[llvm] [VPlan] Ignore incoming values with constant false mask. (PR #89384)
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 22 06:07:56 PDT 2024
https://github.com/fhahn updated https://github.com/llvm/llvm-project/pull/89384
>From fe47c389e1447c5d284da7fc3905c60dbe6ac94d Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Fri, 19 Apr 2024 14:14:05 +0100
Subject: [PATCH 1/2] [VPlan] Ignore incoming values with constant false mask.
Ignore incoming values with constant false masks when trying to simplify
VPBlendRecipes.
As a follow-on optimization, we should also be able to drop all incoming
values with false masks by creating a new VPBlendRecipe with those
operands dropped.
---
llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h | 11 +++++++----
llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp | 5 +++--
.../unused-blend-mask-for-first-operand.ll | 6 +-----
3 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h b/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
index ae7717eb7cc97f..cbd53a2307a105 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
+++ b/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
@@ -52,7 +52,7 @@ template <typename Class> struct bind_ty {
/// Match a specified integer value or vector of all elements of that
/// value.
-struct specific_intval {
+template <unsigned BitWidth = 0> struct specific_intval {
APInt Val;
specific_intval(APInt V) : Val(std::move(V)) {}
@@ -67,14 +67,17 @@ struct specific_intval {
CI = dyn_cast_or_null<ConstantInt>(
C->getSplatValue(/*AllowPoison=*/false));
- return CI && APInt::isSameValue(CI->getValue(), Val);
+ return CI && APInt::isSameValue(CI->getValue(), Val) &&
+ (BitWidth == 0 || CI->getBitWidth() == BitWidth);
}
};
-inline specific_intval m_SpecificInt(uint64_t V) {
- return specific_intval(APInt(64, V));
+inline specific_intval<0> m_SpecificInt(uint64_t V) {
+ return specific_intval<0>(APInt(64, V));
}
+inline specific_intval<1> m_False() { return specific_intval<1>(APInt(64, 0)); }
+
/// Matching combinators
template <typename LTy, typename RTy> struct match_combine_or {
LTy L;
diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index 007dc3f89b3fb9..c1dd04a2b1c67e 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -884,18 +884,19 @@ void VPlanTransforms::clearReductionWrapFlags(VPlan &Plan) {
/// Try to simplify recipe \p R.
static void simplifyRecipe(VPRecipeBase &R, VPTypeAnalysis &TypeInfo) {
+ using namespace llvm::VPlanPatternMatch;
// Try to remove redundant blend recipes.
if (auto *Blend = dyn_cast<VPBlendRecipe>(&R)) {
VPValue *Inc0 = Blend->getIncomingValue(0);
for (unsigned I = 1; I != Blend->getNumIncomingValues(); ++I)
- if (Inc0 != Blend->getIncomingValue(I))
+ if (Inc0 != Blend->getIncomingValue(I) &&
+ !match(Blend->getMask(I), m_False()))
return;
Blend->replaceAllUsesWith(Inc0);
Blend->eraseFromParent();
return;
}
- using namespace llvm::VPlanPatternMatch;
VPValue *A;
if (match(&R, m_Trunc(m_ZExtOrSExt(m_VPValue(A))))) {
VPValue *Trunc = R.getVPSingleValue();
diff --git a/llvm/test/Transforms/LoopVectorize/unused-blend-mask-for-first-operand.ll b/llvm/test/Transforms/LoopVectorize/unused-blend-mask-for-first-operand.ll
index c622925510dd48..d0c74897f264bc 100644
--- a/llvm/test/Transforms/LoopVectorize/unused-blend-mask-for-first-operand.ll
+++ b/llvm/test/Transforms/LoopVectorize/unused-blend-mask-for-first-operand.ll
@@ -10,17 +10,13 @@ define void @test_not_first_lane_only_constant(ptr %A, ptr noalias %B) {
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 false, label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
-; CHECK-NEXT: [[BROADCAST_SPLATINSERT3:%.*]] = insertelement <4 x ptr> poison, ptr [[B]], i64 0
-; CHECK-NEXT: [[BROADCAST_SPLAT4:%.*]] = shufflevector <4 x ptr> [[BROADCAST_SPLATINSERT3]], <4 x ptr> poison, <4 x i32> zeroinitializer
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i32 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[OFFSET_IDX:%.*]] = trunc i32 [[INDEX]] to i16
; CHECK-NEXT: [[TMP0:%.*]] = add i16 [[OFFSET_IDX]], 0
; CHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds i16, ptr [[A]], i16 [[TMP0]]
-; CHECK-NEXT: [[PREDPHI:%.*]] = select <4 x i1> zeroinitializer, <4 x ptr> poison, <4 x ptr> [[BROADCAST_SPLAT4]]
-; CHECK-NEXT: [[TMP12:%.*]] = extractelement <4 x ptr> [[PREDPHI]], i32 0
-; CHECK-NEXT: [[TMP13:%.*]] = load i16, ptr [[TMP12]], align 2
+; CHECK-NEXT: [[TMP13:%.*]] = load i16, ptr %B, align 2
; CHECK-NEXT: [[BROADCAST_SPLATINSERT5:%.*]] = insertelement <4 x i16> poison, i16 [[TMP13]], i64 0
; CHECK-NEXT: [[BROADCAST_SPLAT6:%.*]] = shufflevector <4 x i16> [[BROADCAST_SPLATINSERT5]], <4 x i16> poison, <4 x i32> zeroinitializer
; CHECK-NEXT: [[TMP2:%.*]] = getelementptr inbounds i16, ptr [[TMP1]], i32 0
>From d66acc147524a333f06b2e7162ffa428b5b9728c Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Mon, 22 Apr 2024 14:07:23 +0100
Subject: [PATCH 2/2] !fixup address comments, thanks!
---
llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h b/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
index cbd53a2307a105..3547e78c5e8a96 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
+++ b/llvm/lib/Transforms/Vectorize/VPlanPatternMatch.h
@@ -66,9 +66,12 @@ template <unsigned BitWidth = 0> struct specific_intval {
if (const auto *C = dyn_cast<Constant>(V))
CI = dyn_cast_or_null<ConstantInt>(
C->getSplatValue(/*AllowPoison=*/false));
+ if (!CI)
+ return false;
- return CI && APInt::isSameValue(CI->getValue(), Val) &&
- (BitWidth == 0 || CI->getBitWidth() == BitWidth);
+ assert((BitWidth == 0 || CI->getBitWidth() == BitWidth) &&
+ "Trying the match constant with unexpected bitwidth.");
+ return APInt::isSameValue(CI->getValue(), Val);
}
};
More information about the llvm-commits
mailing list