[llvm] [InlineCost] Use a const reference (NFC) (PR #95687)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-analysis

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>

The use of a const reference here saves 0.18% of heap allocations
during the compilation of a large preprocessed file, namely
X86ISelLowering.cpp, for the X86 target.

Note that GetTLI returns a const reference, so we don't have to worry
about a dangling reference.

---
Full diff: https://github.com/llvm/llvm-project/pull/95687.diff


1 Files Affected:

- (modified) llvm/lib/Analysis/InlineCost.cpp (+1-1) 


``````````diff
diff --git a/llvm/lib/Analysis/InlineCost.cpp b/llvm/lib/Analysis/InlineCost.cpp
index f5b17dca49735..c3aeac7492804 100644
--- a/llvm/lib/Analysis/InlineCost.cpp
+++ b/llvm/lib/Analysis/InlineCost.cpp
@@ -2887,7 +2887,7 @@ static bool functionsHaveCompatibleAttributes(
   // caches the most recently created TLI in the TargetLibraryInfoWrapperPass
   // object, and always returns the same object (which is overwritten on each
   // GetTLI call). Therefore we copy the first result.
-  auto CalleeTLI = GetTLI(*Callee);
+  const auto &CalleeTLI = GetTLI(*Callee);
   return (IgnoreTTIInlineCompatible ||
           TTI.areInlineCompatible(Caller, Callee)) &&
          GetTLI(*Caller).areInlineCompatible(CalleeTLI,

``````````

</details>


https://github.com/llvm/llvm-project/pull/95687