[clang] [CodeGen] Don't use CreateRuntimeFunction() for intrinsics (PR #224329)

[Nikita Popov via cfe-commits]

https://github.com/nikic created https://github.com/llvm/llvm-project/pull/224329

These should just use getIntrinsic().

>From d143bb8966239ecbf6a8d00512192d0d85e9878f Mon Sep 17 00:00:00 2001
From: Nikita Popov <npopov at redhat.com>
Date: Thu, 17 Sep 2026 16:39:12 +0200
Subject: [PATCH 1/2] [CodeGen] Don't use CreateRuntimeFunction for intrinsics

These should just use getIntrinsic().
---
 clang/lib/CodeGen/CGCleanup.cpp   | 16 ++++------------
 clang/lib/CodeGen/CGException.cpp | 12 ++++--------
 2 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/clang/lib/CodeGen/CGCleanup.cpp b/clang/lib/CodeGen/CGCleanup.cpp
index 977f81a641ff3e..41a812ff59691e 100644
--- a/clang/lib/CodeGen/CGCleanup.cpp
+++ b/clang/lib/CodeGen/CGCleanup.cpp
@@ -1348,10 +1348,8 @@ static void EmitSehScope(CodeGenFunction &CGF,
 // Invoke a llvm.seh.scope.begin at the beginning of a CPP scope for -EHa
 void CodeGenFunction::EmitSehCppScopeBegin() {
   assert(getLangOpts().EHAsynch);
-  llvm::FunctionType *FTy =
-      llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
   llvm::FunctionCallee SehCppScope =
-      CGM.CreateRuntimeFunction(FTy, "llvm.seh.scope.begin");
+      CGM.getIntrinsic(llvm::Intrinsic::seh_scope_begin);
   EmitSehScope(*this, SehCppScope);
 }
 
@@ -1359,29 +1357,23 @@ void CodeGenFunction::EmitSehCppScopeBegin() {
 //   llvm.seh.scope.end is emitted before popCleanup, so it's "invoked"
 void CodeGenFunction::EmitSehCppScopeEnd() {
   assert(getLangOpts().EHAsynch);
-  llvm::FunctionType *FTy =
-      llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
   llvm::FunctionCallee SehCppScope =
-      CGM.CreateRuntimeFunction(FTy, "llvm.seh.scope.end");
+      CGM.getIntrinsic(llvm::Intrinsic::seh_scope_end);
   EmitSehScope(*this, SehCppScope);
 }
 
 // Invoke a llvm.seh.try.begin at the beginning of a SEH scope for -EHa
 void CodeGenFunction::EmitSehTryScopeBegin() {
   assert(getLangOpts().EHAsynch);
-  llvm::FunctionType *FTy =
-      llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
   llvm::FunctionCallee SehCppScope =
-      CGM.CreateRuntimeFunction(FTy, "llvm.seh.try.begin");
+      CGM.getIntrinsic(llvm::Intrinsic::seh_try_begin);
   EmitSehScope(*this, SehCppScope);
 }
 
 // Invoke a llvm.seh.try.end at the end of a SEH scope for -EHa
 void CodeGenFunction::EmitSehTryScopeEnd() {
   assert(getLangOpts().EHAsynch);
-  llvm::FunctionType *FTy =
-      llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
   llvm::FunctionCallee SehCppScope =
-      CGM.CreateRuntimeFunction(FTy, "llvm.seh.try.end");
+      CGM.getIntrinsic(llvm::Intrinsic::seh_try_end);
   EmitSehScope(*this, SehCppScope);
 }
diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index 2785c224cf4034..40f7476638c887 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -40,15 +40,11 @@ static llvm::FunctionCallee getFreeExceptionFn(CodeGenModule &CGM) {
 }
 
 static llvm::FunctionCallee getSehTryBeginFn(CodeGenModule &CGM) {
-  llvm::FunctionType *FTy =
-      llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
-  return CGM.CreateRuntimeFunction(FTy, "llvm.seh.try.begin");
+  return CGM.getIntrinsic(llvm::Intrinsic::seh_try_begin);
 }
 
 static llvm::FunctionCallee getSehTryEndFn(CodeGenModule &CGM) {
-  llvm::FunctionType *FTy =
-      llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
-  return CGM.CreateRuntimeFunction(FTy, "llvm.seh.try.end");
+  return CGM.getIntrinsic(llvm::Intrinsic::seh_try_end);
 }
 
 static llvm::FunctionCallee getUnexpectedFn(CodeGenModule &CGM) {
@@ -1683,7 +1679,7 @@ void CodeGenFunction::EmitSEHTryStmt(const SEHTryStmt &S) {
     llvm::BasicBlock *TryBB = nullptr;
     // IsEHa: emit an invoke to _seh_try_begin() runtime for -EHa
     if (getLangOpts().EHAsynch) {
-      EmitRuntimeCallOrInvoke(getSehTryBeginFn(CGM));
+      EmitCallOrInvoke(getSehTryBeginFn(CGM), {});
       if (SEHTryEpilogueStack.size() == 1) // outermost only
         TryBB = Builder.GetInsertBlock();
     }
@@ -2251,7 +2247,7 @@ void CodeGenFunction::ExitSEHTryStmt(const SEHTryStmt &S) {
   // IsEHa: emit an invoke _seh_try_end() to mark end of FT flow
   if (getLangOpts().EHAsynch && Builder.GetInsertBlock()) {
     llvm::FunctionCallee SehTryEnd = getSehTryEndFn(CGM);
-    EmitRuntimeCallOrInvoke(SehTryEnd);
+    EmitCallOrInvoke(SehTryEnd, {});
   }
 
   // Otherwise, we must have an __except block.

>From 4ed37858ed7f851a0f061d0f6956d699bd718e7d Mon Sep 17 00:00:00 2001
From: Nikita Popov <npopov at redhat.com>
Date: Thu, 17 Sep 2026 16:42:04 +0200
Subject: [PATCH 2/2] inline trivial functions

---
 clang/lib/CodeGen/CGException.cpp | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index 40f7476638c887..f06edde9739b4a 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -39,14 +39,6 @@ static llvm::FunctionCallee getFreeExceptionFn(CodeGenModule &CGM) {
   return CGM.CreateRuntimeFunction(FTy, "__cxa_free_exception");
 }
 
-static llvm::FunctionCallee getSehTryBeginFn(CodeGenModule &CGM) {
-  return CGM.getIntrinsic(llvm::Intrinsic::seh_try_begin);
-}
-
-static llvm::FunctionCallee getSehTryEndFn(CodeGenModule &CGM) {
-  return CGM.getIntrinsic(llvm::Intrinsic::seh_try_end);
-}
-
 static llvm::FunctionCallee getUnexpectedFn(CodeGenModule &CGM) {
   // void __cxa_call_unexpected(void *thrown_exception);
 
@@ -1679,7 +1671,7 @@ void CodeGenFunction::EmitSEHTryStmt(const SEHTryStmt &S) {
     llvm::BasicBlock *TryBB = nullptr;
     // IsEHa: emit an invoke to _seh_try_begin() runtime for -EHa
     if (getLangOpts().EHAsynch) {
-      EmitCallOrInvoke(getSehTryBeginFn(CGM), {});
+      EmitCallOrInvoke(CGM.getIntrinsic(llvm::Intrinsic::seh_try_begin), {});
       if (SEHTryEpilogueStack.size() == 1) // outermost only
         TryBB = Builder.GetInsertBlock();
     }
@@ -2246,8 +2238,7 @@ void CodeGenFunction::ExitSEHTryStmt(const SEHTryStmt &S) {
 
   // IsEHa: emit an invoke _seh_try_end() to mark end of FT flow
   if (getLangOpts().EHAsynch && Builder.GetInsertBlock()) {
-    llvm::FunctionCallee SehTryEnd = getSehTryEndFn(CGM);
-    EmitCallOrInvoke(SehTryEnd, {});
+    EmitCallOrInvoke(CGM.getIntrinsic(llvm::Intrinsic::seh_try_end), {});
   }
 
   // Otherwise, we must have an __except block.