[sancov] Avoid repeated map lookups (NFC) (#113026)

kazutakahirata · web-flow · commit 3bddf85e5274 · 2024-10-20T10:41:42.000-07:00
diff --git a/llvm/tools/sancov/sancov.cpp b/llvm/tools/sancov/sancov.cpp
@@ -961,10 +961,9 @@ static FunctionLocs resolveFunctions(const SymbolizedCoverage &Coverage,
         continue;
 
       auto P = std::make_pair(Loc.Line, Loc.Column);
-      auto I = Result.find(Fn);
-      if (I == Result.end() || I->second > P) {
-        Result[Fn] = P;
-      }
+      auto [It, Inserted] = Result.try_emplace(Fn, P);
+      if (!Inserted && It->second > P)
+        It->second = P;
     }
   }
   return Result;

Original file line number	Diff line number	Diff line change
`@@ -961,10 +961,9 @@ static FunctionLocs resolveFunctions(const SymbolizedCoverage &Coverage,`
`961`	`961`	`continue;`
`962`	`962`
`963`	`963`	`auto P = std::make_pair(Loc.Line, Loc.Column);`
`964`		`- auto I = Result.find(Fn);`
`965`		`- if (I == Result.end() \|\| I->second > P) {`
`966`		`- Result[Fn] = P;`
`967`		`- }`
	`964`	`+ auto [It, Inserted] = Result.try_emplace(Fn, P);`
	`965`	`+ if (!Inserted && It->second > P)`
	`966`	`+ It->second = P;`
`968`	`967`	`}`
`969`	`968`	`}`
`970`	`969`	`return Result;`