From 45d19fb470616851a1e2b15f247739c60902445c Mon Sep 17 00:00:00 2001 From: Jay Foad Date: Wed, 19 Jun 2019 10:28:48 +0000 Subject: [PATCH] [ConstantFolding] Fix assertion failure on non-power-of-two vector load. Summary: The test case does an (out of bounds) load from a global constant with type <3 x float>. InstSimplify tried to turn this into an integer load of the whole alloc size of the vector, which is 128 bits due to alignment padding, and then bitcast this to <3 x vector> which failed an assertion due to the type size mismatch. The fix is to do an integer load of the normal size of the vector, with no alignment padding. Reviewers: tpr, arsenm, majnemer, dstuttard Reviewed By: arsenm Subscribers: hfinkel, wdng, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D63375 llvm-svn: 363784 --- llvm/lib/Analysis/ConstantFolding.cpp | 2 +- llvm/test/Transforms/InstSimplify/load.ll | 10 ++++++++++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp index 85390e377084..4657b855d098 100644 --- a/llvm/lib/Analysis/ConstantFolding.cpp +++ b/llvm/lib/Analysis/ConstantFolding.cpp @@ -515,7 +515,7 @@ Constant *FoldReinterpretLoadFromConstPtr(Constant *C, Type *LoadTy, MapTy = Type::getInt64Ty(C->getContext()); else if (LoadTy->isVectorTy()) { MapTy = PointerType::getIntNTy(C->getContext(), - DL.getTypeAllocSizeInBits(LoadTy)); + DL.getTypeSizeInBits(LoadTy)); } else return nullptr; diff --git a/llvm/test/Transforms/InstSimplify/load.ll b/llvm/test/Transforms/InstSimplify/load.ll index 8b2b5a17660f..0c2d827acbcc 100644 --- a/llvm/test/Transforms/InstSimplify/load.ll +++ b/llvm/test/Transforms/InstSimplify/load.ll @@ -28,3 +28,13 @@ define <8 x i32> @partial_load() { %load = load <8 x i32>, <8 x i32>* bitcast (i32* getelementptr ([8 x i32], [8 x i32]* @GV, i64 0, i64 -1) to <8 x i32>*) ret <8 x i32> %load } + +@constvec = internal constant <3 x float> + +; This does an out of bounds load from the global constant +define <3 x float> @load_vec3() { +; CHECK-LABEL: @load_vec3( +; CHECK-NEXT: ret <3 x float> undef + %1 = load <3 x float>, <3 x float>* getelementptr inbounds (<3 x float>, <3 x float>* @constvec, i64 1) + ret <3 x float> %1 +}