regcppush(): don't bother saving each paren number

regcppush() saves a contiguous range of slots in rex->offs[].
Currently it saves the index (paren number) along with each slot's data.
Since we know the top index (the saved PL_regsize) and the number of
elements, on restoring we can deduce each paren number without saving it.

diff --git a/regexec.c b/regexec.c
index 243387f..1a2b19a 100644 (file)
--- a/regexec.c
+++ b/regexec.c
@@ -332,7 +332,7 @@
 
 static void restore_pos(pTHX_ void *arg);
 
-#define REGCP_PAREN_ELEMS 4
+#define REGCP_PAREN_ELEMS 3
 #define REGCP_OTHER_ELEMS 3
 #define REGCP_FRAME_ELEMS 1
 /* REGCP_FRAME_ELEMS are not part of the REGCP_OTHER_ELEMS and
@@ -346,7 +346,7 @@ S_regcppush(pTHX_ const regexp *rex, I32 parenfloor)
     const int paren_elems_to_push = (PL_regsize - parenfloor) * REGCP_PAREN_ELEMS;
     const UV total_elems = paren_elems_to_push + REGCP_OTHER_ELEMS;
     const UV elems_shifted = total_elems << SAVE_TIGHT_SHIFT;
-    int p;
+    I32 p;
     GET_RE_DEBUG_FLAGS_DECL;
 
     PERL_ARGS_ASSERT_REGCPPUSH;
@@ -370,12 +370,11 @@ S_regcppush(pTHX_ const regexp *rex, I32 parenfloor)
                PTR2UV(rex->offs)
            );
     );
-    for (p = PL_regsize; p > parenfloor; p--) {
+    for (p = parenfloor+1; p <= (I32)PL_regsize;  p++) {
 /* REGCP_PARENS_ELEMS are pushed per pairs of parentheses. */
        SSPUSHINT(rex->offs[p].end);
        SSPUSHINT(rex->offs[p].start);
        SSPUSHINT(rex->offs[p].start_tmp);
-       SSPUSHINT(p);
        DEBUG_BUFFERS_r(PerlIO_printf(Perl_debug_log,
            "    \\%"UVuf": %"IVdf"(%"IVdf")..%"IVdf"\n",
            (UV)p,
@@ -414,6 +413,7 @@ S_regcppop(pTHX_ regexp *rex)
 {
     dVAR;
     UV i;
+    U32 paren;
     GET_RE_DEBUG_FLAGS_DECL;
 
     PERL_ARGS_ASSERT_REGCPPOP;
@@ -436,9 +436,9 @@ S_regcppop(pTHX_ regexp *rex)
                PTR2UV(rex->offs)
            );
     );
+    paren = PL_regsize;
     for ( ; i > 0; i -= REGCP_PAREN_ELEMS) {
        I32 tmps;
-       U32 paren = (U32)SSPOPINT;
        rex->offs[paren].start_tmp = SSPOPINT;
        rex->offs[paren].start = SSPOPINT;
        tmps = SSPOPINT;
@@ -452,6 +452,7 @@ S_regcppop(pTHX_ regexp *rex)
            (IV)rex->offs[paren].end,
            (paren > rex->lastparen ? "(skipped)" : ""));
        );
+       paren--;
     }
 #if 1
     /* It would seem that the similar code in regtry()