regmatch(): remove reginput from CURLY etc

reginput mostly tracked locinput, except when regrepeat() was called.
With a bit of jiggling, it could be eliminated for these blocks of code.

This is part of a campaign to eliminate the reginput variable.

diff --git a/regexec.c b/regexec.c
index 9c423ed..c2aba47 100644 (file)
--- a/regexec.c
+++ b/regexec.c
@@ -5496,17 +5496,14 @@ NULL
 
            ST.A = scan;
            ST.B = next;
-           reginput = locinput;
            if (minmod) {
-                /* avoid taking address of reginput, so it can remain
-                 * a register var */
-                char *ri = reginput;
+                char *li = locinput;
                minmod = 0;
-               if (ST.min && regrepeat(rex, &ri, ST.A, ST.min, depth) < ST.min)
+               if (ST.min && regrepeat(rex, &li, ST.A, ST.min, depth) < ST.min)
                    sayNO;
-                reginput = ri;
+                locinput = li;
+                nextchr = UCHARAT(locinput);
                ST.count = ST.min;
-               locinput = reginput;
                REGCP_SET(ST.cp);
                if (ST.c1 == CHRTEST_VOID)
                    goto curly_try_B_min;
@@ -5536,12 +5533,14 @@ NULL
 
            }
            else {
-                char *ri = reginput;
-               ST.count = regrepeat(rex, &ri, ST.A, ST.max, depth);
-                reginput = ri;
-               locinput = reginput;
+                /* avoid taking address of locinput, so it can remain
+                 * a register var */
+                char *li = locinput;
+               ST.count = regrepeat(rex, &li, ST.A, ST.max, depth);
                if (ST.count < ST.min)
                    sayNO;
+                locinput = li;
+                nextchr = UCHARAT(locinput);
                if ((ST.count > ST.min)
                    && (PL_regkind[OP(ST.B)] == EOL) && (OP(ST.B) != MEOL))
                {
@@ -5551,7 +5550,7 @@ NULL
                    /* ...except that $ and \Z can match before *and* after
                       newline at the end.  Consider "\n\n" =~ /\n+\Z\n/.
                       We may back off by one in this case. */
-                   if (UCHARAT(reginput - 1) == '\n' && OP(ST.B) != EOS)
+                   if (UCHARAT(locinput - 1) == '\n' && OP(ST.B) != EOS)
                        ST.min--;
                }
                REGCP_SET(ST.cp);
@@ -5563,7 +5562,6 @@ NULL
        case CURLY_B_min_known_fail:
            /* failed to find B in a non-greedy match where c1,c2 valid */
 
-           reginput = locinput;        /* Could be reset... */
            REGCP_UNWIND(ST.cp);
             if (ST.paren) {
                 UNWIND_PAREN(ST.lastparen, ST.lastcloseparen);
@@ -5622,15 +5620,16 @@ NULL
                }
                if (locinput > ST.maxpos)
                    sayNO;
-               /* reginput == oldloc now */
                if (n) {
-                    char *ri = reginput;
+                    /* In /a{m,n}b/, ST.oldloc is at "a" x m, locinput is
+                     * at b; check that everything between oldloc and
+                     * locinput matches */
+                    char *li = ST.oldloc;
                    ST.count += n;
-                   if (regrepeat(rex, &ri, ST.A, n, depth) < n)
+                   if (regrepeat(rex, &li, ST.A, n, depth) < n)
                        sayNO;
-                    reginput = ri;
+                    assert(n == REG_INFTY || locinput == li);
                }
-               reginput = locinput;
                CURLY_SETPAREN(ST.paren, ST.count);
                if (cur_eval && cur_eval->u.eval.close_paren && 
                    cur_eval->u.eval.close_paren == (U32)ST.paren) {
@@ -5649,17 +5648,15 @@ NULL
                 UNWIND_PAREN(ST.lastparen, ST.lastcloseparen);
             }
            /* failed -- move forward one */
-           reginput = locinput;
             {
-                char *ri = reginput;
-                if (!regrepeat(rex, &ri, ST.A, 1, depth)) {
+                char *li = locinput;
+                if (!regrepeat(rex, &li, ST.A, 1, depth)) {
                     sayNO;
                 }
-                reginput = ri;
+                locinput = li;
             }
             {
                ST.count++;
-               locinput = reginput;
                if (ST.count <= ST.max || (ST.max == REG_INFTY &&
                        ST.count > 0)) /* count overflow ? */
                {
@@ -5684,9 +5681,9 @@ NULL
            {
                UV c = 0;
                if (ST.c1 != CHRTEST_VOID)
-                   c = utf8_target ? utf8n_to_uvchr((U8*)reginput,
+                   c = utf8_target ? utf8n_to_uvchr((U8*)locinput,
                                           UTF8_MAXBYTES, 0, uniflags)
-                               : (UV) UCHARAT(reginput);
+                               : (UV) UCHARAT(locinput);
                /* If it could work, try it. */
                if (ST.c1 == CHRTEST_VOID || c == (UV)ST.c1 || c == (UV)ST.c2) {
                    CURLY_SETPAREN(ST.paren, ST.count);
@@ -5705,7 +5702,7 @@ NULL
            /*  back up. */
            if (--ST.count < ST.min)
                sayNO;
-           reginput = locinput = HOPc(locinput, -1);
+           locinput = HOPc(locinput, -1);
            goto curly_try_B_max;
 
 #undef ST