[DebugInfo] Avoid repeated hash lookups (NFC) (#128632)

kazutakahirata · web-flow · commit 38f8ca1d1817 · 2025-02-25T09:02:52.000-08:00
diff --git a/llvm/lib/DebugInfo/LogicalView/Readers/LVCodeViewReader.cpp b/llvm/lib/DebugInfo/LogicalView/Readers/LVCodeViewReader.cpp
@@ -721,12 +721,11 @@ Error LVCodeViewReader::traverseSymbolSection(StringRef SectionName,
                                    getFileName());
 
         LLVM_DEBUG({ W.printString("Symbol Name", SymbolName); });
-        if (FunctionLineTables.count(SymbolName) != 0) {
+        if (!FunctionLineTables.try_emplace(SymbolName, Contents).second) {
           // Saw debug info for this function already?
           return createStringError(object_error::parse_failed, getFileName());
         }
 
-        FunctionLineTables[SymbolName] = Contents;
         SymbolNames.push_back(SymbolName);
       }
       break;

Original file line number	Diff line number	Diff line change
`@@ -721,12 +721,11 @@ Error LVCodeViewReader::traverseSymbolSection(StringRef SectionName,`
`721`	`721`	`getFileName());`
`722`	`722`
`723`	`723`	`LLVM_DEBUG({ W.printString("Symbol Name", SymbolName); });`
`724`		`- if (FunctionLineTables.count(SymbolName) != 0) {`
	`724`	`+ if (!FunctionLineTables.try_emplace(SymbolName, Contents).second) {`
`725`	`725`	`// Saw debug info for this function already?`
`726`	`726`	`return createStringError(object_error::parse_failed, getFileName());`
`727`	`727`	`}`
`728`	`728`
`729`		`- FunctionLineTables[SymbolName] = Contents;`
`730`	`729`	`SymbolNames.push_back(SymbolName);`
`731`	`730`	`}`
`732`	`731`	`break;`