[llvm] [ORC] Use SmallVector/SmallString for small hot paths (PR #148379)

[Bogdan Vetrenko via llvm-commits]

https://github.com/bv2k4 updated https://github.com/llvm/llvm-project/pull/148379

>From 0623a934156c98909d762051bc3e52a55b80318f Mon Sep 17 00:00:00 2001
From: Bogdan Vetrenko <b.vetrenko at yandex.ru>
Date: Sat, 12 Jul 2025 18:35:45 +0300
Subject: [PATCH] [ORC] Use SmallVector/SmallString for small hot paths

---
 llvm/lib/ExecutionEngine/Orc/LLJIT.cpp | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
index 67bb7dd8ad08f..f36760ee4433d 100644
--- a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
@@ -8,6 +8,7 @@
 
 #include "llvm/ExecutionEngine/Orc/LLJIT.h"
 
+#include "llvm/ADT/SmallString.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Config/llvm-config.h" // for LLVM_ENABLE_THREADS
 #include "llvm/ExecutionEngine/Orc/COFFPlatform.h"
@@ -331,7 +332,7 @@ class GenericLLVMIRPlatformSupport : public LLJIT::PlatformSupport {
         Initializers.push_back(KV.second.getAddress());
     }
 
-    return Initializers;
+    return std::vector<ExecutorAddr>(Initializers.begin(), Initializers.end());;
   }
 
   Expected<std::vector<ExecutorAddr>> getDeinitializers(JITDylib &JD) {
@@ -392,7 +393,7 @@ class GenericLLVMIRPlatformSupport : public LLJIT::PlatformSupport {
           DeInitializers.push_back(KV.second.getAddress());
     }
 
-    return DeInitializers;
+    return std::vector<ExecutorAddr>(DeInitializers.begin(), DeInitializers.end());;
   }
 
   /// Issue lookups for all init symbols required to initialize JD (and any
@@ -518,13 +519,10 @@ GlobalCtorDtorScraper::operator()(ThreadSafeModule TSM,
       // If there's no llvm.global_c/dtor or it's just a decl then skip.
       if (!GlobalCOrDtors || GlobalCOrDtors->isDeclaration())
         return Error::success();
-      std::string InitOrDeInitFunctionName;
-      if (isCtor)
-        raw_string_ostream(InitOrDeInitFunctionName)
-            << InitFunctionPrefix << M.getModuleIdentifier();
-      else
-        raw_string_ostream(InitOrDeInitFunctionName)
-            << DeInitFunctionPrefix << M.getModuleIdentifier();
+      SmallString<64> InitOrDeInitFunctionName;
+      raw_svector_ostream(InitOrDeInitFunctionName)
+          << (isCtor ? InitFunctionPrefix : DeInitFunctionPrefix)
+          << M.getModuleIdentifier();
 
       MangleAndInterner Mangle(PS.getExecutionSession(), M.getDataLayout());
       auto InternedInitOrDeInitName = Mangle(InitOrDeInitFunctionName);
@@ -536,7 +534,7 @@ GlobalCtorDtorScraper::operator()(ThreadSafeModule TSM,
           FunctionType::get(Type::getVoidTy(Ctx), {}, false),
           GlobalValue::ExternalLinkage, InitOrDeInitFunctionName, &M);
       InitOrDeInitFunc->setVisibility(GlobalValue::HiddenVisibility);
-      std::vector<std::pair<Function *, unsigned>> InitsOrDeInits;
+      SmallVector<std::pair<Function *, unsigned>, 8> InitsOrDeInits;
       auto COrDtors = isCtor ? getConstructors(M) : getDestructors(M);
 
       for (auto E : COrDtors)