[Bug target/41868] cell microcode instruction (addic.) is generated for a trivial loop with -O2 optimizations, hurting performance badly

[pinskia at gcc dot gnu dot org]

------- Comment #5 from pinskia at gcc dot gnu dot org  2009-11-02 17:08 -------
In fact doing the following diff to the -Os assembly:
--- t5.Os.s     2009-11-02 23:18:52.000000000 +0900
+++ t5.Os.dot.s 2009-11-02 23:20:19.000000000 +0900
@@ -29,9 +29,9 @@ x:
 .L4:
        bl y
 .L3:
-       cmpwi 7,31,0
-       addi 31,31,-1
-       bne 7,.L4
+#      cmpwi 7,31,0
+       addic. 31,31,-1
+       bne .L4
        addi 11,1,16
        b _restgpr_31_x
        .size   x,.-x

produces the same result as -Os on the trunk.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41868