[llvm] [Vectorize] Avoid repeated hash lookups (NFC) (PR #132661)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata updated https://github.com/llvm/llvm-project/pull/132661

>From 2be6684ad84b1cd77f706d333e805e47ab4b6972 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Sun, 23 Mar 2025 08:03:54 -0700
Subject: [PATCH 1/4] [Vectorize] Avoid repeated hash lookups (NFC)

---
 llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 92160a421e59c..ae55049c22338 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -5815,12 +5815,13 @@ LoopVectorizationCostModel::getReductionPatternCost(Instruction *I,
 
   // Test if the found instruction is a reduction, and if not return an invalid
   // cost specifying the parent to use the original cost modelling.
-  if (!InLoopReductionImmediateChains.count(RetI))
+  auto RetIIt = InLoopReductionImmediateChains.find(RetI);
+  if (RetIIt == InLoopReductionImmediateChains.end())
     return std::nullopt;
 
   // Find the reduction this chain is a part of and calculate the basic cost of
   // the reduction on its own.
-  Instruction *LastChain = InLoopReductionImmediateChains.at(RetI);
+  Instruction *LastChain = RetIIt->second;
   Instruction *ReductionPhi = LastChain;
   while (!isa<PHINode>(ReductionPhi))
     ReductionPhi = InLoopReductionImmediateChains.at(ReductionPhi);

>From b99b16d2bccae0f79ee56d3ef048ae312cc827d5 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Tue, 25 Mar 2025 09:19:34 -0700
Subject: [PATCH 2/4] Update llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

Co-authored-by: Florian Hahn <flo at fhahn.com>
---
 llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index ae55049c22338..407f1e1039e91 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -5815,8 +5815,8 @@ LoopVectorizationCostModel::getReductionPatternCost(Instruction *I,
 
   // Test if the found instruction is a reduction, and if not return an invalid
   // cost specifying the parent to use the original cost modelling.
-  auto RetIIt = InLoopReductionImmediateChains.find(RetI);
-  if (RetIIt == InLoopReductionImmediateChains.end())
+  Instruction *LastChain  = InLoopReductionImmediateChains.lookup(RetI);
+  if (!LastChain)
     return std::nullopt;
 
   // Find the reduction this chain is a part of and calculate the basic cost of

>From 7fa16fd269e3ede48c5f3ebc1c2272f6b68f6c44 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Tue, 25 Mar 2025 09:19:41 -0700
Subject: [PATCH 3/4] Update llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

Co-authored-by: Florian Hahn <flo at fhahn.com>
---
 llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 407f1e1039e91..294985353c9f1 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -5821,7 +5821,6 @@ LoopVectorizationCostModel::getReductionPatternCost(Instruction *I,
 
   // Find the reduction this chain is a part of and calculate the basic cost of
   // the reduction on its own.
-  Instruction *LastChain = RetIIt->second;
   Instruction *ReductionPhi = LastChain;
   while (!isa<PHINode>(ReductionPhi))
     ReductionPhi = InLoopReductionImmediateChains.at(ReductionPhi);

>From 2104a1fcd1d1369bf6d985c893ee86b3fb7fcc60 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Tue, 25 Mar 2025 09:53:14 -0700
Subject: [PATCH 4/4] Fix formatting.

---
 llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 294985353c9f1..e1bc492a8f750 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -5815,7 +5815,7 @@ LoopVectorizationCostModel::getReductionPatternCost(Instruction *I,
 
   // Test if the found instruction is a reduction, and if not return an invalid
   // cost specifying the parent to use the original cost modelling.
-  Instruction *LastChain  = InLoopReductionImmediateChains.lookup(RetI);
+  Instruction *LastChain = InLoopReductionImmediateChains.lookup(RetI);
   if (!LastChain)
     return std::nullopt;