[llvm] [TargetParser] Avoid repeated hash lookups (NFC) (PR #131555)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-risc-v

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/131555.diff


1 Files Affected:

- (modified) llvm/lib/TargetParser/RISCVISAInfo.cpp (+3-2) 


``````````diff
diff --git a/llvm/lib/TargetParser/RISCVISAInfo.cpp b/llvm/lib/TargetParser/RISCVISAInfo.cpp
index ecd397f451c79..f7b487688d352 100644
--- a/llvm/lib/TargetParser/RISCVISAInfo.cpp
+++ b/llvm/lib/TargetParser/RISCVISAInfo.cpp
@@ -839,10 +839,11 @@ void RISCVISAInfo::updateImplication() {
     std::for_each(Range.first, Range.second,
                   [&](const ImpliedExtsEntry &Implied) {
                     const char *ImpliedExt = Implied.ImpliedExt;
-                    if (Exts.count(ImpliedExt))
+                    auto [It, Inserted] = Exts.try_emplace(ImpliedExt);
+                    if (!Inserted)
                       return;
                     auto Version = findDefaultVersion(ImpliedExt);
-                    Exts[ImpliedExt] = *Version;
+                    It->second = *Version;
                     WorkList.push_back(ImpliedExt);
                   });
   }

``````````

</details>


https://github.com/llvm/llvm-project/pull/131555