[CodeGen] Avoid repeated hash lookups (NFC)

[kazutakahirata]

No description provided.

[llvmbot]

@llvm/pr-subscribers-debuginfo

Author: Kazu Hirata (kazutakahirata)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/131495.diff

1 Files Affected:

• (modified) llvm/lib/CodeGen/MachineDebugify.cpp (+5-2)

diff --git a/llvm/lib/CodeGen/MachineDebugify.cpp b/llvm/lib/CodeGen/MachineDebugify.cpp
index bffdd51bfbca7..d0e325824c89a 100644
--- a/llvm/lib/CodeGen/MachineDebugify.cpp
+++ b/llvm/lib/CodeGen/MachineDebugify.cpp
@@ -123,10 +123,13 @@ bool applyDebugifyMetadataToMachineFunction(MachineModuleInfo &MMI,
 
       // Find a suitable local variable for the DBG_VALUE.
       unsigned Line = MI.getDebugLoc().getLine();
-      if (!Line2Var.count(Line))
+      auto It = Line2Var.find(Line);
+      if (It == Line2Var.end()) {
         Line = EarliestDVI ? EarliestDVI->getDebugLoc().getLine()
                            : EarliestDVR->getDebugLoc().getLine();
-      DILocalVariable *LocalVar = Line2Var[Line];
+        It = Line2Var.try_emplace(Line).first;
+      }
+      DILocalVariable *LocalVar = It->second;
       assert(LocalVar && "No variable for current line?");
       VarSet.insert(LocalVar);