From 8ed1ed8dfd2cf9215446c637a416a5a31f96051e Mon Sep 17 00:00:00 2001 From: Chandler Carruth Date: Fri, 14 Sep 2012 10:30:40 +0000 Subject: [PATCH 1/1] 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 --- lib/Transforms/Scalar/SROA.cpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Scalar/SROA.cpp b/lib/Transforms/Scalar/SROA.cpp index acfa87a32eb..97c28d442ad 100644 --- a/lib/Transforms/Scalar/SROA.cpp +++ b/lib/Transforms/Scalar/SROA.cpp @@ -1300,10 +1300,13 @@ static Value *getNaturalGEPRecursively(IRBuilder<> &IRB, const TargetData &TD, 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(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())) -- 2.34.1