On 09/02/16 15:34, Claudiu Zissulescu wrote:
Most of the cases checking only the CC user may be sufficient. However, there
are cases (only one which I found), where the CC user has a different mode than
of the CC setter. This is happening when running gcc.dg/pr56424.c test. Here,
the C_FPU mode cstore is simplified by the following steps losing the CC_FPU
mode:
In the expand:
18: cc:CC_FPU=cmp(r159:DF,r162:DF)
19: r163:SI=cc:CC_FPU<0
20: r161:QI=r163:SI#0
21: r153:SI=zero_extend(r161:QI)
22: cc:CC_ZN=cmp(r153:SI,0)
23: pc={(cc:CC_ZN!=0)?L28:pc}
Then after combine we get this:
18: cc:CC_FPU=cmp(r2:DF,r4:DF)
REG_DEAD r4:DF
REG_DEAD r2:DF
23: pc={(cc:CC_ZN<0)?L28:pc}
REG_DEAD cc:CC_ZN
REG_BR_PROB 6102
That sound like a bug. Have you looked more closely what's going on?
