git: 397a8ba05313 - main - Apply fix for LLVM PR51957 (Miscompilation in Botan's SHA3)
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Date: Sat, 13 Nov 2021 20:57:14 UTC
The branch main has been updated by dim: URL: https://cgit.FreeBSD.org/src/commit/?id=397a8ba05313cc3815d219c9d1b2de1372fcb561 commit 397a8ba05313cc3815d219c9d1b2de1372fcb561 Author: Dimitry Andric <dim@FreeBSD.org> AuthorDate: 2021-11-10 18:38:23 +0000 Commit: Dimitry Andric <dim@FreeBSD.org> CommitDate: 2021-11-13 20:52:25 +0000 Apply fix for LLVM PR51957 (Miscompilation in Botan's SHA3) Merge commit e27a6db5298f from llvm git (by Jameson Nash): Bad SLPVectorization shufflevector replacement, resulting in write to wrong memory location We see that it might otherwise do: %10 = getelementptr {}**, <2 x {}***> %9, <2 x i32> <i32 10, i32 4> %11 = bitcast <2 x {}***> %10 to <2 x i64*> ... %27 = extractelement <2 x i64*> %11, i32 0 %28 = bitcast i64* %27 to <2 x i64>* store <2 x i64> %22, <2 x i64>* %28, align 4, !tbaa !2 Which is an out-of-bounds store (the extractelement got offset 10 instead of offset 4 as intended). With the fix, we correctly generate extractelement for i32 1 and generate correct code. Differential Revision: https://reviews.llvm.org/D106613 --- .../lib/Transforms/Vectorize/SLPVectorizer.cpp | 25 ++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/contrib/llvm-project/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/contrib/llvm-project/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp index cc3f5c7d4b48..1d06bc7d79a7 100644 --- a/contrib/llvm-project/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp +++ b/contrib/llvm-project/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp @@ -5430,8 +5430,11 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) { // The pointer operand uses an in-tree scalar so we add the new BitCast // to ExternalUses list to make sure that an extract will be generated // in the future. - if (getTreeEntry(PO)) - ExternalUses.emplace_back(PO, cast<User>(VecPtr), 0); + if (TreeEntry *Entry = getTreeEntry(PO)) { + // Find which lane we need to extract. + unsigned FoundLane = Entry->findLaneForValue(PO); + ExternalUses.emplace_back(PO, cast<User>(VecPtr), FoundLane); + } NewLI = Builder.CreateAlignedLoad(VecTy, VecPtr, LI->getAlign()); } else { @@ -5474,8 +5477,12 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) { // The pointer operand uses an in-tree scalar, so add the new BitCast to // ExternalUses to make sure that an extract will be generated in the // future. - if (getTreeEntry(ScalarPtr)) - ExternalUses.push_back(ExternalUser(ScalarPtr, cast<User>(VecPtr), 0)); + if (TreeEntry *Entry = getTreeEntry(ScalarPtr)) { + // Find which lane we need to extract. + unsigned FoundLane = Entry->findLaneForValue(ScalarPtr); + ExternalUses.push_back( + ExternalUser(ScalarPtr, cast<User>(VecPtr), FoundLane)); + } Value *V = propagateMetadata(ST, E->Scalars); @@ -5577,8 +5584,14 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) { // The scalar argument uses an in-tree scalar so we add the new vectorized // call to ExternalUses list to make sure that an extract will be // generated in the future. - if (ScalarArg && getTreeEntry(ScalarArg)) - ExternalUses.push_back(ExternalUser(ScalarArg, cast<User>(V), 0)); + if (ScalarArg) { + if (TreeEntry *Entry = getTreeEntry(ScalarArg)) { + // Find which lane we need to extract. + unsigned FoundLane = Entry->findLaneForValue(ScalarArg); + ExternalUses.push_back( + ExternalUser(ScalarArg, cast<User>(V), FoundLane)); + } + } propagateIRFlags(V, E->Scalars, VL0); ShuffleBuilder.addMask(E->ReuseShuffleIndices);