[llvm] [ARM] Avoid repeated hash lookups (NFC) (PR #107356)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-arm

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/107356.diff


1 Files Affected:

- (modified) llvm/lib/Target/ARM/ARMMachineFunctionInfo.h (+3-7) 


``````````diff
diff --git a/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h b/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h
index b9ff3a08f998f6..54bf5fffd3942c 100644
--- a/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h
+++ b/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h
@@ -254,13 +254,9 @@ class ARMFunctionInfo : public MachineFunctionInfo {
       return -1U;
   }
 
-  DenseMap<const MachineBasicBlock*, unsigned>::iterator getCoalescedWeight(
-                                                  MachineBasicBlock* MBB) {
-    auto It = CoalescedWeights.find(MBB);
-    if (It == CoalescedWeights.end()) {
-      It = CoalescedWeights.insert(std::make_pair(MBB, 0)).first;
-    }
-    return It;
+  DenseMap<const MachineBasicBlock *, unsigned>::iterator
+  getCoalescedWeight(MachineBasicBlock *MBB) {
+    return CoalescedWeights.try_emplace(MBB, 0).first;
   }
 
   /// Indicate to the backend that \c GV has had its storage changed to inside

``````````

</details>


https://github.com/llvm/llvm-project/pull/107356