patch for CRuby. make Array#collect faster.

collect.patch

Index: array.c
===================================================================
--- array.c (revision 35267)
+++ array.c (working copy)
@@ -2255,12 +2255,19 @@ static VALUE
 rb_ary_collect(VALUE ary)
 {
     long i;
-    VALUE collect;
+    VALUE collect, v;
 
     RETURN_ENUMERATOR(ary, 0, 0);
     collect = rb_ary_new2(RARRAY_LEN(ary));
+    ARY_SET_LEN(collect, RARRAY_LEN(ary));
+    rb_mem_clear(RARRAY_PTR(collect), RARRAY_LEN(ary));
     for (i = 0; i < RARRAY_LEN(ary); i++) {
-	rb_ary_push(collect, rb_yield(RARRAY_PTR(ary)[i]));
+	v = rb_yield(RARRAY_PTR(ary)[i]);
+	if (RARRAY_LEN(collect) > i) {
+	    RARRAY_PTR(collect)[i] = v;
+        } else {
+	    rb_ary_push(collect, v);
+        }
     }
     return collect;
 }
@@ -2288,11 +2295,22 @@ static VALUE
 rb_ary_collect_bang(VALUE ary)
 {
     long i;
+    VALUE v;
 
     RETURN_ENUMERATOR(ary, 0, 0);
     rb_ary_modify(ary);
-    for (i = 0; i < RARRAY_LEN(ary); i++) {
-	rb_ary_store(ary, i, rb_yield(RARRAY_PTR(ary)[i]));
+    if (RARRAY_LEN(ary) == 0) {
+	return ary;
+    }
+    i = 0;
+    for (;;) {
+	v = rb_yield(RARRAY_PTR(ary)[i]);
+	if (RARRAY_LEN(ary) - 1 > i) {
+	    RARRAY_PTR(ary)[i++] = v;
+	} else {
+	    rb_ary_store(ary, i, v);
+	    break;
+	}
     }
     return ary;
 }