[llvm] [Analysis] Avoid repeated hash lookups (NFC) (PR #128394)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-analysis

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/128394.diff


1 Files Affected:

- (modified) llvm/lib/Analysis/LoopAccessAnalysis.cpp (+4-5) 


``````````diff
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index a1d91de3bb788..5988e40c56100 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -1443,12 +1443,11 @@ void AccessAnalysis::processMemAccesses() {
                     UnderlyingObj->getType()->getPointerAddressSpace()))
               continue;
 
-            UnderlyingObjToAccessMap::iterator Prev =
-                ObjToLastAccess.find(UnderlyingObj);
-            if (Prev != ObjToLastAccess.end())
-              DepCands.unionSets(Access, Prev->second);
+            auto [It, Inserted] =
+                ObjToLastAccess.try_emplace(UnderlyingObj, Access);
+            if (!Inserted)
+              DepCands.unionSets(Access, It->second);
 
-            ObjToLastAccess[UnderlyingObj] = Access;
             LLVM_DEBUG(dbgs() << "  " << *UnderlyingObj << "\n");
           }
         }

``````````

</details>


https://github.com/llvm/llvm-project/pull/128394