Eliminate precomp from struct regexp. Store the offset of precomp from

wrapped in pre_prefix, a 4 bit value. (Maybe only for now) reduce
seen_evals from I32 to 28 bits. Will anyone have more than 268435456
eval groups in a regexp?

p4raw-id: //depot/perl@32755

2 files changed, 5 insertions, 8 deletions

diff --git a/regcomp.c b/regcomp.c
index 544bbbc9d0..481d3a626e 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -4319,7 +4319,8 @@ redo_first_pass:
 
         *p++ = ':';
         Copy(RExC_precomp, p, RX_PRELEN(r), char);
-        RX_PRECOMP(r) = p;
+	assert ((r->wrapped - p) < 16);
+	r->pre_prefix = p - r->wrapped;
         p += RX_PRELEN(r);
         if (has_runon)
             *p++ = '\n';
@@ -9371,7 +9372,6 @@ Perl_re_dup(pTHX_ const regexp *r, CLONE_PARAMS *param)
     dVAR;
     regexp *ret;
     I32 npar;
-    U32 precomp_offset;
 
     if (!r)
 	return (REGEXP *)NULL;
@@ -9420,10 +9420,7 @@ Perl_re_dup(pTHX_ const regexp *r, CLONE_PARAMS *param)
 	}
     }
 
-    precomp_offset = RX_PRECOMP(ret) - ret->wrapped;
-
     ret->wrapped        = SAVEPVN(ret->wrapped, ret->wraplen+1);
-    RX_PRECOMP(ret)     = ret->wrapped + precomp_offset;
     ret->paren_names    = hv_dup_inc(ret->paren_names, param);
 
     if (ret->pprivate)
diff --git a/regexp.h b/regexp.h
index ce3a48528b..5b58697bf1 100644
--- a/regexp.h
+++ b/regexp.h
@@ -99,11 +99,11 @@ typedef struct regexp {
         
         /* Information about the match that isn't often used */
 	I32 prelen;		/* length of precomp */
-	const char *precomp;	/* pre-compilation regular expression */
 	/* wrapped can't be const char*, as it is returned by sv_2pv_flags */
 	char *wrapped;          /* wrapped version of the pattern */
 	I32 wraplen;		/* length of wrapped */
-	I32 seen_evals;         /* number of eval groups in the pattern - for security checks */ 
+	unsigned pre_prefix:4;	/* offset from wrapped to the start of precomp */
+	unsigned seen_evals:28;	/* number of eval groups in the pattern - for security checks */ 
         HV *paren_names;	/* Optional hash of paren names */
         
         /* Refcount of this regexp */
@@ -354,7 +354,7 @@ and check for NULL.
 					 : RX_MATCH_COPIED_off(prog))
 
 /* For source compatibility. We used to store these explicitly.  */
-#define RX_PRECOMP(prog)		((prog)->precomp)
+#define RX_PRECOMP(prog)		((prog)->wrapped + (prog)->pre_prefix)
 #define RX_PRELEN(prog)			((prog)->prelen)
 
 #endif /* PLUGGABLE_RE_EXTENSION */