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5f42a240ba
1. teach SimplifySetCC that '(srl (ctlz x), 5) == 0' is really x != 0.
2. Teach visitSELECT_CC to use SimplifySetCC instead of calling it and
ignoring the result. This allows us to compile:
bool %test(ulong %x) {
%tmp = setlt ulong %x, 4294967296
ret bool %tmp
}
to:
_test:
cntlzw r2, r3
cmplwi cr0, r3, 1
srwi r2, r2, 5
li r3, 0
beq cr0, LBB1_2 ;
LBB1_1: ;
mr r3, r2
LBB1_2: ;
blr
instead of:
_test:
addi r2, r3, -1
cntlzw r2, r2
cntlzw r3, r3
srwi r2, r2, 5
cmplwi cr0, r2, 0
srwi r2, r3, 5
li r3, 0
bne cr0, LBB1_2 ;
LBB1_1: ;
mr r3, r2
LBB1_2: ;
blr
This isn't wonderful, but it's an improvement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30513 91177308-0d34-0410-b5e6-96231b3b80d8
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