[ProfileData] Avoid repeated hash lookups (NFC)

[kazutakahirata]

No description provided.

[llvmbot]

@llvm/pr-subscribers-pgo

Author: Kazu Hirata (kazutakahirata)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/110619.diff

1 Files Affected:

• (modified) llvm/lib/ProfileData/Coverage/CoverageMapping.cpp (+4-7)

diff --git a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
index 18643c6b44485e..c713371da81e40 100644
--- a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
+++ b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
@@ -49,13 +49,10 @@ using namespace coverage;
 #define DEBUG_TYPE "coverage-mapping"
 
 Counter CounterExpressionBuilder::get(const CounterExpression &E) {
-  auto It = ExpressionIndices.find(E);
-  if (It != ExpressionIndices.end())
-    return Counter::getExpression(It->second);
-  unsigned I = Expressions.size();
-  Expressions.push_back(E);
-  ExpressionIndices[E] = I;
-  return Counter::getExpression(I);
+  auto [It, Inserted] = ExpressionIndices.try_emplace(E, Expressions.size());
+  if (Inserted)
+    Expressions.push_back(E);
+  return Counter::getExpression(It->second);
 }
 
 void CounterExpressionBuilder::extractTerms(Counter C, int Factor,