[OpenCL] Respect calling convention for builtin

`__translate_sampler_initializer` has a calling convention of
`spir_func`, but clang generated calls to it using the default CC.

Instruction Combining was lowering these mismatching calling conventions
to `store i1* undef` which itself was subsequently lowered to a trap
instruction by simplifyCFG resulting in runtime `SIGILL`

There are arguably two bugs here: but whether there's any wisdom in
converting an obviously invalid call into a runtime crash over aborting
with a sensible error message will require further discussion. So for
now it's enough to set the right calling convention on the runtime
helper.

Reviewed By: svenh, bader

Differential Revision: https://reviews.llvm.org/D98411

1 files changed, 7 insertions, 5 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 250946bd56dd..75854f69b110 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -6258,15 +6258,17 @@ llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
 
   return *SanStats;
 }
+
 llvm::Value *
 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
                                                   CodeGenFunction &CGF) {
   llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
-  auto SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
-  auto FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
-  return CGF.Builder.CreateCall(CreateRuntimeFunction(FTy,
-                                "__translate_sampler_initializer"),
-                                {C});
+  auto *SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
+  auto *FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
+  auto *Call = CGF.Builder.CreateCall(
+      CreateRuntimeFunction(FTy, "__translate_sampler_initializer"), {C});
+  Call->setCallingConv(Call->getCalledFunction()->getCallingConv());
+  return Call;
 }
 
 CharUnits CodeGenModule::getNaturalPointeeTypeAlignment(