runtime: replace XOR AX, AX with MOV $0, AX

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5985048

diff --git a/src/pkg/runtime/asm_386.s b/src/pkg/runtime/asm_386.s
index 124fd2766b916b68bb868fa798145259be3ef05d..3ab34d34cbe1318eb6a50e790fa458102fc0ba70 100644 (file)
--- a/src/pkg/runtime/asm_386.s
+++ b/src/pkg/runtime/asm_386.s
@@ -323,7 +323,7 @@ TEXT runtime·cas64(SB), 7, $0
 cas64_fail:
        MOVL    AX, 0(SI)
        MOVL    DX, 4(SI)
-       XORL    AX, AX
+       MOVL    $0, AX
        RET
 
 // bool casp(void **p, void *old, void *new)