[ctx_prof] Simplify ingestContext (NFC)

[kazutakahirata]

try_emplace can default-construct the value, so:

try_emplace(CSId, CallTargetMapTy())
try_emplace(CSId)

are equivalent to each other. We can further simplify the function
using the fact that Map.try_emplace(Key).first->second is the same as
Map[Key].

[llvmbot]

@llvm/pr-subscribers-pgo

Author: Kazu Hirata (kazutakahirata)

Changes

try_emplace can default-construct the value, so:

try_emplace(CSId, CallTargetMapTy())
try_emplace(CSId)

are equivalent to each other. We can further simplify the function
using the fact that Map.try_emplace(Key).first->second is the same as
Map[Key].

---

Full diff: https://github.com/llvm/llvm-project/pull/109902.diff

1 Files Affected:

• (modified) llvm/include/llvm/ProfileData/PGOCtxProfReader.h (+1-2)

diff --git a/llvm/include/llvm/ProfileData/PGOCtxProfReader.h b/llvm/include/llvm/ProfileData/PGOCtxProfReader.h
index beda07d7b8286c..a00c21ddc7d7a1 100644
--- a/llvm/include/llvm/ProfileData/PGOCtxProfReader.h
+++ b/llvm/include/llvm/ProfileData/PGOCtxProfReader.h
@@ -68,8 +68,7 @@ class PGOCtxProfContext final {
   CallsiteMapTy &callsites() { return Callsites; }
 
   void ingestContext(uint32_t CSId, PGOCtxProfContext &&Other) {
-    auto [Iter, _] = callsites().try_emplace(CSId, CallTargetMapTy());
-    Iter->second.emplace(Other.guid(), std::move(Other));
+    callsites()[CSId].emplace(Other.guid(), std::move(Other));
   }
 
   void ingestAllContexts(uint32_t CSId, CallTargetMapTy &&Other) {