[llvm] [VPlan] Cover additional GEP-like recipes in m_GetElementPtr (PR #158019)
Ramkumar Ramachandra via llvm-commits
llvm-commits at lists.llvm.org
Mon Sep 15 03:28:24 PDT 2025
https://github.com/artagnon updated https://github.com/llvm/llvm-project/pull/158019
>From cbf36e236ea917e5635f3de0c22a3c4ac62837be Mon Sep 17 00:00:00 2001
From: Ramkumar Ramachandra <ramkumar.ramachandra at codasip.com>
Date: Thu, 11 Sep 2025 10:00:47 +0100
Subject: [PATCH 1/3] [VPlan/PatternMatch] Fix m_GetElementPtr (NFC)
The m_GetElementPtr matcher is incorrect and incomplete. Fix it to match
all possible GEPs to avoid misleading users. It currently just has one
use, and the change is non-functional for that use.
---
llvm/lib/Transforms/Vectorize/VPlan.h | 3 +++
.../Transforms/Vectorize/VPlanPatternMatch.h | 26 +++++++++++++------
2 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/VPlan.h b/llvm/lib/Transforms/Vectorize/VPlan.h
index 53291a931530f..db0f6dea254e8 100644
--- a/llvm/lib/Transforms/Vectorize/VPlan.h
+++ b/llvm/lib/Transforms/Vectorize/VPlan.h
@@ -1799,6 +1799,9 @@ class LLVM_ABI_FOR_TEST VPWidenGEPRecipe : public VPRecipeWithIRFlags {
VP_CLASSOF_IMPL(VPDef::VPWidenGEPSC)
+ /// This recipe generates a GEP instruction.
+ unsigned getOpcode() const { return Instruction::GetElementPtr; }
+
/// Generate the gep nodes.
void execute(VPTransformState &State) override;
diff --git a/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h b/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
index 109156c1469c5..14ade616b9831 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
+++ b/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
@@ -252,10 +252,10 @@ struct Recipe_match {
static bool matchRecipeAndOpcode(const VPRecipeBase *R) {
auto *DefR = dyn_cast<RecipeTy>(R);
// Check for recipes that do not have opcodes.
- if constexpr (std::is_same<RecipeTy, VPScalarIVStepsRecipe>::value ||
- std::is_same<RecipeTy, VPCanonicalIVPHIRecipe>::value ||
- std::is_same<RecipeTy, VPDerivedIVRecipe>::value ||
- std::is_same<RecipeTy, VPWidenGEPRecipe>::value)
+ if constexpr (std::is_same_v<RecipeTy, VPScalarIVStepsRecipe> ||
+ std::is_same_v<RecipeTy, VPCanonicalIVPHIRecipe> ||
+ std::is_same_v<RecipeTy, VPDerivedIVRecipe> ||
+ std::is_same_v<RecipeTy, VPVectorPointerRecipe>)
return DefR;
else
return DefR && DefR->getOpcode() == Opcode;
@@ -524,15 +524,25 @@ m_SpecificCmp(CmpPredicate MatchPred, const Op0_t &Op0, const Op1_t &Op1) {
}
template <typename Op0_t, typename Op1_t>
-using GEPLikeRecipe_match =
+using GEPLikeRecipe_match = match_combine_or<
Recipe_match<std::tuple<Op0_t, Op1_t>, Instruction::GetElementPtr,
- /*Commutative*/ false, VPWidenRecipe, VPReplicateRecipe,
- VPWidenGEPRecipe, VPInstruction>;
+ /*Commutative*/ false, VPReplicateRecipe, VPWidenGEPRecipe,
+ VPVectorPointerRecipe>,
+ match_combine_or<
+ VPInstruction_match<VPInstruction::PtrAdd, Op0_t, Op1_t>,
+ VPInstruction_match<VPInstruction::WidePtrAdd, Op0_t, Op1_t>>>;
template <typename Op0_t, typename Op1_t>
inline GEPLikeRecipe_match<Op0_t, Op1_t> m_GetElementPtr(const Op0_t &Op0,
const Op1_t &Op1) {
- return GEPLikeRecipe_match<Op0_t, Op1_t>(Op0, Op1);
+ return m_CombineOr(
+ Recipe_match<std::tuple<Op0_t, Op1_t>, Instruction::GetElementPtr,
+ /*Commutative*/ false, VPReplicateRecipe, VPWidenGEPRecipe,
+ VPVectorPointerRecipe>(Op0, Op1),
+ m_CombineOr(
+ VPInstruction_match<VPInstruction::PtrAdd, Op0_t, Op1_t>(Op0, Op1),
+ VPInstruction_match<VPInstruction::WidePtrAdd, Op0_t, Op1_t>(Op0,
+ Op1)));
}
template <typename Op0_t, typename Op1_t, typename Op2_t>
>From 440600d80ce84280ea1e1fd88fd6433d70992e5b Mon Sep 17 00:00:00 2001
From: Ramkumar Ramachandra <ramkumar.ramachandra at codasip.com>
Date: Thu, 11 Sep 2025 10:17:39 +0100
Subject: [PATCH 2/3] [VPlan/PatternMatch] Strip VectorPointerRecipe
---
llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h b/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
index 14ade616b9831..b3735786585cf 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
+++ b/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
@@ -254,8 +254,7 @@ struct Recipe_match {
// Check for recipes that do not have opcodes.
if constexpr (std::is_same_v<RecipeTy, VPScalarIVStepsRecipe> ||
std::is_same_v<RecipeTy, VPCanonicalIVPHIRecipe> ||
- std::is_same_v<RecipeTy, VPDerivedIVRecipe> ||
- std::is_same_v<RecipeTy, VPVectorPointerRecipe>)
+ std::is_same_v<RecipeTy, VPDerivedIVRecipe>)
return DefR;
else
return DefR && DefR->getOpcode() == Opcode;
@@ -526,8 +525,7 @@ m_SpecificCmp(CmpPredicate MatchPred, const Op0_t &Op0, const Op1_t &Op1) {
template <typename Op0_t, typename Op1_t>
using GEPLikeRecipe_match = match_combine_or<
Recipe_match<std::tuple<Op0_t, Op1_t>, Instruction::GetElementPtr,
- /*Commutative*/ false, VPReplicateRecipe, VPWidenGEPRecipe,
- VPVectorPointerRecipe>,
+ /*Commutative*/ false, VPReplicateRecipe, VPWidenGEPRecipe>,
match_combine_or<
VPInstruction_match<VPInstruction::PtrAdd, Op0_t, Op1_t>,
VPInstruction_match<VPInstruction::WidePtrAdd, Op0_t, Op1_t>>>;
@@ -537,8 +535,8 @@ inline GEPLikeRecipe_match<Op0_t, Op1_t> m_GetElementPtr(const Op0_t &Op0,
const Op1_t &Op1) {
return m_CombineOr(
Recipe_match<std::tuple<Op0_t, Op1_t>, Instruction::GetElementPtr,
- /*Commutative*/ false, VPReplicateRecipe, VPWidenGEPRecipe,
- VPVectorPointerRecipe>(Op0, Op1),
+ /*Commutative*/ false, VPReplicateRecipe, VPWidenGEPRecipe>(
+ Op0, Op1),
m_CombineOr(
VPInstruction_match<VPInstruction::PtrAdd, Op0_t, Op1_t>(Op0, Op1),
VPInstruction_match<VPInstruction::WidePtrAdd, Op0_t, Op1_t>(Op0,
>From e8a9716fb9514b6945f1b6728cb6d6d8f5b0bd91 Mon Sep 17 00:00:00 2001
From: Ramkumar Ramachandra <ramkumar.ramachandra at codasip.com>
Date: Mon, 15 Sep 2025 11:24:16 +0100
Subject: [PATCH 3/3] [VPlan] Add unit-test
---
.../Vectorize/VPlanPatternMatchTest.cpp | 24 +++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/llvm/unittests/Transforms/Vectorize/VPlanPatternMatchTest.cpp b/llvm/unittests/Transforms/Vectorize/VPlanPatternMatchTest.cpp
index e38b4fad80b0e..582094bed3ef7 100644
--- a/llvm/unittests/Transforms/Vectorize/VPlanPatternMatchTest.cpp
+++ b/llvm/unittests/Transforms/Vectorize/VPlanPatternMatchTest.cpp
@@ -51,5 +51,29 @@ TEST_F(VPPatternMatchTest, ScalarIVSteps) {
m_SpecificInt(2), m_Specific(VF))));
}
+TEST_F(VPPatternMatchTest, GetElementPtr) {
+ VPlan &Plan = getPlan();
+ VPBasicBlock *VPBB = Plan.createVPBasicBlock("entry");
+ VPBuilder Builder(VPBB);
+
+ IntegerType *I64Ty = IntegerType::get(C, 64);
+ VPValue *One = Plan.getOrAddLiveIn(ConstantInt::get(I64Ty, 1));
+ VPValue *Two = Plan.getOrAddLiveIn(ConstantInt::get(I64Ty, 2));
+ VPValue *Ptr =
+ Plan.getOrAddLiveIn(Constant::getNullValue(PointerType::get(C, 0)));
+
+ VPInstruction *PtrAdd = Builder.createPtrAdd(Ptr, One);
+ VPInstruction *WidePtrAdd = Builder.createWidePtrAdd(Ptr, Two);
+
+ using namespace VPlanPatternMatch;
+ ASSERT_TRUE(
+ match(PtrAdd, m_GetElementPtr(m_Specific(Ptr), m_SpecificInt(1))));
+ ASSERT_FALSE(
+ match(PtrAdd, m_GetElementPtr(m_Specific(Ptr), m_SpecificInt(2))));
+ ASSERT_TRUE(
+ match(WidePtrAdd, m_GetElementPtr(m_Specific(Ptr), m_SpecificInt(2))));
+ ASSERT_FALSE(
+ match(WidePtrAdd, m_GetElementPtr(m_Specific(Ptr), m_SpecificInt(1))));
+}
} // namespace
} // namespace llvm
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