Take advantage of undefined behavior if the source program tries to GEP

beyond the end of an alloca to make FastDSE faster and more aggressive.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39945 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2007-07-16 23:34:39 +00:00
parent 162c518286
commit ce17b1c1f8

View File

@ -61,17 +61,10 @@ namespace {
// See through pointer-to-pointer bitcasts
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;
}
if (BitCastInst* C = dyn_cast<BitCastInst>(v))
v = C->getOperand(0);
else if (GetElementPtrInst* G = dyn_cast<GetElementPtrInst>(v))
v = G->getOperand(0);
}
// getAnalysisUsage - We require post dominance frontiers (aka Control