[Qemu-devel] [PATCH target-arm] Don' use T[x] in helper

[Torbjörn Andersson]

Hi all!

I hit a strange issue with add_cc, can't really explain how it appeared but
it did. The patch below solved my problem.

Can someone make a qualified guess why? I'm compling with gcc 4.

However, T0 and T1 in a helper should not be used, because it creates a
unnecessary dependency between translate.c and op_helper.c. Am I correct?

Further, if we cannot trust T0 and T1 in a helper, what about the global
env-variable?

/Best regards Torbjörn Andersson

Index: op_helper.c
===================================================================
--- op_helper.c (revision 6883)
+++ op_helper.c (working copy)
@@ -307,7 +307,7 @@
 uint32_t HELPER (add_cc)(uint32_t a, uint32_t b)
 {
     uint32_t result;
-    result = T0 + T1;
+    result = a + b;
     env->NF = env->ZF = result;
     env->CF = result < a;
     env->VF = (a ^ b ^ -1) & (a ^ result);