);
 	}
 	chain = latest;
+	c++;
+    }
+    if (chain == NULL) {	/* Loop ran zero times. */
+	chain = reg_node(NOTHING);
+	if (ret == NULL)
+	    ret = chain;
+    }
+    if (c == 1) {
+	*flagp |= flags&SIMPLE;
     }
-    if (chain == NULL)	/* Loop ran zero times. */
-	(void) regnode(NOTHING);
 
     return(ret);
 }
@@ -609,17 +1316,17 @@ regbranch(I32 *flagp)
  * It might seem that this node could be dispensed with entirely, but the
  * endmarker role is not redundant.
  */
-static char *
+static regnode *
 regpiece(I32 *flagp)
 {
-    register char *ret;
+    register regnode *ret;
     register char op;
     register char *next;
     I32 flags;
     char *origparse = regparse;
     char *maxpos;
     I32 min;
-    I32 max = 32767;
+    I32 max = REG_INFTY;
 
     ret = regatom(&flags);
     if (ret == NULL) {
@@ -629,14 +1336,6 @@ regpiece(I32 *flagp)
     }
 
     op = *regparse;
-    if (op == '(' && regparse[1] == '?' && regparse[2] == '#') {
-	while (op && op != ')')
-	    op = *++regparse;
-	if (op) {
-	    nextchar();
-	    op = *regparse;
-	}
-    }
 
     if (op == '{' && regcurly(regparse)) {
 	next = regparse + 1;
@@ -661,7 +1360,9 @@ regpiece(I32 *flagp)
 		maxpos = regparse;
 	    max = atoi(maxpos);
 	    if (!max && *maxpos != '0')
-		max = 32767;		/* meaning "infinity" */
+		max = REG_INFTY;		/* meaning "infinity" */
+	    else if (max >= REG_INFTY)
+		FAIL2("Quantifier in {,} bigger than %d", REG_INFTY - 1);
 	    regparse = next;
 	    nextchar();
 
@@ -672,23 +1373,30 @@ regpiece(I32 *flagp)
 	    }
 	    else {
 		regnaughty += 4 + regnaughty;	/* compound interest */
-		regtail(ret, regnode(WHILEM));
+		regtail(ret, reg_node(WHILEM));
+		if (!SIZE_ONLY && extralen) {
+		    reginsert(LONGJMP,ret);
+		    reginsert(NOTHING,ret);
+		    NEXT_OFF(ret) = 3;	/* Go over LONGJMP. */
+		}
 		reginsert(CURLYX,ret);
-		regtail(ret, regnode(NOTHING));
+		if (!SIZE_ONLY && extralen)
+		    NEXT_OFF(ret) = 3;	/* Go over NOTHING to LONGJMP. */
+		regtail(ret, reg_node(NOTHING));
+		if (SIZE_ONLY)
+		    extralen += 3;
 	    }
+#ifdef REGALIGN_STRUCT
+	    ret->flags = 0;
+#endif 
 
 	    if (min > 0)
 		*flagp = (WORST|HASWIDTH);
 	    if (max && max < min)
-		croak("Can't do {n,m} with n > m");
-	    if (regcode != &regdummy) {
-#ifdef REGALIGN
-		*(unsigned short *)(ret+3) = min;
-		*(unsigned short *)(ret+5) = max;
-#else
-		ret[3] = min >> 8; ret[4] = min & 0377;
-		ret[5] = max  >> 8; ret[6] = max  & 0377;
-#endif
+		FAIL("Can't do {n,m} with n > m");
+	    if (!SIZE_ONLY) {
+		ARG1_SET(ret, min);
+		ARG2_SET(ret, max);
 	    }
 
 	    goto nest_check;
@@ -700,8 +1408,10 @@ regpiece(I32 *flagp)
 	return(ret);
     }
 
+#if 0				/* Now runtime fix should be reliable. */
     if (!(flags&HASWIDTH) && op != '?')
-      FAIL("regexp *+ operand could be empty"); /* else may core dump */
+      FAIL("regexp *+ operand could be empty");
+#endif 
 
     nextchar();
 
@@ -709,6 +1419,9 @@ regpiece(I32 *flagp)
 
     if (op == '*' && (flags&SIMPLE)) {
 	reginsert(STAR, ret);
+#ifdef REGALIGN_STRUCT
+	ret->flags = 0;
+#endif 
 	regnaughty += 4;
     }
     else if (op == '*') {
@@ -716,6 +1429,9 @@ regpiece(I32 *flagp)
 	goto do_curly;
     } else if (op == '+' && (flags&SIMPLE)) {
 	reginsert(PLUS, ret);
+#ifdef REGALIGN_STRUCT
+	ret->flags = 0;
+#endif 
 	regnaughty += 3;
     }
     else if (op == '+') {
@@ -726,7 +1442,7 @@ regpiece(I32 *flagp)
 	goto do_curly;
     }
   nest_check:
-    if (dowarn && regcode != &regdummy && !(flags&HASWIDTH) && max > 10000) {
+    if (dowarn && !SIZE_ONLY && !(flags&HASWIDTH) && max > 10000) {
 	warn("%.*s matches null string many times",
 	    regparse - origparse, origparse);
     }
@@ -735,7 +1451,7 @@ regpiece(I32 *flagp)
 	nextchar();
 	reginsert(MINMOD, ret);
 #ifdef REGALIGN
-	regtail(ret, ret + 4);
+	regtail(ret, ret + NODE_STEP_REGNODE);
 #else
 	regtail(ret, ret + 3);
 #endif
@@ -756,10 +1472,10 @@ regpiece(I32 *flagp)
  *
  * [Yes, it is worth fixing, some scripts can run twice the speed.]
  */
-static char *
+static regnode *
 regatom(I32 *flagp)
 {
-    register char *ret = 0;
+    register regnode *ret = 0;
     I32 flags;
 
     *flagp = WORST;		/* Tentatively. */
@@ -767,29 +1483,32 @@ regatom(I32 *flagp)
 tryagain:
     switch (*regparse) {
     case '^':
+	seen_zerolen++;
 	nextchar();
 	if (regflags & PMf_MULTILINE)
-	    ret = regnode(MBOL);
+	    ret = reg_node(MBOL);
 	else if (regflags & PMf_SINGLELINE)
-	    ret = regnode(SBOL);
+	    ret = reg_node(SBOL);
 	else
-	    ret = regnode(BOL);
+	    ret = reg_node(BOL);
 	break;
     case '$':
+	if (regparse[1]) 
+	    seen_zerolen++;
 	nextchar();
 	if (regflags & PMf_MULTILINE)
-	    ret = regnode(MEOL);
+	    ret = reg_node(MEOL);
 	else if (regflags & PMf_SINGLELINE)
-	    ret = regnode(SEOL);
+	    ret = reg_node(SEOL);
 	else
-	    ret = regnode(EOL);
+	    ret = reg_node(EOL);
 	break;
     case '.':
 	nextchar();
 	if (regflags & PMf_SINGLELINE)
-	    ret = regnode(SANY);
+	    ret = reg_node(SANY);
 	else
-	    ret = regnode(ANY);
+	    ret = reg_node(ANY);
 	regnaughty++;
 	*flagp |= HASWIDTH|SIMPLE;
 	break;
@@ -806,7 +1525,7 @@ tryagain:
 		    goto tryagain;
 		return(NULL);
 	}
-	*flagp |= flags&(HASWIDTH|SPSTART);
+	*flagp |= flags&(HASWIDTH|SPSTART|SIMPLE);
 	break;
     case '|':
     case ')':
@@ -814,7 +1533,7 @@ tryagain:
 	    *flagp |= TRYAGAIN;
 	    return NULL;
 	}
-	croak("internal urp in regexp at /%s/", regparse);
+	FAIL2("internal urp in regexp at /%s/", regparse);
 				/* Supposed to be caught earlier. */
 	break;
     case '{':
@@ -831,57 +1550,61 @@ tryagain:
     case '\\':
 	switch (*++regparse) {
 	case 'A':
-	    ret = regnode(SBOL);
+	    seen_zerolen++;
+	    ret = reg_node(SBOL);
 	    *flagp |= SIMPLE;
 	    nextchar();
 	    break;
 	case 'G':
-	    ret = regnode(GPOS);
+	    ret = reg_node(GPOS);
+	    regseen |= REG_SEEN_GPOS;
 	    *flagp |= SIMPLE;
 	    nextchar();
 	    break;
 	case 'Z':
-	    ret = regnode(SEOL);
+	    ret = reg_node(SEOL);
 	    *flagp |= SIMPLE;
 	    nextchar();
 	    break;
 	case 'w':
-	    ret = regnode((regflags & PMf_LOCALE) ? ALNUML : ALNUM);
+	    ret = reg_node((regflags & PMf_LOCALE) ? ALNUML : ALNUM);
 	    *flagp |= HASWIDTH|SIMPLE;
 	    nextchar();
 	    break;
 	case 'W':
-	    ret = regnode((regflags & PMf_LOCALE) ? NALNUML : NALNUM);
+	    ret = reg_node((regflags & PMf_LOCALE) ? NALNUML : NALNUM);
 	    *flagp |= HASWIDTH|SIMPLE;
 	    nextchar();
 	    break;
 	case 'b':
-	    ret = regnode((regflags & PMf_LOCALE) ? BOUNDL : BOUND);
+	    seen_zerolen++;
+	    ret = reg_node((regflags & PMf_LOCALE) ? BOUNDL : BOUND);
 	    *flagp |= SIMPLE;
 	    nextchar();
 	    break;
 	case 'B':
-	    ret = regnode((regflags & PMf_LOCALE) ? NBOUNDL : NBOUND);
+	    seen_zerolen++;
+	    ret = reg_node((regflags & PMf_LOCALE) ? NBOUNDL : NBOUND);
 	    *flagp |= SIMPLE;
 	    nextchar();
 	    break;
 	case 's':
-	    ret = regnode((regflags & PMf_LOCALE) ? SPACEL : SPACE);
+	    ret = reg_node((regflags & PMf_LOCALE) ? SPACEL : SPACE);
 	    *flagp |= HASWIDTH|SIMPLE;
 	    nextchar();
 	    break;
 	case 'S':
-	    ret = regnode((regflags & PMf_LOCALE) ? NSPACEL : NSPACE);
+	    ret = reg_node((regflags & PMf_LOCALE) ? NSPACEL : NSPACE);
 	    *flagp |= HASWIDTH|SIMPLE;
 	    nextchar();
 	    break;
 	case 'd':
-	    ret = regnode(DIGIT);
+	    ret = reg_node(DIGIT);
 	    *flagp |= HASWIDTH|SIMPLE;
 	    nextchar();
 	    break;
 	case 'D':
-	    ret = regnode(NDIGIT);
+	    ret = reg_node(NDIGIT);
 	    *flagp |= HASWIDTH|SIMPLE;
 	    nextchar();
 	    break;
@@ -934,18 +1657,19 @@ tryagain:
 
     default: {
 	    register I32 len;
-	    register char ender;
+	    register U8 ender;
 	    register char *p;
-	    char *oldp;
+	    char *oldp, *s;
 	    I32 numlen;
 
 	    regparse++;
 
 	defchar:
-	    ret = regnode((regflags & PMf_FOLD)
+	    ret = reg_node((regflags & PMf_FOLD)
 			  ? ((regflags & PMf_LOCALE) ? EXACTFL : EXACTF)
 			  : EXACT);
-	    regc(0);		/* save spot for len */
+	    s = OPERAND(ret);
+	    regc(0, s++);		/* save spot for len */
 	    for (len = 0, p = regparse - 1;
 	      len < 127 && p < regxend;
 	      len++)
@@ -1043,11 +1767,11 @@ tryagain:
 			p = oldp;
 		    else {
 			len++;
-			regc(ender);
+			regc(ender, s++);
 		    }
 		    break;
 		}
-		regc(ender);
+		regc(ender, s++);
 	    }
 	loopdone:
 	    regparse = p - 1;
@@ -1058,9 +1782,16 @@ tryagain:
 		*flagp |= HASWIDTH;
 	    if (len == 1)
 		*flagp |= SIMPLE;
-	    if (regcode != &regdummy)
+	    if (!SIZE_ONLY)
 		*OPERAND(ret) = len;
-	    regc('\0');
+	    regc('\0', s++);
+	    if (SIZE_ONLY) {
+#ifdef REGALIGN_STRUCT
+		regsize += (len + 2 + sizeof(regnode) - 1) / sizeof(regnode);
+#endif 
+	    } else {
+		regcode += (len + 2 + sizeof(regnode) - 1) / sizeof(regnode);
+	    }
 	}
 	break;
     }
@@ -1088,38 +1819,41 @@ regwhite(char *p, char *e)
 static void
 regset(char *opnd, register I32 c)
 {
-    if (opnd == &regdummy)
+    if (SIZE_ONLY)
 	return;
     c &= 0xFF;
     opnd[1 + (c >> 3)] |= (1 << (c & 7));
 }
 
-static char *
+static regnode *
 regclass(void)
 {
-    register char *opnd;
+    register char *opnd, *s;
     register I32 Class;
     register I32 lastclass = 1234;
     register I32 range = 0;
-    register char *ret;
+    register regnode *ret;
     register I32 def;
     I32 numlen;
 
-    ret = regnode(ANYOF);
-    opnd = regcode;
+    s = opnd = OPERAND(regcode);
+    ret = reg_node(ANYOF);
     for (Class = 0; Class < 33; Class++)
-	regc(0);
+	regc(0, s++);
     if (*regparse == '^') {	/* Complement of range. */
 	regnaughty++;
 	regparse++;
-	if (opnd != &regdummy)
+	if (!SIZE_ONLY)
 	    *opnd |= ANYOF_INVERT;
     }
-    if (opnd != &regdummy) {
+    if (!SIZE_ONLY) {
+ 	regcode += ANY_SKIP;
 	if (regflags & PMf_FOLD)
 	    *opnd |= ANYOF_FOLD;
 	if (regflags & PMf_LOCALE)
 	    *opnd |= ANYOF_LOCALE;
+    } else {
+	regsize += ANY_SKIP;
     }
     if (*regparse == ']' || *regparse == '-')
 	goto skipcond;		/* allow 1st char to be ] or - */
@@ -1131,7 +1865,7 @@ regclass(void)
 	    switch (Class) {
 	    case 'w':
 		if (regflags & PMf_LOCALE) {
-		    if (opnd != &regdummy)
+		    if (!SIZE_ONLY)
 			*opnd |= ANYOF_ALNUML;
 		}
 		else {
@@ -1143,7 +1877,7 @@ regclass(void)
 		continue;
 	    case 'W':
 		if (regflags & PMf_LOCALE) {
-		    if (opnd != &regdummy)
+		    if (!SIZE_ONLY)
 			*opnd |= ANYOF_NALNUML;
 		}
 		else {
@@ -1155,7 +1889,7 @@ regclass(void)
 		continue;
 	    case 's':
 		if (regflags & PMf_LOCALE) {
-		    if (opnd != &regdummy)
+		    if (!SIZE_ONLY)
 			*opnd |= ANYOF_SPACEL;
 		}
 		else {
@@ -1167,7 +1901,7 @@ regclass(void)
 		continue;
 	    case 'S':
 		if (regflags & PMf_LOCALE) {
-		    if (opnd != &regdummy)
+		    if (!SIZE_ONLY)
 			*opnd |= ANYOF_NSPACEL;
 		}
 		else {
@@ -1279,40 +2013,33 @@ nextchar(void)
 }
 
 /*
-- regnode - emit a node
+- reg_node - emit a node
 */
+static regnode *			/* Location. */
 #ifdef CAN_PROTOTYPE
-static char *			/* Location. */
-regnode(char op)
+reg_node(U8 op)
 #else
-static char *			/* Location. */
-regnode(op)
-char op;
+reg_node(op)
+U8 op;
 #endif
 {
-    register char *ret;
-    register char *ptr;
+    register regnode *ret;
+    register regnode *ptr;
 
     ret = regcode;
-    if (ret == &regdummy) {
-#ifdef REGALIGN
-	if (!(regsize & 1))
-	    regsize++;
-#endif
+    if (SIZE_ONLY) {
+	SIZE_ALIGN(regsize);
+#ifdef REGALIGN_STRUCT
+	regsize += 1;
+#else
 	regsize += 3;
+#endif 
 	return(ret);
     }
 
-#ifdef REGALIGN
-#ifndef lint
-    if (!((long)ret & 1))
-      *ret++ = 127;
-#endif
-#endif
+    NODE_ALIGN_FILL(ret);
     ptr = ret;
-    *ptr++ = op;
-    *ptr++ = '\0';		/* Null "next" pointer. */
-    *ptr++ = '\0';
+    FILL_ADVANCE_NODE(ptr, op);
     regcode = ptr;
 
     return(ret);
@@ -1321,45 +2048,32 @@ char op;
 /*
 - reganode - emit a node with an argument
 */
+static regnode *			/* Location. */
 #ifdef CAN_PROTOTYPE
-static char *			/* Location. */
-reganode(char op, unsigned short arg)
+reganode(U8 op, U32 arg)
 #else
-static char *			/* Location. */
 reganode(op, arg)
-char op;
-unsigned short arg;
+U8 op;
+U32 arg;
 #endif
 {
-    register char *ret;
-    register char *ptr;
+    register regnode *ret;
+    register regnode *ptr;
 
     ret = regcode;
-    if (ret == &regdummy) {
+    if (SIZE_ONLY) {
+	SIZE_ALIGN(regsize);
 #ifdef REGALIGN
-	if (!(regsize & 1))
-	    regsize++;
-#endif
+	regsize += 2;
+#else
 	regsize += 5;
+#endif 
 	return(ret);
     }
 
-#ifdef REGALIGN
-#ifndef lint
-    if (!((long)ret & 1))
-      *ret++ = 127;
-#endif
-#endif
+    NODE_ALIGN_FILL(ret);
     ptr = ret;
-    *ptr++ = op;
-    *ptr++ = '\0';		/* Null "next" pointer. */
-    *ptr++ = '\0';
-#ifdef REGALIGN
-    *(unsigned short *)(ret+3) = arg;
-#else
-    ret[3] = arg >> 8; ret[4] = arg & 0377;
-#endif
-    ptr += 2;
+    FILL_ADVANCE_NODE_ARG(ptr, op, arg);
     regcode = ptr;
 
     return(ret);
@@ -1370,17 +2084,16 @@ unsigned short arg;
 */
 #ifdef CAN_PROTOTYPE
 static void
-regc(char b)
+regc(U8 b, char* s)
 #else
 static void
-regc(b)
-char b;
+regc(b, s)
+U8 b;
+char *s;
 #endif
 {
-    if (regcode != &regdummy)
-	*regcode++ = b;
-    else
-	regsize++;
+    if (!SIZE_ONLY)
+	*s = b;
 }
 
 /*
@@ -1390,60 +2103,52 @@ char b;
 */
 #ifdef CAN_PROTOTYPE
 static void
-reginsert(char op, char *opnd)
+reginsert(U8 op, regnode *opnd)
 #else
 static void
 reginsert(op, opnd)
-char op;
-char *opnd;
+U8 op;
+regnode *opnd;
 #endif
 {
-    register char *src;
-    register char *dst;
-    register char *place;
-    register int offset = (regkind[(U8)op] == CURLY ? 4 : 0);
-
-    if (regcode == &regdummy) {
-#ifdef REGALIGN
-	regsize += 4 + offset;
-#else
-	regsize += 3 + offset;
-#endif
+    register regnode *src;
+    register regnode *dst;
+    register regnode *place;
+    register int offset = regarglen[(U8)op];
+    
+/* (regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
+
+    if (SIZE_ONLY) {
+	regsize += NODE_STEP_REGNODE + offset;
 	return;
     }
 
     src = regcode;
-#ifdef REGALIGN
-    regcode += 4 + offset;
-#else
-    regcode += 3 + offset;
-#endif
+    regcode += NODE_STEP_REGNODE + offset;
     dst = regcode;
     while (src > opnd)
-	*--dst = *--src;
+	StructCopy(--src, --dst, regnode);
 
     place = opnd;		/* Op node, where operand used to be. */
-    *place++ = op;
-    *place++ = '\0';
-    *place++ = '\0';
-    while (offset-- > 0)
-	*place++ = '\0';
-#ifdef REGALIGN
-    *place++ = '\177';
+    src = NEXTOPER(place);
+    FILL_ADVANCE_NODE(place, op);
+    Zero(src, offset, regnode);
+#if defined(REGALIGN) && !defined(REGALIGN_STRUCT)
+    src[offset + 1] = '\177';
 #endif
 }
 
 /*
-- regtail - set the next-pointer at the end of a node chain
+- regtail - set the next-pointer at the end of a node chain of p to val.
 */
 static void
-regtail(char *p, char *val)
+regtail(regnode *p, regnode *val)
 {
-    register char *scan;
-    register char *temp;
+    register regnode *scan;
+    register regnode *temp;
     register I32 offset;
 
-    if (p == &regdummy)
+    if (SIZE_ONLY)
 	return;
 
     /* Find last node. */
@@ -1456,12 +2161,18 @@ regtail(char *p, char *val)
     }
 
 #ifdef REGALIGN
+#  ifdef REGALIGN_STRUCT
+    if (reg_off_by_arg[OP(scan)]) {
+	ARG_SET(scan, val - scan);
+    } else {
+	NEXT_OFF(scan) = val - scan;
+    }
+#  else
     offset = val - scan;
-#ifndef lint
+#    ifndef lint
     *(short*)(scan+1) = offset;
-#else
-    offset = offset;
-#endif
+#    endif
+#endif 
 #else
     if (OP(scan) == BACK)
 	offset = scan - val;
@@ -1476,12 +2187,17 @@ regtail(char *p, char *val)
 - regoptail - regtail on operand of first argument; nop if operandless
 */
 static void
-regoptail(char *p, char *val)
+regoptail(regnode *p, regnode *val)
 {
     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
-    if (p == NULL || p == &regdummy || regkind[(U8)OP(p)] != BRANCH)
+    if (p == NULL || SIZE_ONLY)
+	return;
+    if (regkind[(U8)OP(p)] == BRANCH) {
+	regtail(NEXTOPER(p), val);
+    } else if ( regkind[(U8)OP(p)] == BRANCHJ) {
+	regtail(NEXTOPER(NEXTOPER(p)), val);
+    } else
 	return;
-    regtail(NEXTOPER(p), val);
 }
 
 /*
@@ -1507,55 +2223,104 @@ regcurly(register char *s)
 
 #ifdef DEBUGGING
 
+static regnode *
+dumpuntil(regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
+{
+    register char op = EXACT;	/* Arbitrary non-END op. */
+    register regnode *next, *onode;
+
+    while (op != END && (!last || node < last)) {
+	/* While that wasn't END last time... */
+
+	NODE_ALIGN(node);
+	op = OP(node);
+	if (op == CLOSE)
+	    l--;	
+	next = regnext(node);
+	/* Where, what. */
+	if (OP(node) == OPTIMIZED)
+	    goto after_print;
+	regprop(sv, node);
+	PerlIO_printf(Perl_debug_log, "%4d%*s%s", node - start, 
+		      2*l + 1, "", SvPVX(sv));
+	if (next == NULL)		/* Next ptr. */
+	    PerlIO_printf(Perl_debug_log, "(0)");
+	else 
+	    PerlIO_printf(Perl_debug_log, "(%d)", next - start);
+	(void)PerlIO_putc(Perl_debug_log, '\n');
+      after_print:
+	if (regkind[(U8)op] == BRANCHJ) {
+	    register regnode *nnode = (OP(next) == LONGJMP 
+				       ? regnext(next) 
+				       : next);
+	    if (last && nnode > last)
+		nnode = last;
+	    node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
+	} else if (regkind[(U8)op] == BRANCH) {
+	    node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
+	} else if ( op == CURLY) {   /* `next' might be very big: optimizer */
+	    node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
+			     NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
+	} else if (regkind[(U8)op] == CURLY && op != CURLYX) {
+	    node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
+			     next, sv, l + 1);
+	} else if ( op == PLUS || op == STAR) {
+	    node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
+	} else if (op == ANYOF) {
+	    node = NEXTOPER(node);
+	    node += ANY_SKIP;
+	} else if (regkind[(U8)op] == EXACT) {
+            /* Literal string, where present. */
+	    node += ((*OPERAND(node)) + 2 + sizeof(regnode) - 1) / sizeof(regnode);
+	    node = NEXTOPER(node);
+	} else {
+	    node = NEXTOPER(node);
+	    node += regarglen[(U8)op];
+	}
+	if (op == CURLYX || op == OPEN)
+	    l++;
+	else if (op == WHILEM)
+	    l--;
+    }
+    return node;
+}
+
 /*
  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
  */
 void
 regdump(regexp *r)
 {
-    register char *s;
-    register char op = EXACT;	/* Arbitrary non-END op. */
-    register char *next;
     SV *sv = sv_newmortal();
 
-    s = r->program + 1;
-    while (op != END) {	/* While that wasn't END last time... */
-#ifdef REGALIGN
-	if (!((long)s & 1))
-	    s++;
-#endif
-	op = OP(s);
-	/* where, what */
-	regprop(sv, s);
-	PerlIO_printf(Perl_debug_log, "%2ld%s", (long)(s - r->program), SvPVX(sv));
-	next = regnext(s);
-	s += regarglen[(U8)op];
-	if (next == NULL)		/* Next ptr. */
-	    PerlIO_printf(Perl_debug_log, "(0)");
-	else 
-	    PerlIO_printf(Perl_debug_log, "(%ld)", (long)(s-r->program)+(next-s));
-	s += 3;
-	if (op == ANYOF) {
-	    s += 33;
-	}
-	if (regkind[(U8)op] == EXACT) {
-	    /* Literal string, where present. */
-	    s++;
-	    (void)PerlIO_putc(Perl_debug_log, ' ');
-	    (void)PerlIO_putc(Perl_debug_log, '<');
-	    while (*s != '\0') {
-		(void)PerlIO_putc(Perl_debug_log,*s);
-		s++;
-	    }
-	    (void)PerlIO_putc(Perl_debug_log, '>');
-	    s++;
-	}
-	(void)PerlIO_putc(Perl_debug_log, '\n');
-    }
+    (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
 
     /* Header fields of interest. */
-    if (r->regstart)
-	PerlIO_printf(Perl_debug_log, "start `%s' ", SvPVX(r->regstart));
+    if (r->anchored_substr)
+	PerlIO_printf(Perl_debug_log, "anchored `%s%s%s'%s at %d ", 
+		      colors[0],
+		      SvPVX(r->anchored_substr), 
+		      colors[1],
+		      SvTAIL(r->anchored_substr) ? "$" : "",
+		      r->anchored_offset);
+    if (r->float_substr)
+	PerlIO_printf(Perl_debug_log, "floating `%s%s%s'%s at %d..%u ", 
+		      colors[0],
+		      SvPVX(r->float_substr), 
+		      colors[1],
+		      SvTAIL(r->float_substr) ? "$" : "",
+		      r->float_min_offset, r->float_max_offset);
+    if (r->check_substr)
+	PerlIO_printf(Perl_debug_log, 
+		      r->check_substr == r->float_substr 
+		      ? "(checking floating" : "(checking anchored");
+    if (r->reganch & ROPT_NOSCAN)
+	PerlIO_printf(Perl_debug_log, " noscan");
+    if (r->reganch & ROPT_CHECK_ALL)
+	PerlIO_printf(Perl_debug_log, " isall");
+    if (r->check_substr)
+	PerlIO_printf(Perl_debug_log, ") ");
+
     if (r->regstclass) {
 	regprop(sv, r->regstclass);
 	PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
@@ -1564,17 +2329,18 @@ regdump(regexp *r)
 	PerlIO_printf(Perl_debug_log, "anchored");
 	if (r->reganch & ROPT_ANCH_BOL)
 	    PerlIO_printf(Perl_debug_log, "(BOL)");
+	if (r->reganch & ROPT_ANCH_MBOL)
+	    PerlIO_printf(Perl_debug_log, "(MBOL)");
 	if (r->reganch & ROPT_ANCH_GPOS)
 	    PerlIO_printf(Perl_debug_log, "(GPOS)");
 	PerlIO_putc(Perl_debug_log, ' ');
     }
+    if (r->reganch & ROPT_GPOS_SEEN)
+	PerlIO_printf(Perl_debug_log, "GPOS ");
     if (r->reganch & ROPT_SKIP)
 	PerlIO_printf(Perl_debug_log, "plus ");
     if (r->reganch & ROPT_IMPLICIT)
 	PerlIO_printf(Perl_debug_log, "implicit ");
-    if (r->regmust != NULL)
-	PerlIO_printf(Perl_debug_log, "must have \"%s\" back %ld ", SvPVX(r->regmust),
-	 (long) r->regback);
     PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
     PerlIO_printf(Perl_debug_log, "\n");
 }
@@ -1583,7 +2349,7 @@ regdump(regexp *r)
 - regprop - printable representation of opcode
 */
 void
-regprop(SV *sv, char *o)
+regprop(SV *sv, regnode *o)
 {
     register char *p = 0;
 
@@ -1620,17 +2386,20 @@ regprop(SV *sv, char *o)
 	p = "BRANCH";
 	break;
     case EXACT:
-	p = "EXACT";
+	sv_catpvf(sv, "EXACT <%s%s%s>", colors[0], OPERAND(o) + 1, colors[1]);
 	break;
     case EXACTF:
-	p = "EXACTF";
+	sv_catpvf(sv, "EXACTF <%s%s%s>", colors[0], OPERAND(o) + 1, colors[1]);
 	break;
     case EXACTFL:
-	p = "EXACTFL";
+	sv_catpvf(sv, "EXACTFL <%s%s%s>", colors[0], OPERAND(o) + 1, colors[1]);
 	break;
     case NOTHING:
 	p = "NOTHING";
 	break;
+    case TAIL:
+	p = "TAIL";
+	break;
     case BACK:
 	p = "BACK";
 	break;
@@ -1652,23 +2421,37 @@ regprop(SV *sv, char *o)
     case CURLY:
 	sv_catpvf(sv, "CURLY {%d,%d}", ARG1(o), ARG2(o));
 	break;
+    case CURLYM:
+#ifdef REGALIGN_STRUCT
+	sv_catpvf(sv, "CURLYM[%d] {%d,%d}", o->flags, ARG1(o), ARG2(o));
+#else
+	sv_catpvf(sv, "CURLYM {%d,%d}", ARG1(o), ARG2(o));
+#endif 
+	break;
+    case CURLYN:
+#ifdef REGALIGN_STRUCT
+	sv_catpvf(sv, "CURLYN[%d] {%d,%d}", o->flags, ARG1(o), ARG2(o));
+#else
+	sv_catpvf(sv, "CURLYN {%d,%d}", ARG1(o), ARG2(o));
+#endif 
+	break;
     case CURLYX:
 	sv_catpvf(sv, "CURLYX {%d,%d}", ARG1(o), ARG2(o));
 	break;
     case REF:
-	sv_catpvf(sv, "REF%d", ARG1(o));
+	sv_catpvf(sv, "REF%d", ARG(o));
 	break;
     case REFF:
-	sv_catpvf(sv, "REFF%d", ARG1(o));
+	sv_catpvf(sv, "REFF%d", ARG(o));
 	break;
     case REFFL:
-	sv_catpvf(sv, "REFFL%d", ARG1(o));
+	sv_catpvf(sv, "REFFL%d", ARG(o));
 	break;
     case OPEN:
-	sv_catpvf(sv, "OPEN%d", ARG1(o));
+	sv_catpvf(sv, "OPEN%d", ARG(o));
 	break;
     case CLOSE:
-	sv_catpvf(sv, "CLOSE%d", ARG1(o));
+	sv_catpvf(sv, "CLOSE%d", ARG(o));
 	p = NULL;
 	break;
     case STAR:
@@ -1684,10 +2467,18 @@ regprop(SV *sv, char *o)
 	p = "GPOS";
 	break;
     case UNLESSM:
+#ifdef REGALIGN_STRUCT
+	sv_catpvf(sv, "UNLESSM[-%d]", o->flags);
+#else
 	p = "UNLESSM";
+#endif 
 	break;
     case IFMATCH:
+#ifdef REGALIGN_STRUCT
+	sv_catpvf(sv, "IFMATCH[-%d]", o->flags);
+#else
 	p = "IFMATCH";
+#endif 
 	break;
     case SUCCEED:
 	p = "SUCCEED";
@@ -1725,6 +2516,33 @@ regprop(SV *sv, char *o)
     case NSPACEL:
 	p = "NSPACEL";
 	break;
+    case EVAL:
+	p = "EVAL";
+	break;
+    case LONGJMP:
+	p = "LONGJMP";
+	break;
+    case BRANCHJ:
+	p = "BRANCHJ";
+	break;
+    case IFTHEN:
+	p = "IFTHEN";
+	break;
+    case GROUPP:
+	sv_catpvf(sv, "GROUPP%d", ARG(o));
+	break;
+    case LOGICAL:
+	p = "LOGICAL";
+	break;
+    case SUSPEND:
+	p = "SUSPEND";
+	break;
+    case RENUM:
+	p = "RENUM";
+	break;
+    case OPTIMIZED:
+	p = "OPTIMIZED";
+	break;
     default:
 	FAIL("corrupted regexp opcode");
     }
@@ -1736,25 +2554,106 @@ regprop(SV *sv, char *o)
 void
 pregfree(struct regexp *r)
 {
-    if (!r)
+    if (!r || (--r->refcnt > 0))
 	return;
-    if (r->precomp) {
+    if (r->precomp)
 	Safefree(r->precomp);
-	r->precomp = Nullch;
-    }
-    if (r->subbase) {
+    if (r->subbase)
 	Safefree(r->subbase);
-	r->subbase = Nullch;
-    }
-    if (r->regmust) {
-	SvREFCNT_dec(r->regmust);
-	r->regmust = Nullsv;
-    }
-    if (r->regstart) {
-	SvREFCNT_dec(r->regstart);
-	r->regstart = Nullsv;
+    if (r->anchored_substr)
+	SvREFCNT_dec(r->anchored_substr);
+    if (r->float_substr)
+	SvREFCNT_dec(r->float_substr);
+    if (r->data) {
+	int n = r->data->count;
+	while (--n >= 0) {
+	    switch (r->data->what[n]) {
+	    case 's':
+		SvREFCNT_dec((SV*)r->data->data[n]);
+		break;
+	    case 'o':
+		op_free((OP_4tree*)r->data->data[n]);
+		break;
+	    case 'n':
+		break;
+	    default:
+		FAIL2("panic: regfree data code '%c'", r->data->what[n]);
+	    }
+	}
+	Safefree(r->data->what);
+	Safefree(r->data);
     }
     Safefree(r->startp);
     Safefree(r->endp);
     Safefree(r);
 }
+
+/*
+ - regnext - dig the "next" pointer out of a node
+ *
+ * [Note, when REGALIGN is defined there are two places in regmatch()
+ * that bypass this code for speed.]
+ */
+regnode *
+regnext(register regnode *p)
+{
+    register I32 offset;
+
+    if (p == &regdummy)
+	return(NULL);
+
+    offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
+    if (offset == 0)
+	return(NULL);
+
+#ifdef REGALIGN
+    return(p+offset);
+#else
+    if (OP(p) == BACK)
+	return(p-offset);
+    else
+	return(p+offset);
+#endif
+}
+
+#ifdef I_STDARG
+void	
+re_croak2(const char* pat1,const char* pat2,...)
+#else
+/*VARARGS0*/
+void	
+re_croak2(const char* pat1,const char* pat2, va_alist)
+    const char* pat1;
+    const char* pat2;
+    va_dcl
+#endif 
+{
+    va_list args;
+    STRLEN l1 = strlen(pat1);
+    STRLEN l2 = strlen(pat2);
+    char buf[512];
+    char *message;
+
+    if (l1 > 510)
+	l1 = 510;
+    if (l1 + l2 > 510)
+	l2 = 510 - l1;
+    Copy(pat1, buf, l1 , char);
+    Copy(pat2, buf + l1, l2 , char);
+    buf[l1 + l2 + 1] = '\n';
+    buf[l1 + l2 + 2] = '\0';
+#ifdef I_STDARG
+    va_start(args, pat2);
+#else
+    va_start(args);
+#endif
+    message = mess(buf, &args);
+    va_end(args);
+    l1 = strlen(message);
+    if (l1 > 512)
+	l1 = 512;
+    Copy(message, buf, l1 , char);
+    buf[l1] = '\0';			/* Overwrite \n */
+    croak("%s", buf);
+}
+