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Apply fix for LLVM PR51957 (Miscompilation in Botan's SHA3)

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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
This commit is contained in:
Dimitry Andric 2021-11-10 19:38:23 +01:00
parent a18c6161ef
commit 397a8ba053
1 changed files with 19 additions and 6 deletions
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25
contrib/llvm-project/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
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@ -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);