[llvm] [DebugInfo] Avoid repeated hash lookups (NFC) (PR #112298)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-debuginfo

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/112298.diff


1 Files Affected:

- (modified) llvm/lib/DebugInfo/PDB/Native/SymbolCache.cpp (+3-3) 


``````````diff
diff --git a/llvm/lib/DebugInfo/PDB/Native/SymbolCache.cpp b/llvm/lib/DebugInfo/PDB/Native/SymbolCache.cpp
index 1a31aa206dfcc6..463b9ebe3cbff5 100644
--- a/llvm/lib/DebugInfo/PDB/Native/SymbolCache.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/SymbolCache.cpp
@@ -447,11 +447,11 @@ SymbolCache::findPublicSymbolBySectOffset(uint32_t Sect, uint32_t Offset) {
 std::vector<SymbolCache::LineTableEntry>
 SymbolCache::findLineTable(uint16_t Modi) const {
   // Check if this module has already been added.
-  auto LineTableIter = LineTable.find(Modi);
-  if (LineTableIter != LineTable.end())
+  auto [LineTableIter, Inserted] = LineTable.try_emplace(Modi);
+  if (!Inserted)
     return LineTableIter->second;
 
-  std::vector<LineTableEntry> &ModuleLineTable = LineTable[Modi];
+  std::vector<LineTableEntry> &ModuleLineTable = LineTableIter->second;
 
   // If there is an error or there are no lines, just return the
   // empty vector.

``````````

</details>


https://github.com/llvm/llvm-project/pull/112298