[llvm] [PassManager] Simplify code with DenseMap::try_emplace (NFC) (PR #140402)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-ir

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>

We can simplify the code with DenseMap::try_emplace and structured
binding.  Note that DenseMap::try_emplace default-constructs the value
if omitted.


---
Full diff: https://github.com/llvm/llvm-project/pull/140402.diff


1 Files Affected:

- (modified) llvm/include/llvm/IR/PassManagerImpl.h (+1-4) 


``````````diff
diff --git a/llvm/include/llvm/IR/PassManagerImpl.h b/llvm/include/llvm/IR/PassManagerImpl.h
index 67e3fbe4f3068..55f504c921852 100644
--- a/llvm/include/llvm/IR/PassManagerImpl.h
+++ b/llvm/include/llvm/IR/PassManagerImpl.h
@@ -136,10 +136,7 @@ template <typename IRUnitT, typename... ExtraArgTs>
 inline typename AnalysisManager<IRUnitT, ExtraArgTs...>::ResultConceptT &
 AnalysisManager<IRUnitT, ExtraArgTs...>::getResultImpl(
     AnalysisKey *ID, IRUnitT &IR, ExtraArgTs... ExtraArgs) {
-  typename AnalysisResultMapT::iterator RI;
-  bool Inserted;
-  std::tie(RI, Inserted) = AnalysisResults.insert(std::make_pair(
-      std::make_pair(ID, &IR), typename AnalysisResultListT::iterator()));
+  auto [RI, Inserted] = AnalysisResults.try_emplace(std::make_pair(ID, &IR));
 
   // If we don't have a cached result for this function, look up the pass and
   // run it to produce a result, which we then add to the cache.

``````````

</details>


https://github.com/llvm/llvm-project/pull/140402