[llvm] [LoopVectorize][NFC] Simplify ScaledReductionExitInstrs map (PR #123368)
David Sherwood via llvm-commits
llvm-commits at lists.llvm.org
Mon Jan 20 05:44:56 PST 2025
https://github.com/david-arm updated https://github.com/llvm/llvm-project/pull/123368
>From e94fb885d1b8379fd0b0d2c89597ca91ee2fa2b5 Mon Sep 17 00:00:00 2001
From: David Sherwood <david.sherwood at arm.com>
Date: Fri, 17 Jan 2025 16:29:54 +0000
Subject: [PATCH 1/3] [LoopVectorize][NFC] Simplify ScaledReductionExitInstrs
map
For the following variable
DenseMap<const Instruction *, std::pair<PartialReductionChain, unsigned>>
ScaledReductionExitInstrs;
we never actually need the PartialReductionChain when using the
map. I've cleaned this up so that this now becomes
DenseMap<const Instruction *, unsigned> ScaledReductionExitInstrs;
---
llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 7 ++++---
llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h | 5 ++---
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index f6f80db58cf1b0..206668bc869416 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -8711,7 +8711,8 @@ void VPRecipeBuilder::collectScaledReductions(VFRange &Range) {
PartialReductionChain Chain = Pair.first;
if (ExtendIsOnlyUsedByPartialReductions(Chain.ExtendA) &&
ExtendIsOnlyUsedByPartialReductions(Chain.ExtendB))
- ScaledReductionExitInstrs.insert(std::make_pair(Chain.Reduction, Pair));
+ ScaledReductionExitInstrs.insert(
+ std::make_pair(Chain.Reduction, Pair.second));
}
}
@@ -8803,9 +8804,9 @@ VPRecipeBuilder::tryToCreateWidenRecipe(Instruction *Instr,
Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader()));
// If the PHI is used by a partial reduction, set the scale factor.
- std::optional<std::pair<PartialReductionChain, unsigned>> Pair =
+ std::optional<unsigned> Scale =
getScaledReductionForInstr(RdxDesc.getLoopExitInstr());
- unsigned ScaleFactor = Pair ? Pair->second : 1;
+ unsigned ScaleFactor = Scale ? *Scale : 1;
PhiRecipe = new VPReductionPHIRecipe(
Phi, RdxDesc, *StartV, CM.isInLoopReduction(Phi),
CM.useOrderedReductions(RdxDesc), ScaleFactor);
diff --git a/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h b/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h
index cf653e2d3e6584..492a3b8dfad9f3 100644
--- a/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h
+++ b/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h
@@ -88,8 +88,7 @@ class VPRecipeBuilder {
/// The set of reduction exit instructions that will be scaled to
/// a smaller VF via partial reductions, paired with the scaling factor.
- DenseMap<const Instruction *, std::pair<PartialReductionChain, unsigned>>
- ScaledReductionExitInstrs;
+ DenseMap<const Instruction *, unsigned> ScaledReductionExitInstrs;
/// Check if \p I can be widened at the start of \p Range and possibly
/// decrease the range such that the returned value holds for the entire \p
@@ -157,7 +156,7 @@ class VPRecipeBuilder {
: Plan(Plan), OrigLoop(OrigLoop), TLI(TLI), TTI(TTI), Legal(Legal),
CM(CM), PSE(PSE), Builder(Builder) {}
- std::optional<std::pair<PartialReductionChain, unsigned>>
+ std::optional<unsigned>
getScaledReductionForInstr(const Instruction *ExitInst) {
auto It = ScaledReductionExitInstrs.find(ExitInst);
return It == ScaledReductionExitInstrs.end()
>From 205e6f2e10bf0958b7b94babe67269e120573719 Mon Sep 17 00:00:00 2001
From: David Sherwood <david.sherwood at arm.com>
Date: Mon, 20 Jan 2025 12:05:35 +0000
Subject: [PATCH 2/3] Address review comments
---
llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 9 ++++-----
llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h | 15 ++++++---------
2 files changed, 10 insertions(+), 14 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 206668bc869416..84718d2bc4c5e2 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -8711,8 +8711,7 @@ void VPRecipeBuilder::collectScaledReductions(VFRange &Range) {
PartialReductionChain Chain = Pair.first;
if (ExtendIsOnlyUsedByPartialReductions(Chain.ExtendA) &&
ExtendIsOnlyUsedByPartialReductions(Chain.ExtendB))
- ScaledReductionExitInstrs.insert(
- std::make_pair(Chain.Reduction, Pair.second));
+ ScaledReductionMap.insert(std::make_pair(Chain.Reduction, Pair.second));
}
}
@@ -8805,8 +8804,8 @@ VPRecipeBuilder::tryToCreateWidenRecipe(Instruction *Instr,
// If the PHI is used by a partial reduction, set the scale factor.
std::optional<unsigned> Scale =
- getScaledReductionForInstr(RdxDesc.getLoopExitInstr());
- unsigned ScaleFactor = Scale ? *Scale : 1;
+ getScalingForReduction(RdxDesc.getLoopExitInstr());
+ unsigned ScaleFactor = Scale.value_or(1);
PhiRecipe = new VPReductionPHIRecipe(
Phi, RdxDesc, *StartV, CM.isInLoopReduction(Phi),
CM.useOrderedReductions(RdxDesc), ScaleFactor);
@@ -8841,7 +8840,7 @@ VPRecipeBuilder::tryToCreateWidenRecipe(Instruction *Instr,
if (isa<LoadInst>(Instr) || isa<StoreInst>(Instr))
return tryToWidenMemory(Instr, Operands, Range);
- if (getScaledReductionForInstr(Instr))
+ if (getScalingForReduction(Instr))
return tryToCreatePartialReduction(Instr, Operands);
if (!shouldWiden(Instr, Range))
diff --git a/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h b/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h
index 492a3b8dfad9f3..44745bfd46f891 100644
--- a/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h
+++ b/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h
@@ -86,9 +86,8 @@ class VPRecipeBuilder {
/// created.
SmallVector<VPHeaderPHIRecipe *, 4> PhisToFix;
- /// The set of reduction exit instructions that will be scaled to
- /// a smaller VF via partial reductions, paired with the scaling factor.
- DenseMap<const Instruction *, unsigned> ScaledReductionExitInstrs;
+ /// A mapping of partial reduction exit instructions to their scaling factor.
+ DenseMap<const Instruction *, unsigned> ScaledReductionMap;
/// Check if \p I can be widened at the start of \p Range and possibly
/// decrease the range such that the returned value holds for the entire \p
@@ -156,12 +155,10 @@ class VPRecipeBuilder {
: Plan(Plan), OrigLoop(OrigLoop), TLI(TLI), TTI(TTI), Legal(Legal),
CM(CM), PSE(PSE), Builder(Builder) {}
- std::optional<unsigned>
- getScaledReductionForInstr(const Instruction *ExitInst) {
- auto It = ScaledReductionExitInstrs.find(ExitInst);
- return It == ScaledReductionExitInstrs.end()
- ? std::nullopt
- : std::make_optional(It->second);
+ std::optional<unsigned> getScalingForReduction(const Instruction *ExitInst) {
+ auto It = ScaledReductionMap.find(ExitInst);
+ return It == ScaledReductionMap.end() ? std::nullopt
+ : std::make_optional(It->second);
}
/// Find all possible partial reductions in the loop and track all of those
>From 1b72f0b6fa180769d0c9ba6e0d5023e42052ea30 Mon Sep 17 00:00:00 2001
From: David Sherwood <david.sherwood at arm.com>
Date: Mon, 20 Jan 2025 13:44:13 +0000
Subject: [PATCH 3/3] Address review comment
---
llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 84718d2bc4c5e2..29f3940ed6fa7a 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -8803,9 +8803,8 @@ VPRecipeBuilder::tryToCreateWidenRecipe(Instruction *Instr,
Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader()));
// If the PHI is used by a partial reduction, set the scale factor.
- std::optional<unsigned> Scale =
- getScalingForReduction(RdxDesc.getLoopExitInstr());
- unsigned ScaleFactor = Scale.value_or(1);
+ unsigned ScaleFactor =
+ getScalingForReduction(RdxDesc.getLoopExitInstr()).value_or(1);
PhiRecipe = new VPReductionPHIRecipe(
Phi, RdxDesc, *StartV, CM.isInLoopReduction(Phi),
CM.useOrderedReductions(RdxDesc), ScaleFactor);
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