[llvm] [Transforms] Avoid repeated hash lookups (NFC) (PR #130708)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata updated https://github.com/llvm/llvm-project/pull/130708

>From 8fe66774b06579cedcba6030bbd2b146a4755d9d Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Mon, 10 Mar 2025 10:24:12 -0700
Subject: [PATCH 1/2] [Transforms] Avoid repeated hash lookups (NFC)

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

diff --git a/llvm/lib/Transforms/IPO/SampleProfileProbe.cpp b/llvm/lib/Transforms/IPO/SampleProfileProbe.cpp
index ec2594b0d9dc1..e40b2cdc37f70 100644
--- a/llvm/lib/Transforms/IPO/SampleProfileProbe.cpp
+++ b/llvm/lib/Transforms/IPO/SampleProfileProbe.cpp
@@ -148,7 +148,8 @@ void PseudoProbeVerifier::verifyProbeFactors(
   auto &PrevProbeFactors = FunctionProbeFactors[F->getName()];
   for (const auto &I : ProbeFactors) {
     float CurProbeFactor = I.second;
-    if (PrevProbeFactors.count(I.first)) {
+    auto [It, Inserted] = PrevProbeFactors.try_emplace(I.first);
+    if (!Inserted) {
       float PrevProbeFactor = PrevProbeFactors[I.first];
       if (std::abs(CurProbeFactor - PrevProbeFactor) >
           DistributionFactorVariance) {
@@ -163,7 +164,7 @@ void PseudoProbeVerifier::verifyProbeFactors(
     }
 
     // Update
-    PrevProbeFactors[I.first] = I.second;
+    It->second = I.second;
   }
 }
 

>From 01a61c899cb7ec00db596959382bf81c70a483bf Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Tue, 11 Mar 2025 07:39:03 -0700
Subject: [PATCH 2/2] Address a comment.

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

diff --git a/llvm/lib/Transforms/IPO/SampleProfileProbe.cpp b/llvm/lib/Transforms/IPO/SampleProfileProbe.cpp
index e40b2cdc37f70..a614e2d169534 100644
--- a/llvm/lib/Transforms/IPO/SampleProfileProbe.cpp
+++ b/llvm/lib/Transforms/IPO/SampleProfileProbe.cpp
@@ -150,7 +150,7 @@ void PseudoProbeVerifier::verifyProbeFactors(
     float CurProbeFactor = I.second;
     auto [It, Inserted] = PrevProbeFactors.try_emplace(I.first);
     if (!Inserted) {
-      float PrevProbeFactor = PrevProbeFactors[I.first];
+      float PrevProbeFactor = It->second;
       if (std::abs(CurProbeFactor - PrevProbeFactor) >
           DistributionFactorVariance) {
         if (!BannerPrinted) {