Handle GEPs with all-zero indices in the same way we handle pointer-pointer bitcasts. Also, fix a potentia infinite loop.

This brings FastDSE to parity with old DSE on 175.vpr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39839 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2007-07-13 22:50:48 +00:00
parent fba36b8cba
commit a08971559d

View File

@ -60,9 +60,18 @@ namespace {
assert(isa<PointerType>(v->getType()) && "Translating a non-pointer type?");
// See through pointer-to-pointer bitcasts
while (BitCastInst* C = dyn_cast<BitCastInst>(v))
if (isa<PointerType>(C->getSrcTy()))
v = C->getOperand(0);
while (isa<BitCastInst>(v) || isa<GetElementPtrInst>(v))
if (BitCastInst* C = dyn_cast<BitCastInst>(v)) {
if (isa<PointerType>(C->getSrcTy()))
v = C->getOperand(0);
else
break;
} else if (GetElementPtrInst* G = dyn_cast<GetElementPtrInst>(v)) {
if (G->hasAllZeroIndices())
v = G->getOperand(0);
else
break;
}
}
// getAnalysisUsage - We require post dominance frontiers (aka Control