[llvm] b3edc76 - [VPlan] Implement VPWidenCastRecipe::computeCost(). (NFCI) (#111339)
via llvm-commits
llvm-commits at lists.llvm.org
Mon Oct 21 21:23:53 PDT 2024
Author: Elvis Wang
Date: 2024-10-22T12:23:49+08:00
New Revision: b3edc764f70f4e56807af60abdcfbef4dbdc5d95
URL: https://github.com/llvm/llvm-project/commit/b3edc764f70f4e56807af60abdcfbef4dbdc5d95
DIFF: https://github.com/llvm/llvm-project/commit/b3edc764f70f4e56807af60abdcfbef4dbdc5d95.diff
LOG: [VPlan] Implement VPWidenCastRecipe::computeCost(). (NFCI) (#111339)
This patch implement `VPWidenCastRecipe::computeCost()` and skip cast
recipies in the in-loop reduction.
Added:
Modified:
llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
llvm/lib/Transforms/Vectorize/VPlan.h
llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
llvm/lib/Transforms/Vectorize/VPlanValue.h
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index e8653498d32a12..a88989aa2829b1 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -7307,12 +7307,30 @@ LoopVectorizationPlanner::precomputeCosts(VPlan &Plan, ElementCount VF,
const auto &ChainOps = RdxDesc.getReductionOpChain(RedPhi, OrigLoop);
SetVector<Instruction *> ChainOpsAndOperands(ChainOps.begin(),
ChainOps.end());
+ auto IsZExtOrSExt = [](const unsigned Opcode) -> bool {
+ return Opcode == Instruction::ZExt || Opcode == Instruction::SExt;
+ };
// Also include the operands of instructions in the chain, as the cost-model
// may mark extends as free.
+ //
+ // For ARM, some of the instruction can folded into the reducion
+ // instruction. So we need to mark all folded instructions free.
+ // For example: We can fold reduce(mul(ext(A), ext(B))) into one
+ // instruction.
for (auto *ChainOp : ChainOps) {
for (Value *Op : ChainOp->operands()) {
- if (auto *I = dyn_cast<Instruction>(Op))
+ if (auto *I = dyn_cast<Instruction>(Op)) {
ChainOpsAndOperands.insert(I);
+ if (I->getOpcode() == Instruction::Mul) {
+ auto *Ext0 = dyn_cast<Instruction>(I->getOperand(0));
+ auto *Ext1 = dyn_cast<Instruction>(I->getOperand(1));
+ if (Ext0 && IsZExtOrSExt(Ext0->getOpcode()) && Ext1 &&
+ Ext0->getOpcode() == Ext1->getOpcode()) {
+ ChainOpsAndOperands.insert(Ext0);
+ ChainOpsAndOperands.insert(Ext1);
+ }
+ }
+ }
}
}
diff --git a/llvm/lib/Transforms/Vectorize/VPlan.h b/llvm/lib/Transforms/Vectorize/VPlan.h
index 8dff800a0b2224..0ea73229f1eceb 100644
--- a/llvm/lib/Transforms/Vectorize/VPlan.h
+++ b/llvm/lib/Transforms/Vectorize/VPlan.h
@@ -1603,6 +1603,10 @@ class VPWidenCastRecipe : public VPRecipeWithIRFlags {
/// Produce widened copies of the cast.
void execute(VPTransformState &State) override;
+ /// Return the cost of this VPWidenCastRecipe.
+ InstructionCost computeCost(ElementCount VF,
+ VPCostContext &Ctx) const override;
+
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
/// Print the recipe.
void print(raw_ostream &O, const Twine &Indent,
diff --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index 3038f982fc814b..0eb4f7c7c88cee 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -1522,6 +1522,55 @@ void VPWidenCastRecipe::execute(VPTransformState &State) {
State.addMetadata(Cast, cast_or_null<Instruction>(getUnderlyingValue()));
}
+InstructionCost VPWidenCastRecipe::computeCost(ElementCount VF,
+ VPCostContext &Ctx) const {
+ // Computes the CastContextHint from a recipes that may access memory.
+ auto ComputeCCH = [&](const VPRecipeBase *R) -> TTI::CastContextHint {
+ if (VF.isScalar())
+ return TTI::CastContextHint::Normal;
+ if (isa<VPInterleaveRecipe>(R))
+ return TTI::CastContextHint::Interleave;
+ if (const auto *ReplicateRecipe = dyn_cast<VPReplicateRecipe>(R))
+ return ReplicateRecipe->isPredicated() ? TTI::CastContextHint::Masked
+ : TTI::CastContextHint::Normal;
+ const auto *WidenMemoryRecipe = dyn_cast<VPWidenMemoryRecipe>(R);
+ if (WidenMemoryRecipe == nullptr)
+ return TTI::CastContextHint::None;
+ if (!WidenMemoryRecipe->isConsecutive())
+ return TTI::CastContextHint::GatherScatter;
+ if (WidenMemoryRecipe->isReverse())
+ return TTI::CastContextHint::Reversed;
+ if (WidenMemoryRecipe->isMasked())
+ return TTI::CastContextHint::Masked;
+ return TTI::CastContextHint::Normal;
+ };
+
+ VPValue *Operand = getOperand(0);
+ TTI::CastContextHint CCH = TTI::CastContextHint::None;
+ // For Trunc/FPTrunc, get the context from the only user.
+ if ((Opcode == Instruction::Trunc || Opcode == Instruction::FPTrunc) &&
+ !hasMoreThanOneUniqueUser() && getNumUsers() > 0) {
+ if (auto *StoreRecipe = dyn_cast<VPRecipeBase>(*user_begin()))
+ CCH = ComputeCCH(StoreRecipe);
+ }
+ // For Z/Sext, get the context from the operand.
+ else if (Opcode == Instruction::ZExt || Opcode == Instruction::SExt ||
+ Opcode == Instruction::FPExt) {
+ if (Operand->isLiveIn())
+ CCH = TTI::CastContextHint::Normal;
+ else if (Operand->getDefiningRecipe())
+ CCH = ComputeCCH(Operand->getDefiningRecipe());
+ }
+
+ auto *SrcTy =
+ cast<VectorType>(ToVectorTy(Ctx.Types.inferScalarType(Operand), VF));
+ auto *DestTy = cast<VectorType>(ToVectorTy(getResultType(), VF));
+ // Arm TTI will use the underlying instruction to determine the cost.
+ return Ctx.TTI.getCastInstrCost(
+ Opcode, DestTy, SrcTy, CCH, TTI::TCK_RecipThroughput,
+ dyn_cast_if_present<Instruction>(getUnderlyingValue()));
+}
+
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void VPWidenCastRecipe::print(raw_ostream &O, const Twine &Indent,
VPSlotTracker &SlotTracker) const {
diff --git a/llvm/lib/Transforms/Vectorize/VPlanValue.h b/llvm/lib/Transforms/Vectorize/VPlanValue.h
index f2978b0a758b6a..1900182f76e071 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanValue.h
+++ b/llvm/lib/Transforms/Vectorize/VPlanValue.h
@@ -135,7 +135,7 @@ class VPValue {
}
/// Returns true if the value has more than one unique user.
- bool hasMoreThanOneUniqueUser() {
+ bool hasMoreThanOneUniqueUser() const {
if (getNumUsers() == 0)
return false;
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