ash: speed up ${v//pattern/repl}

function                                             old     new   delta
subevalvar                                          1447    1457     +10

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 10 insertions, 7 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 092f3bcc7..b5947147a 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -7284,7 +7284,7 @@ subevalvar(char *start, char *str, int strloc,
                 while (idx <= end) {
  try_to_match:
                         if (no_meta_len == 0) {
-                                /* pattern has meta chars, have to glob; or ENABLE_ASH_OPTIMIZE_FOR_SIZE  */
+                                /* pattern has meta chars, have to glob; or ENABLE_ASH_OPTIMIZE_FOR_SIZE */
                                 loc = scanright(idx, rmesc, rmescend, str, quotes, /*match_at_start:*/ 1);
                         } else {
                                 /* Testcase for very slow replace (performs about 22k replaces):
@@ -7292,16 +7292,19 @@ subevalvar(char *start, char *str, int strloc,
                                  * x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;echo ${#x}
                                  * echo "${x//:/|}"
                                  */
-                                size_t n;
                                 if (strncmp(rmesc, str, no_meta_len) != 0)
                                         goto no_match;
-                                n = no_meta_len;
                                 loc = idx;
-                                do {
-                                        if (quotes && (unsigned char)*loc == CTLESC)
+                                if (!quotes) {
+                                        loc += no_meta_len;
+                                } else {
+                                        size_t n = no_meta_len;
+                                        do {
+                                                if ((unsigned char)*loc == CTLESC)
+                                                        loc++;
                                                 loc++;
-                                        loc++;
-                                } while (--n != 0);
+                                        } while (--n != 0);
+                                }
                         }
                         //bb_error_msg("scanright('%s'):'%s'", str, loc);
                         if (!loc) {