[LV] Bundle sub reductions into VPExpressionRecipe #147255
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This PR bundles sub reductions into the VPExpressionRecipe class and adjusts the cost functions to take the negation into account.
SamTebbs33
requested review from
fhahn,
davemgreen,
huntergr-arm,
sdesmalen-arm and
david-arm
llvmbot
added
backend:ARM
backend:AArch64
vectorizers
llvm:analysis
|
@llvm/pr-subscribers-vectorizers @llvm/pr-subscribers-backend-arm Author: Sam Tebbs (SamTebbs33) ChangesThis PR bundles sub reductions into the VPExpressionRecipe class and adjusts the cost functions to take the negation into account. Patch is 23.85 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/147255.diff 14 Files Affected:
diff --git a/llvm/include/llvm/Analysis/TargetTransformInfo.h b/llvm/include/llvm/Analysis/TargetTransformInfo.h
index c43870392361d..3cc0ea01953c3 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfo.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfo.h
@@ -1645,8 +1645,10 @@ class TargetTransformInfo {
/// extensions. This is the cost of as:
/// ResTy vecreduce.add(mul (A, B)).
/// ResTy vecreduce.add(mul(ext(Ty A), ext(Ty B)).
+ /// The multiply can optionally be negated, which signifies that it is a sub
+ /// reduction.
LLVM_ABI InstructionCost getMulAccReductionCost(
- bool IsUnsigned, Type *ResTy, VectorType *Ty,
+ bool IsUnsigned, Type *ResTy, VectorType *Ty, bool Negated,
TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput) const;
/// Calculate the cost of an extended reduction pattern, similar to
diff --git a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
index 12f87226c5f57..fd22981a5dbf3 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -960,7 +960,7 @@ class TargetTransformInfoImplBase {
virtual InstructionCost
getMulAccReductionCost(bool IsUnsigned, Type *ResTy, VectorType *Ty,
- TTI::TargetCostKind CostKind) const {
+ bool Negated, TTI::TargetCostKind CostKind) const {
return 1;
}
diff --git a/llvm/include/llvm/CodeGen/BasicTTIImpl.h b/llvm/include/llvm/CodeGen/BasicTTIImpl.h
index bf958e100f2ac..a9c9fa6d1db0d 100644
--- a/llvm/include/llvm/CodeGen/BasicTTIImpl.h
+++ b/llvm/include/llvm/CodeGen/BasicTTIImpl.h
@@ -3116,7 +3116,10 @@ class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
InstructionCost
getMulAccReductionCost(bool IsUnsigned, Type *ResTy, VectorType *Ty,
+ bool Negated,
TTI::TargetCostKind CostKind) const override {
+ if (Negated)
+ return InstructionCost::getInvalid(CostKind);
// Without any native support, this is equivalent to the cost of
// vecreduce.add(mul(ext(Ty A), ext(Ty B))) or
// vecreduce.add(mul(A, B)).
diff --git a/llvm/lib/Analysis/TargetTransformInfo.cpp b/llvm/lib/Analysis/TargetTransformInfo.cpp
index 3ebd9d487ba04..ba0d070bffe6d 100644
--- a/llvm/lib/Analysis/TargetTransformInfo.cpp
+++ b/llvm/lib/Analysis/TargetTransformInfo.cpp
@@ -1274,9 +1274,10 @@ InstructionCost TargetTransformInfo::getExtendedReductionCost(
}
InstructionCost TargetTransformInfo::getMulAccReductionCost(
- bool IsUnsigned, Type *ResTy, VectorType *Ty,
+ bool IsUnsigned, Type *ResTy, VectorType *Ty, bool Negated,
TTI::TargetCostKind CostKind) const {
- return TTIImpl->getMulAccReductionCost(IsUnsigned, ResTy, Ty, CostKind);
+ return TTIImpl->getMulAccReductionCost(IsUnsigned, ResTy, Ty, Negated,
+ CostKind);
}
InstructionCost
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index 380faa6cf6939..d9a367535baf4 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -5316,8 +5316,10 @@ InstructionCost AArch64TTIImpl::getExtendedReductionCost(
InstructionCost
AArch64TTIImpl::getMulAccReductionCost(bool IsUnsigned, Type *ResTy,
- VectorType *VecTy,
+ VectorType *VecTy, bool Negated,
TTI::TargetCostKind CostKind) const {
+ if (Negated)
+ return InstructionCost::getInvalid(CostKind);
EVT VecVT = TLI->getValueType(DL, VecTy);
EVT ResVT = TLI->getValueType(DL, ResTy);
@@ -5332,7 +5334,8 @@ AArch64TTIImpl::getMulAccReductionCost(bool IsUnsigned, Type *ResTy,
return LT.first + 2;
}
- return BaseT::getMulAccReductionCost(IsUnsigned, ResTy, VecTy, CostKind);
+ return BaseT::getMulAccReductionCost(IsUnsigned, ResTy, VecTy, Negated,
+ CostKind);
}
InstructionCost
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
index 9ada70bd7086a..8bb31d2a3dac5 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
@@ -447,7 +447,7 @@ class AArch64TTIImpl final : public BasicTTIImplBase<AArch64TTIImpl> {
TTI::TargetCostKind CostKind) const override;
InstructionCost getMulAccReductionCost(
- bool IsUnsigned, Type *ResTy, VectorType *Ty,
+ bool IsUnsigned, Type *ResTy, VectorType *Ty, bool Negated,
TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput) const override;
InstructionCost
diff --git a/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp b/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
index 203fb76d7be86..27eb22b5f9986 100644
--- a/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
@@ -1884,8 +1884,10 @@ InstructionCost ARMTTIImpl::getExtendedReductionCost(
InstructionCost
ARMTTIImpl::getMulAccReductionCost(bool IsUnsigned, Type *ResTy,
- VectorType *ValTy,
+ VectorType *ValTy, bool Negated,
TTI::TargetCostKind CostKind) const {
+ if (Negated)
+ return InstructionCost::getInvalid(CostKind);
EVT ValVT = TLI->getValueType(DL, ValTy);
EVT ResVT = TLI->getValueType(DL, ResTy);
@@ -1906,7 +1908,8 @@ ARMTTIImpl::getMulAccReductionCost(bool IsUnsigned, Type *ResTy,
return ST->getMVEVectorCostFactor(CostKind) * LT.first;
}
- return BaseT::getMulAccReductionCost(IsUnsigned, ResTy, ValTy, CostKind);
+ return BaseT::getMulAccReductionCost(IsUnsigned, ResTy, ValTy, Negated,
+ CostKind);
}
InstructionCost
diff --git a/llvm/lib/Target/ARM/ARMTargetTransformInfo.h b/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
index ca06b9e3cb661..43f47f3e7aa6f 100644
--- a/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
+++ b/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
@@ -299,6 +299,7 @@ class ARMTTIImpl final : public BasicTTIImplBase<ARMTTIImpl> {
TTI::TargetCostKind CostKind) const override;
InstructionCost
getMulAccReductionCost(bool IsUnsigned, Type *ResTy, VectorType *ValTy,
+ bool Negated,
TTI::TargetCostKind CostKind) const override;
InstructionCost
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 1cfbcf1336620..0adff8d957e98 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -5538,7 +5538,7 @@ LoopVectorizationCostModel::getReductionPatternCost(Instruction *I,
TTI::CastContextHint::None, CostKind, RedOp);
InstructionCost RedCost = TTI.getMulAccReductionCost(
- IsUnsigned, RdxDesc.getRecurrenceType(), ExtType, CostKind);
+ IsUnsigned, RdxDesc.getRecurrenceType(), ExtType, false, CostKind);
if (RedCost.isValid() &&
RedCost < ExtCost * 2 + MulCost + Ext2Cost + BaseCost)
@@ -5583,7 +5583,7 @@ LoopVectorizationCostModel::getReductionPatternCost(Instruction *I,
TTI.getArithmeticInstrCost(Instruction::Mul, VectorTy, CostKind);
InstructionCost RedCost = TTI.getMulAccReductionCost(
- IsUnsigned, RdxDesc.getRecurrenceType(), ExtType, CostKind);
+ IsUnsigned, RdxDesc.getRecurrenceType(), ExtType, false, CostKind);
InstructionCost ExtraExtCost = 0;
if (Op0Ty != LargestOpTy || Op1Ty != LargestOpTy) {
Instruction *ExtraExtOp = (Op0Ty != LargestOpTy) ? Op0 : Op1;
@@ -5602,7 +5602,7 @@ LoopVectorizationCostModel::getReductionPatternCost(Instruction *I,
TTI.getArithmeticInstrCost(Instruction::Mul, VectorTy, CostKind);
InstructionCost RedCost = TTI.getMulAccReductionCost(
- true, RdxDesc.getRecurrenceType(), VectorTy, CostKind);
+ true, RdxDesc.getRecurrenceType(), VectorTy, false, CostKind);
if (RedCost.isValid() && RedCost < MulCost + BaseCost)
return I == RetI ? RedCost : 0;
diff --git a/llvm/lib/Transforms/Vectorize/VPlan.h b/llvm/lib/Transforms/Vectorize/VPlan.h
index d460573f5bec6..1bc926db301d8 100644
--- a/llvm/lib/Transforms/Vectorize/VPlan.h
+++ b/llvm/lib/Transforms/Vectorize/VPlan.h
@@ -2757,6 +2757,12 @@ class VPExpressionRecipe : public VPSingleDefRecipe {
/// vector operands, performing a reduction.add on the result, and adding
/// the scalar result to a chain.
MulAccReduction,
+ /// Represent an inloop multiply-accumulate reduction, multiplying the
+ /// extended vector operands, negating the multiplication, performing a
+ /// reduction.add
+ /// on the result, and adding
+ /// the scalar result to a chain.
+ ExtNegatedMulAccReduction,
};
/// Type of the expression.
@@ -2780,6 +2786,11 @@ class VPExpressionRecipe : public VPSingleDefRecipe {
VPWidenRecipe *Mul, VPReductionRecipe *Red)
: VPExpressionRecipe(ExpressionTypes::ExtMulAccReduction,
{Ext0, Ext1, Mul, Red}) {}
+ VPExpressionRecipe(VPWidenCastRecipe *Ext0, VPWidenCastRecipe *Ext1,
+ VPWidenRecipe *Mul, VPWidenRecipe *Sub,
+ VPReductionRecipe *Red)
+ : VPExpressionRecipe(ExpressionTypes::ExtNegatedMulAccReduction,
+ {Ext0, Ext1, Mul, Sub, Red}) {}
~VPExpressionRecipe() override {
for (auto *R : reverse(ExpressionRecipes))
diff --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index 318e8171e098d..c20b1920c3791 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -2672,13 +2672,17 @@ InstructionCost VPExpressionRecipe::computeCost(ElementCount VF,
RedTy, SrcVecTy, std::nullopt, Ctx.CostKind);
}
case ExpressionTypes::MulAccReduction:
- return Ctx.TTI.getMulAccReductionCost(false, RedTy, SrcVecTy, Ctx.CostKind);
+ return Ctx.TTI.getMulAccReductionCost(false, RedTy, SrcVecTy, false,
+ Ctx.CostKind);
- case ExpressionTypes::ExtMulAccReduction:
+ case ExpressionTypes::ExtNegatedMulAccReduction:
+ case ExpressionTypes::ExtMulAccReduction: {
+ bool Negated = ExpressionType == ExpressionTypes::ExtNegatedMulAccReduction;
return Ctx.TTI.getMulAccReductionCost(
cast<VPWidenCastRecipe>(ExpressionRecipes.front())->getOpcode() ==
Instruction::ZExt,
- RedTy, SrcVecTy, Ctx.CostKind);
+ RedTy, SrcVecTy, Negated, Ctx.CostKind);
+ }
}
llvm_unreachable("Unknown VPExpressionRecipe::ExpressionTypes enum");
}
@@ -2725,6 +2729,31 @@ void VPExpressionRecipe::print(raw_ostream &O, const Twine &Indent,
O << ")";
break;
}
+ case ExpressionTypes::ExtNegatedMulAccReduction: {
+ getOperand(getNumOperands() - 1)->printAsOperand(O, SlotTracker);
+ O << " + ";
+ O << "reduce."
+ << Instruction::getOpcodeName(
+ RecurrenceDescriptor::getOpcode(Red->getRecurrenceKind()))
+ << " (sub (0, mul";
+ auto *Mul = cast<VPWidenRecipe>(ExpressionRecipes[2]);
+ Mul->printFlags(O);
+ O << "(";
+ getOperand(0)->printAsOperand(O, SlotTracker);
+ auto *Ext0 = cast<VPWidenCastRecipe>(ExpressionRecipes[0]);
+ O << " " << Instruction::getOpcodeName(Ext0->getOpcode()) << " to "
+ << *Ext0->getResultType() << "), (";
+ getOperand(1)->printAsOperand(O, SlotTracker);
+ auto *Ext1 = cast<VPWidenCastRecipe>(ExpressionRecipes[1]);
+ O << " " << Instruction::getOpcodeName(Ext1->getOpcode()) << " to "
+ << *Ext1->getResultType() << ")";
+ if (Red->isConditional()) {
+ O << ", ";
+ Red->getCondOp()->printAsOperand(O, SlotTracker);
+ }
+ O << "))";
+ break;
+ }
case ExpressionTypes::MulAccReduction:
case ExpressionTypes::ExtMulAccReduction: {
getOperand(getNumOperands() - 1)->printAsOperand(O, SlotTracker);
diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index 931d4d42f56e4..a09d2037e97b4 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -2908,16 +2908,17 @@ tryToMatchAndCreateMulAccumulateReduction(VPReductionRecipe *Red,
// Clamp the range if using multiply-accumulate-reduction is profitable.
auto IsMulAccValidAndClampRange =
- [&](bool isZExt, VPWidenRecipe *Mul, VPWidenCastRecipe *Ext0,
- VPWidenCastRecipe *Ext1, VPWidenCastRecipe *OuterExt) -> bool {
+ [&](bool IsZExt, VPWidenRecipe *Mul, VPWidenCastRecipe *Ext0,
+ VPWidenCastRecipe *Ext1, VPWidenCastRecipe *OuterExt,
+ bool Negated = false) -> bool {
return LoopVectorizationPlanner::getDecisionAndClampRange(
[&](ElementCount VF) {
TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput;
Type *SrcTy =
Ext0 ? Ctx.Types.inferScalarType(Ext0->getOperand(0)) : RedTy;
auto *SrcVecTy = cast<VectorType>(toVectorTy(SrcTy, VF));
- InstructionCost MulAccCost =
- Ctx.TTI.getMulAccReductionCost(isZExt, RedTy, SrcVecTy, CostKind);
+ InstructionCost MulAccCost = Ctx.TTI.getMulAccReductionCost(
+ IsZExt, RedTy, SrcVecTy, Negated, CostKind);
InstructionCost MulCost = Mul->computeCost(VF, Ctx);
InstructionCost RedCost = Red->computeCost(VF, Ctx);
InstructionCost ExtCost = 0;
@@ -2935,14 +2936,22 @@ tryToMatchAndCreateMulAccumulateReduction(VPReductionRecipe *Red,
};
VPValue *VecOp = Red->getVecOp();
+ VPValue *Mul = nullptr;
+ VPValue *Sub = nullptr;
VPValue *A, *B;
+ // Sub reductions will have a sub between the add reduction and vec op.
+ if (match(VecOp,
+ m_Binary<Instruction::Sub>(m_SpecificInt(0), m_VPValue(Mul))))
+ Sub = VecOp;
+ else
+ Mul = VecOp;
// Try to match reduce.add(mul(...)).
- if (match(VecOp, m_Mul(m_VPValue(A), m_VPValue(B)))) {
+ if (match(Mul, m_Mul(m_VPValue(A), m_VPValue(B)))) {
auto *RecipeA =
dyn_cast_if_present<VPWidenCastRecipe>(A->getDefiningRecipe());
auto *RecipeB =
dyn_cast_if_present<VPWidenCastRecipe>(B->getDefiningRecipe());
- auto *Mul = cast<VPWidenRecipe>(VecOp->getDefiningRecipe());
+ auto *MulR = cast<VPWidenRecipe>(Mul->getDefiningRecipe());
// Match reduce.add(mul(ext, ext)).
if (RecipeA && RecipeB &&
@@ -2951,12 +2960,16 @@ tryToMatchAndCreateMulAccumulateReduction(VPReductionRecipe *Red,
match(RecipeB, m_ZExtOrSExt(m_VPValue())) &&
IsMulAccValidAndClampRange(RecipeA->getOpcode() ==
Instruction::CastOps::ZExt,
- Mul, RecipeA, RecipeB, nullptr)) {
- return new VPExpressionRecipe(RecipeA, RecipeB, Mul, Red);
+ MulR, RecipeA, RecipeB, nullptr, Sub)) {
+ if (Sub)
+ return new VPExpressionRecipe(
+ RecipeA, RecipeB, MulR,
+ cast<VPWidenRecipe>(Sub->getDefiningRecipe()), Red);
+ return new VPExpressionRecipe(RecipeA, RecipeB, MulR, Red);
}
// Match reduce.add(mul).
- if (IsMulAccValidAndClampRange(true, Mul, nullptr, nullptr, nullptr))
- return new VPExpressionRecipe(Mul, Red);
+ if (IsMulAccValidAndClampRange(true, MulR, nullptr, nullptr, nullptr, Sub))
+ return new VPExpressionRecipe(MulR, Red);
}
// Match reduce.add(ext(mul(ext(A), ext(B)))).
// All extend recipes must have same opcode or A == B
diff --git a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
index b2fced47b9527..7953aec48c8b0 100644
--- a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
+++ b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
@@ -1401,8 +1401,8 @@ static void analyzeCostOfVecReduction(const IntrinsicInst &II,
TTI::CastContextHint::None, CostKind, RedOp);
CostBeforeReduction = ExtCost * 2 + MulCost + Ext2Cost;
- CostAfterReduction =
- TTI.getMulAccReductionCost(IsUnsigned, II.getType(), ExtType, CostKind);
+ CostAfterReduction = TTI.getMulAccReductionCost(IsUnsigned, II.getType(),
+ ExtType, false, CostKind);
return;
}
CostAfterReduction = TTI.getArithmeticReductionCost(ReductionOpc, VecRedTy,
diff --git a/llvm/test/Transforms/LoopVectorize/vplan-printing-reductions.ll b/llvm/test/Transforms/LoopVectorize/vplan-printing-reductions.ll
index 4af3fa9202c77..8059ac12ecd2e 100644
--- a/llvm/test/Transforms/LoopVectorize/vplan-printing-reductions.ll
+++ b/llvm/test/Transforms/LoopVectorize/vplan-printing-reductions.ll
@@ -416,3 +416,146 @@ exit:
%r.0.lcssa = phi i64 [ %rdx.next, %loop ]
ret i64 %r.0.lcssa
}
+
+define i32 @print_mulacc_sub(ptr %a, ptr %b) {
+; CHECK: VPlan 'Initial VPlan for VF={4},UF>=1' {
+; CHECK-NEXT: Live-in vp<%0> = VF
+; CHECK-NEXT: Live-in vp<%1> = VF * UF
+; CHECK-NEXT: Live-in vp<%2> = vector-trip-count
+; CHECK-NEXT: Live-in ir<1024> = original trip-count
+; CHECK-EMPTY:
+; CHECK-NEXT: ir-bb<entry>:
+; CHECK-NEXT: Successor(s): scalar.ph, vector.ph
+; CHECK-EMPTY:
+; CHECK-NEXT: vector.ph:
+; CHECK-NEXT: EMIT vp<%3> = reduction-start-vector ir<0>, ir<0>, ir<1>
+; CHECK-NEXT: Successor(s): vector loop
+; CHECK-EMPTY:
+; CHECK-NEXT: <x1> vector loop: {
+; CHECK-NEXT: vector.body:
+; CHECK-NEXT: EMIT vp<%4> = CANONICAL-INDUCTION ir<0>, vp<%index.next>
+; CHECK-NEXT: WIDEN-REDUCTION-PHI ir<%accum> = phi vp<%3>, vp<%8>
+; CHECK-NEXT: vp<%5> = SCALAR-STEPS vp<%4>, ir<1>, vp<%0>
+; CHECK-NEXT: CLONE ir<%gep.a> = getelementptr ir<%a>, vp<%5>
+; CHECK-NEXT: vp<%6> = vector-pointer ir<%gep.a>
+; CHECK-NEXT: WIDEN ir<%load.a> = load vp<%6>
+; CHECK-NEXT: CLONE ir<%gep.b> = getelementptr ir<%b>, vp<%5>
+; CHECK-NEXT: vp<%7> = vector-pointer ir<%gep.b>
+; CHECK-NEXT: WIDEN ir<%load.b> = load vp<%7>
+; CHECK-NEXT: EXPRESSION vp<%8> = ir<%accum> + reduce.add (sub (0, mul (ir<%load.b> zext to i32), (ir<%load.a> zext to i32)))
+; CHECK-NEXT: EMIT vp<%index.next> = add nuw vp<%4>, vp<%1>
+; CHECK-NEXT: EMIT branch-on-count vp<%index.next>, vp<%2>
+; CHECK-NEXT: No successors
+; CHECK-NEXT: }
+; CHECK-NEXT: Successor(s): middle.block
+; CHECK-EMPTY:
+; CHECK-NEXT: middle.block:
+; CHECK-NEXT: EMIT vp<%10> = compute-reduction-result ir<%accum>, vp<%8>
+; CHECK-NEXT: EMIT vp<%cmp.n> = icmp eq ir<1024>, vp<%2>
+; CHECK-NEXT: EMIT branch-on-cond vp<%cmp.n>
+; CHECK-NEXT: Successor(s): ir-bb<for.exit>, scalar.ph
+; CHECK-EMPTY:
+; CHECK-NEXT: ir-bb<for.exit>:
+; CHECK-NEXT: IR %add.lcssa = phi i32 [ %add, %for.body ] (extra operand: vp<%10> from middle.block)
+; CHECK-NEXT: No successors
+; CHECK-EMPTY:
+; CHECK-NEXT: scalar.ph:
+; CHECK-NEXT: EMIT-SCALAR vp<%bc.resume.val> = phi [ vp<%2>, middle.block ], [ ir<0>, ir-bb<entry> ]
+; CHECK-NEXT: EMIT-SCALAR vp<%bc.merge.rdx> = phi [ vp<%10>, middle.block ], [ ir<0>, ir-bb<entry> ]
+; CHECK-NEXT: Successor(s): ir-bb<for.body>
+; CHECK-EMPTY:
+; CHECK-NEXT: ir-bb<for.body>:
+; CHECK-NEXT: IR %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.body ] (extra operand: vp<%bc.resume.val> from scalar.ph)
+; CHECK-NEXT: IR %accum = phi i32 [ 0, %entry ], [ %add, %for.body ] (extra operand: vp<%bc.merge.rdx> from scalar.ph)
+; CHECK-NEXT: IR %gep.a = getelementptr i8, ptr %a, i64 %iv
+; CHECK-NEXT: IR %load.a = load i8, ptr %gep.a, align 1
+; CHECK-NEXT: IR %ext.a = zext i8 %load.a to i32
+; CHECK-NEXT: IR %gep.b = getelementptr i8, ptr %b, i64 %iv
+; CHECK-NEXT: IR %load.b = load i8, ptr %gep.b, align 1
+; CHECK-NEXT: IR %ext.b = zext i8 %load.b to i32
+; CHECK-NEXT: IR %mul = mul i32 %ext.b, %ext.a
+; CHECK-NEXT: IR %add = sub i32 %accum, %mul
+; CHECK-NEXT: IR %iv.next = add i64 %iv, 1
+; CHECK-NEXT: IR %exitcond.not = icmp eq i64 %iv.next, 1024
+; CHECK-NEXT: No successors
+; CH...
[truncated]
|
david-arm
reviewed
Jul 7, 2025
| @@ -2725,6 +2729,31 @@ void VPExpressionRecipe::print(raw_ostream &O, const Twine &Indent, | |||
| O << ")"; | |||
| break; | |||
| } | |||
| case ExpressionTypes::ExtNegatedMulAccReduction: { | |||
There was a problem hiding this comment.
Is there a way to commonise this with the ExtMulAccReduction case if the only difference is a negate?
There was a problem hiding this comment.
That was my initial approach but it required checking the number of operands to know if there was a sub or not, and I was asked to create an expression type to not rely on operand ordering being stable.
| CostAfterReduction = | ||
| TTI.getMulAccReductionCost(IsUnsigned, II.getType(), ExtType, CostKind); | ||
| CostAfterReduction = TTI.getMulAccReductionCost(IsUnsigned, II.getType(), | ||
| ExtType, false, CostKind); |
There was a problem hiding this comment.
nit: Probably better written as /*Negated=*/false
| LLVM_ABI InstructionCost getMulAccReductionCost( | ||
| bool IsUnsigned, Type *ResTy, VectorType *Ty, | ||
| bool IsUnsigned, Type *ResTy, VectorType *Ty, bool Negated, |
There was a problem hiding this comment.
Is it worth keeping the booleans together, i.e. next to IsUnsigned?
There was a problem hiding this comment.
Good idea, done.
| TTI::TargetCostKind CostKind) const override { | ||
| if (Negated) |
There was a problem hiding this comment.
Why can't we add a cost for this?
There was a problem hiding this comment.
Thanks, I've added a cost for the sub.
| @@ -5538,7 +5538,7 @@ LoopVectorizationCostModel::getReductionPatternCost(Instruction *I, | |||
| TTI::CastContextHint::None, CostKind, RedOp); | |||
|
|
|||
| InstructionCost RedCost = TTI.getMulAccReductionCost( | |||
| IsUnsigned, RdxDesc.getRecurrenceType(), ExtType, CostKind); | |||
| IsUnsigned, RdxDesc.getRecurrenceType(), ExtType, false, CostKind); | |||
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nit: /*Negated=*/false and same for other below.
| /// Represent an inloop multiply-accumulate reduction, multiplying the | ||
| /// extended vector operands, negating the multiplication, performing a | ||
| /// reduction.add | ||
| /// on the result, and adding |
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Formatting of the comment looks a bit odd - can you fix it?
SamTebbs33
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This PR bundles partial reductions inside the VPExpressionRecipe class. Depends on llvm#147255 .
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This PR bundles sub reductions into the VPExpressionRecipe class and adjusts the cost functions to take the negation into account.