[llvm] [FileCheck] Avoid repeated hash lookups (NFC) (PR #131553)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/131553

None

>From e6e5415f67579cc9c8ee15d35c7f7a4128be19b9 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Sun, 16 Mar 2025 09:37:13 -0700
Subject: [PATCH] [FileCheck] Avoid repeated hash lookups (NFC)

---
 llvm/lib/FileCheck/FileCheck.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/FileCheck/FileCheck.cpp b/llvm/lib/FileCheck/FileCheck.cpp
index 931a4d3c36f16..072dbefba1f1f 100644
--- a/llvm/lib/FileCheck/FileCheck.cpp
+++ b/llvm/lib/FileCheck/FileCheck.cpp
@@ -1010,8 +1010,10 @@ bool Pattern::parsePattern(StringRef PatternStr, StringRef Prefix,
         // Handle substitution of string variables that were defined earlier on
         // the same line by emitting a backreference. Expressions do not
         // support substituting a numeric variable defined on the same line.
-        if (!IsNumBlock && VariableDefs.find(SubstStr) != VariableDefs.end()) {
-          unsigned CaptureParenGroup = VariableDefs[SubstStr];
+        decltype(VariableDefs)::iterator It;
+        if (!IsNumBlock &&
+            (It = VariableDefs.find(SubstStr)) != VariableDefs.end()) {
+          unsigned CaptureParenGroup = It->second;
           if (CaptureParenGroup < 1 || CaptureParenGroup > 9) {
             SM.PrintMessage(SMLoc::getFromPointer(SubstStr.data()),
                             SourceMgr::DK_Error,