now that addc/adde are gone, "ADDC" in the X86 backend uses EFLAGS results,
the same as setcc. Optimize ADDC(0,0,FLAGS) -> SET_CARRY(FLAGS). This is
a step towards finishing off PR5443. In the testcase in that bug we now get:
movq %rdi, %rax
addq %rsi, %rax
sbbq %rcx, %rcx
testb $1, %cl
setne %dl
ret
instead of:
movq %rdi, %rax
addq %rsi, %rax
movl $0, %ecx
adcq $0, %rcx
testq %rcx, %rcx
setne %dl
ret
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122219
91177308-0d34-0410-b5e6-
96231b3b80d8