[llvm] [SLP] Exit early if MaxVF < MinVF (NFCI). (PR #83283)
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Fri Mar 1 08:31:38 PST 2024
https://github.com/fhahn updated https://github.com/llvm/llvm-project/pull/83283
>From 3eacfa64a35f0aed09180c00cbb5272c4a4c9ca0 Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Wed, 28 Feb 2024 16:03:14 +0000
Subject: [PATCH 1/4] [SLP] Exit early if MaxVF < MinVF (NFCI).
Exit early if MaxVF < MinVF. In that case, the loop body below will
never get entered. Note that this adjusts the condition from MaxVF <=
MinVF. If MaxVF == MinVF, vectorization may still be feasible (and the
loop below gets entered).
---
llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 2b7d518c1c1a78..e381cd2c5794b1 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -13912,10 +13912,11 @@ bool SLPVectorizerPass::vectorizeStores(ArrayRef<StoreInst *> Stores,
unsigned MinVF = TTI->getStoreMinimumVF(
R.getMinVF(DL->getTypeSizeInBits(ValueTy)), StoreTy, ValueTy);
- if (MaxVF <= MinVF) {
+ if (MaxVF < MinVF) {
LLVM_DEBUG(dbgs() << "SLP: Vectorization infeasible as MaxVF (" << MaxVF
<< ") <= "
<< "MinVF (" << MinVF << ")\n");
+ return;
}
// FIXME: Is division-by-2 the correct step? Should we assert that the
>From 2cf3548f73906e5db5cf4d6223762ec25eb575f5 Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Wed, 28 Feb 2024 16:16:26 +0000
Subject: [PATCH 2/4] !fixup <= -> < in debug output
---
llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index e381cd2c5794b1..47acf2dd8c361b 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -13914,7 +13914,7 @@ bool SLPVectorizerPass::vectorizeStores(ArrayRef<StoreInst *> Stores,
if (MaxVF < MinVF) {
LLVM_DEBUG(dbgs() << "SLP: Vectorization infeasible as MaxVF (" << MaxVF
- << ") <= "
+ << ") < "
<< "MinVF (" << MinVF << ")\n");
return;
}
>From 7e52dbb432e959d1c9d15118d68faa163711f9e7 Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Wed, 28 Feb 2024 21:53:05 +0000
Subject: [PATCH 3/4] !fixup use continue instead return, scope exit to update
Operands/PrevDist.
---
.../lib/Transforms/Vectorize/SLPVectorizer.cpp | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 47acf2dd8c361b..e6306a971abdc0 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -30,6 +30,7 @@
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/iterator.h"
#include "llvm/ADT/iterator_range.h"
+#include "llvm/ADT/ScopeExit.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CodeMetrics.h"
@@ -13891,12 +13892,16 @@ bool SLPVectorizerPass::vectorizeStores(ArrayRef<StoreInst *> Stores,
if (Idx != Set.size() - 1)
continue;
}
- if (Operands.size() <= 1) {
+ // Capturing structured bindings are a C++ 20 extension, so use a separate variable for now.
+ auto &DataVar = Data;
+ auto E = make_scope_exit([&]() {
Operands.clear();
- Operands.push_back(Stores[Data.first]);
- PrevDist = Data.second;
+ Operands.push_back(Stores[DataVar.first]);
+ PrevDist = DataVar.second;
+ });
+
+ if (Operands.size() <= 1)
continue;
- }
unsigned MaxVecRegSize = R.getMaxVecRegSize();
unsigned EltSize = R.getVectorElementSize(Operands[0]);
@@ -13916,7 +13921,7 @@ bool SLPVectorizerPass::vectorizeStores(ArrayRef<StoreInst *> Stores,
LLVM_DEBUG(dbgs() << "SLP: Vectorization infeasible as MaxVF (" << MaxVF
<< ") < "
<< "MinVF (" << MinVF << ")\n");
- return;
+ continue;
}
// FIXME: Is division-by-2 the correct step? Should we assert that the
@@ -13956,9 +13961,6 @@ bool SLPVectorizerPass::vectorizeStores(ArrayRef<StoreInst *> Stores,
if (StartIdx >= Operands.size())
break;
}
- Operands.clear();
- Operands.push_back(Stores[Data.first]);
- PrevDist = Data.second;
}
};
>From 89c1415d99feac61e42aa60360bf81274baec755 Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Wed, 28 Feb 2024 21:57:54 +0000
Subject: [PATCH 4/4] !fixup fix formatting.
---
llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index e6306a971abdc0..cccb6871ed8eb1 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -21,6 +21,7 @@
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/PriorityQueue.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SetOperations.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallBitVector.h"
@@ -30,7 +31,6 @@
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/iterator.h"
#include "llvm/ADT/iterator_range.h"
-#include "llvm/ADT/ScopeExit.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CodeMetrics.h"
@@ -13892,8 +13892,9 @@ bool SLPVectorizerPass::vectorizeStores(ArrayRef<StoreInst *> Stores,
if (Idx != Set.size() - 1)
continue;
}
- // Capturing structured bindings are a C++ 20 extension, so use a separate variable for now.
- auto &DataVar = Data;
+ // Capturing structured bindings are a C++ 20 extension, so use a separate
+ // variable for now.
+ auto &DataVar = Data;
auto E = make_scope_exit([&]() {
Operands.clear();
Operands.push_back(Stores[DataVar.first]);
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