Enhance GVN to do more precise alias queries for non-local memory
references. For example, this allows gvn to eliminate the load in
this example:
void foo(int n, int* p, int *q) {
p[0] = 0;
p[1] = 1;
if (n) {
*q = p[0];
}
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118714 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index a2fcca5..e506d0e 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -1351,8 +1351,10 @@
SmallVectorImpl<Instruction*> &toErase) {
// Find the non-local dependencies of the load.
SmallVector<NonLocalDepResult, 64> Deps;
- MD->getNonLocalPointerDependency(LI->getPointerOperand(), true,
- LI->getParent(),
+ AliasAnalysis::Location Loc(LI->getPointerOperand(),
+ VN.getAliasAnalysis()->getTypeStoreSize(LI->getType()),
+ LI->getMetadata(LLVMContext::MD_tbaa));
+ MD->getNonLocalPointerDependency(Loc, true, LI->getParent(),
Deps);
//DEBUG(dbgs() << "INVESTIGATING NONLOCAL LOAD: "
// << Deps.size() << *LI << '\n');