[CodeGen] Avoid repeated hash lookups (NFC) (#107759)

kazutakahirata · web-flow · commit 08085eddfdca · 2024-09-08T09:04:20.000-07:00
diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -2595,12 +2595,7 @@ void CoverageMappingModuleGen::emit() {
 }
 
 unsigned CoverageMappingModuleGen::getFileID(FileEntryRef File) {
-  auto It = FileEntries.find(File);
-  if (It != FileEntries.end())
-    return It->second;
-  unsigned FileID = FileEntries.size() + 1;
-  FileEntries.insert(std::make_pair(File, FileID));
-  return FileID;
+  return FileEntries.try_emplace(File, FileEntries.size() + 1).first->second;
 }
 
 void CoverageMappingGen::emitCounterMapping(const Decl *D,

Original file line number	Diff line number	Diff line change
`@@ -2595,12 +2595,7 @@ void CoverageMappingModuleGen::emit() {`
`2595`	`2595`	`}`
`2596`	`2596`
`2597`	`2597`	`unsigned CoverageMappingModuleGen::getFileID(FileEntryRef File) {`
`2598`		`- auto It = FileEntries.find(File);`
`2599`		`- if (It != FileEntries.end())`
`2600`		`- return It->second;`
`2601`		`- unsigned FileID = FileEntries.size() + 1;`
`2602`		`- FileEntries.insert(std::make_pair(File, FileID));`
`2603`		`- return FileID;`
	`2598`	`+ return FileEntries.try_emplace(File, FileEntries.size() + 1).first->second;`
`2604`	`2599`	`}`
`2605`	`2600`
`2606`	`2601`	`void CoverageMappingGen::emitCounterMapping(const Decl *D,`