2 files changed, 18 insertions, 7 deletions
diff --git a/ChangeLog b/ChangeLog
index 018a11d95f..94bf52db4f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Feb 10 13:03:29 2010  Yukihiro Matsumoto  <[email protected]>
+
+	* string.c (rb_str_times): backport r15514 to reduce loop
+	  overhead.
+
 Sun Feb  7 04:02:08 2010  Akinori MUSHA  <[email protected]>
 
 	* parse.y: Get rid of tags for Ripper, pointless in 1.8.
diff --git a/string.c b/string.c
index d3db9fca25..3df5415106 100644
--- a/string.c
+++ b/string.c
@@ -428,7 +428,8 @@ rb_str_times(str, times)
     VALUE times;
 {
     VALUE str2;
-    long i, len;
+    long n, len;
+    char *ptr2;
 
     len = NUM2LONG(times);
     if (len < 0) {
@@ -439,12 +440,17 @@ rb_str_times(str, times)
     }
 
     str2 = rb_str_new5(str,0, len *= RSTRING(str)->len);
-    for (i = 0; i < len; i += RSTRING(str)->len) {
-	memcpy(RSTRING(str2)->ptr + i,
-	       RSTRING(str)->ptr, RSTRING(str)->len);
-    }
-    RSTRING(str2)->ptr[RSTRING(str2)->len] = '\0';
-
+    ptr2 = RSTRING_PTR(str2);
+    if (len) {
+        n = RSTRING_LEN(str);
+        memcpy(ptr2, RSTRING_PTR(str), n);
+        while (n <= len/2) {
+            memcpy(ptr2 + n, ptr2, n);
+            n *= 2;
+        }
+        memcpy(ptr2 + n, ptr2, len-n);
+    }
+    ptr2[RSTRING_LEN(str2)] = '\0';
     OBJ_INFECT(str2, str);
 
     return str2;