Add some comments clarifying that the GEP analysis for vector GEPs is
deeply suspicious and likely to go away eventually. Also fix a bogus
comment about one of the checks in the vector GEP analysis. Based on
review from Duncan.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163894 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SROA.cpp b/lib/Transforms/Scalar/SROA.cpp
index acfa87a..97c28d4 100644
--- a/lib/Transforms/Scalar/SROA.cpp
+++ b/lib/Transforms/Scalar/SROA.cpp
@@ -1300,10 +1300,13 @@
if (Ty->isPointerTy())
return 0;
+ // We try to analyze GEPs over vectors here, but note that these GEPs are
+ // extremely poorly defined currently. The long-term goal is to remove GEPing
+ // over a vector from the IR completely.
if (VectorType *VecTy = dyn_cast<VectorType>(Ty)) {
unsigned ElementSizeInBits = VecTy->getScalarSizeInBits();
if (ElementSizeInBits % 8)
- return 0; // GEPs over multiple of 8 size vector elements are invalid.
+ return 0; // GEPs over non-multiple of 8 size vector elements are invalid.
APInt ElementSize(Offset.getBitWidth(), ElementSizeInBits / 8);
APInt NumSkippedElements = Offset.udiv(ElementSize);
if (NumSkippedElements.ugt(VecTy->getNumElements()))