[ConstraintElim] Preserve analyses when IR is unchanged. #128588
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@llvm/pr-subscribers-llvm-transforms Author: Andreas Jonson (andjo403) ChangesNoticed that all Analys passes was not preserved for unchanged IR when the test was containing assumes.
Not sure how to/if possible to add a test for this. Full diff: https://github.com/llvm/llvm-project/pull/128588.diff 1 Files Affected:
diff --git a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
index 79f6858463d7e..267eb319a5616 100644
--- a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
@@ -1435,8 +1435,9 @@ static bool checkAndReplaceCondition(
generateReproducer(Cmp, ReproducerModule, ReproducerCondStack, Info, DT);
Constant *ConstantC = ConstantInt::getBool(
CmpInst::makeCmpResultType(Cmp->getType()), IsTrue);
- Cmp->replaceUsesWithIf(ConstantC, [&DT, NumIn, NumOut,
- ContextInst](Use &U) {
+ bool Changed = false;
+ Cmp->replaceUsesWithIf(ConstantC, [&DT, NumIn, NumOut, ContextInst,
+ &Changed](Use &U) {
auto *UserI = getContextInstForUse(U);
auto *DTN = DT.getNode(UserI->getParent());
if (!DTN || DTN->getDFSNumIn() < NumIn || DTN->getDFSNumOut() > NumOut)
@@ -1448,12 +1449,14 @@ static bool checkAndReplaceCondition(
// Conditions in an assume trivially simplify to true. Skip uses
// in assume calls to not destroy the available information.
auto *II = dyn_cast<IntrinsicInst>(U.getUser());
- return !II || II->getIntrinsicID() != Intrinsic::assume;
+ bool ShouldReplace = !II || II->getIntrinsicID() != Intrinsic::assume;
+ Changed |= ShouldReplace;
+ return ShouldReplace;
});
NumCondsRemoved++;
if (Cmp->use_empty())
ToRemove.push_back(Cmp);
- return true;
+ return Changed;
};
if (auto ImpliedCondition =
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Then we should use an analysis that doesn't get preserved even when changes are made. |
andjo403
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test added |
Noticed that all Analys passes was not preserved for unchanged IR when the test was containing assumes.
PreservedAnalyses::all()is not called for E.g. https://github.com/andjo403/llvm-project/blob/e24bb833b1af521fc2aec997a8b89de795b34449/llvm/test/Transforms/ConstraintElimination/mul.ll#L283-L301Not sure how to/if possible to add a test for this.