Apply performance improvement to short byte array search.

* re.c (rb_memsearch_ss): Apply performance improvement to short
  byte array search for platforms without memmem(3).
  [Feature #6311] [ruby-dev:45530]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37793 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 0 deletions

diff --git a/re.c b/re.c
index 97803d4e38..8fa1abc0e6 100644
--- a/re.c
+++ b/re.c
@@ -126,6 +126,9 @@ rb_memsearch_ss(const unsigned char *xs, long m, const unsigned char *ys, long n
     if (m > SIZEOF_VALUE)
 	rb_bug("!!too long pattern string!!");
 
+    if (!(y = memchr(y, *x, n - m + 1)))
+	return -1;
+
     /* Prepare hash value */
     for (hx = *x++, hy = *y++; x < xe; ++x, ++y) {
 	hx <<= CHAR_BIT;