llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-vectorizers
@llvm/pr-subscribers-llvm-transforms
Author: David Sherwood (david-arm)
<details>
<summary>Changes</summary>
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;
---
Full diff: https://github.com/llvm/llvm-project/pull/123368.diff
2 Files Affected:
- (modified) llvm/lib/Transforms/Vectorize/LoopVectorize.cpp (+4-3)
- (modified) llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h (+2-3)
``````````diff
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 6df11abda9e988..a8da280438b998 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -8821,7 +8821,8 @@ 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));
}
}
@@ -8913,9 +8914,9 @@ 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()
``````````
</details>
https://github.com/llvm/llvm-project/pull/123368