[llvm] [VPlan] Remove verifyEVLRecipe (PR #182798)
Luke Lau via llvm-commits
llvm-commits at lists.llvm.org
Sun Feb 22 20:40:32 PST 2026
https://github.com/lukel97 created https://github.com/llvm/llvm-project/pull/182798
In #182254 we want to start aborting compilation when the verifier fails between passes, but currently we run into various EVL related failures.
The EVL is used in quite a few more places than when the verification was originally added, all of which need to be handled by the verifier. I think this is also exacerbated by the fact that many recipes nowadays are converted to concrete recipes later in the pipeline which duplicates the number of patterns we need to match.
The EVL transform itself has also changed much since its original implementation, i.e. non-trapping recipes don't use EVL (#127180) and VP recipes are generated via pattern matching instead of unconditionally (#155394), so I'm not sure if the verification is as relevant today.
Rather than try to add more patterns this PR removes the verification to reduce the maintainence cost. Split off from #182254
>From 18cb87aa5846c32ddd48b79981f475fe81d29574 Mon Sep 17 00:00:00 2001
From: Luke Lau <luke at igalia.com>
Date: Mon, 23 Feb 2026 12:38:16 +0800
Subject: [PATCH] [VPlan] Remove verifyEVLRecipe
In #182254 we want to start aborting compilation when the verifier fails between passes, but currently we run into various EVL related failures.
The EVL is used in quite a few more places than when the verification was originally added, all of which need to be handled by the verifier. I think this is also exacerbated by the fact that many recipes nowadays are converted to concrete recipes later in the pipeline which duplicates the number of patterns we need to match.
The EVL transform itself has also changed much since its original implementation, i.e. non-trapping recipes don't use EVL (#127180) and VP recipes are generated via pattern matching instead of unconditionally (#155394), so I'm not sure if the verification is as relevant today.
Rather than try to add more patterns this PR removes the verification to reduce the maintainence cost. Split off from #182254
---
.../Transforms/Vectorize/VPlanVerifier.cpp | 113 ------------------
1 file changed, 113 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp b/llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp
index e4b334c3eba49..d634ade306c19 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp
@@ -40,11 +40,6 @@ class VPlanVerifier {
// VPHeaderPHIRecipes.
bool verifyPhiRecipes(const VPBasicBlock *VPBB);
- /// Verify that \p EVL is used correctly. The user must be either in
- /// EVL-based recipes as a last operand or VPInstruction::Add which is
- /// incoming value into EVL's recipe.
- bool verifyEVLRecipe(const VPInstruction &EVL) const;
-
/// Verify that \p LastActiveLane's operand is guaranteed to be a prefix-mask.
bool verifyLastActiveLaneRecipe(const VPInstruction &LastActiveLane) const;
@@ -146,108 +141,6 @@ bool VPlanVerifier::verifyPhiRecipes(const VPBasicBlock *VPBB) {
return true;
}
-bool VPlanVerifier::verifyEVLRecipe(const VPInstruction &EVL) const {
- if (EVL.getOpcode() != VPInstruction::ExplicitVectorLength) {
- errs() << "verifyEVLRecipe should only be called on "
- "VPInstruction::ExplicitVectorLength\n";
- return false;
- }
- auto VerifyEVLUse = [&](const VPRecipeBase &R,
- const unsigned ExpectedIdx) -> bool {
- SmallVector<const VPValue *> Ops(R.operands());
- unsigned UseCount = count(Ops, &EVL);
- if (UseCount != 1 || Ops[ExpectedIdx] != &EVL) {
- errs() << "EVL is used as non-last operand in EVL-based recipe\n";
- return false;
- }
- return true;
- };
- auto VerifyEVLUseInVecEndPtr = [&EVL](auto &VEPRs) {
- if (all_of(VEPRs, [&EVL](VPUser *U) {
- auto *VEPR = cast<VPVectorEndPointerRecipe>(U);
- return match(VEPR->getOffset(),
- m_c_Mul(m_SpecificSInt(VEPR->getStride()),
- m_Sub(m_Specific(&EVL), m_One())));
- }))
- return true;
- errs() << "Expected VectorEndPointer with EVL operand\n";
- return false;
- };
- return all_of(EVL.users(), [&](VPUser *U) {
- return TypeSwitch<const VPUser *, bool>(U)
- .Case([&](const VPWidenIntrinsicRecipe *S) {
- return VerifyEVLUse(*S, S->getNumOperands() - 1);
- })
- .Case<VPWidenStoreEVLRecipe, VPReductionEVLRecipe,
- VPWidenIntOrFpInductionRecipe, VPWidenPointerInductionRecipe>(
- [&](const VPRecipeBase *S) { return VerifyEVLUse(*S, 2); })
- .Case([&](const VPScalarIVStepsRecipe *R) {
- if (R->getNumOperands() != 3) {
- errs() << "Unrolling with EVL tail folding not yet supported\n";
- return false;
- }
- return VerifyEVLUse(*R, 2);
- })
- .Case<VPWidenLoadEVLRecipe, VPVectorEndPointerRecipe,
- VPInterleaveEVLRecipe>(
- [&](const VPRecipeBase *R) { return VerifyEVLUse(*R, 1); })
- .Case(
- [&](const VPInstructionWithType *S) { return VerifyEVLUse(*S, 0); })
- .Case([&](const VPInstruction *I) {
- if (I->getOpcode() == Instruction::PHI ||
- I->getOpcode() == Instruction::ICmp)
- return VerifyEVLUse(*I, 1);
- if (I->getOpcode() == Instruction::Sub) {
- // If Sub has a single user that's a SingleDefRecipe (which is
- // expected to be a Mul), filter its users, in turn, to get
- // VectorEndPointerRecipes, and verify that all the offsets match
- // (EVL - 1) * Stride.
- if (auto *Def = dyn_cast_if_present<VPSingleDefRecipe>(
- I->getSingleUser())) {
- auto VEPRs = make_filter_range(Def->users(),
- IsaPred<VPVectorEndPointerRecipe>);
- if (!VEPRs.empty())
- return VerifyEVLUseInVecEndPtr(VEPRs);
- }
- return VerifyEVLUse(*I, 1);
- }
- switch (I->getOpcode()) {
- case Instruction::Add:
- break;
- case Instruction::UIToFP:
- case Instruction::Trunc:
- case Instruction::ZExt:
- case Instruction::Mul:
- case Instruction::Shl:
- case Instruction::FMul:
- case VPInstruction::Broadcast:
- case VPInstruction::PtrAdd:
- // Opcodes above can only use EVL after wide inductions have been
- // expanded.
- if (!VerifyLate) {
- errs() << "EVL used by unexpected VPInstruction\n";
- return false;
- }
- break;
- default:
- errs() << "EVL used by unexpected VPInstruction\n";
- return false;
- }
- if (!VerifyLate &&
- !isa<VPCurrentIterationPHIRecipe>(*I->users().begin())) {
- errs() << "Result of VPInstruction::Add with EVL operand is "
- "not used by VPCurrentIterationPHIRecipe\n";
- return false;
- }
- return true;
- })
- .Default([&](const VPUser *U) {
- errs() << "EVL has unexpected user\n";
- return false;
- });
- });
-}
-
bool VPlanVerifier::verifyLastActiveLaneRecipe(
const VPInstruction &LastActiveLane) const {
assert(LastActiveLane.getOpcode() == VPInstruction::LastActiveLane &&
@@ -372,12 +265,6 @@ bool VPlanVerifier::verifyVPBasicBlock(const VPBasicBlock *VPBB) {
}
if (const auto *VPI = dyn_cast<VPInstruction>(&R)) {
switch (VPI->getOpcode()) {
- case VPInstruction::ExplicitVectorLength:
- if (!verifyEVLRecipe(*VPI)) {
- errs() << "EVL VPValue is not used correctly\n";
- return false;
- }
- break;
case VPInstruction::LastActiveLane:
if (!verifyLastActiveLaneRecipe(*VPI))
return false;
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