[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

(cherry picked from commit fcfd3fd)

Author: ldrumm

clang/lib/CodeGen/CodeGenModule.cpp

@@ -6215,15 +6215,17 @@ 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(

clang/test/CodeGenOpenCL/sampler.cl

@@ -39,7 +39,7 @@ kernel void foo(sampler_t smp_par) {
   // Case 2b
   sampler_t smp = CLK_ADDRESS_CLAMP_TO_EDGE | CLK_NORMALIZED_COORDS_TRUE | CLK_FILTER_NEAREST;
   // CHECK: [[smp_ptr:%[A-Za-z0-9_\.]+]] = alloca %opencl.sampler_t addrspace(2)*
-  // CHECK: [[SAMP:%[0-9]+]] = call %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 19)
+  // CHECK: [[SAMP:%[0-9]+]] = call spir_func %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 19)
   // CHECK: store %opencl.sampler_t addrspace(2)* [[SAMP]], %opencl.sampler_t addrspace(2)** [[smp_ptr]]
 
   // Case 1b
@@ -56,12 +56,12 @@ kernel void foo(sampler_t smp_par) {
 
   // Case 1a/2a
   fnc4smp(glb_smp);
-  // CHECK: [[SAMP:%[0-9]+]] = call %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 35)
+  // CHECK: [[SAMP:%[0-9]+]] = call spir_func %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 35)
   // CHECK: call spir_func void [[FUNCNAME]](%opencl.sampler_t addrspace(2)* [[SAMP]])
 
   // Case 1a/2c
   fnc4smp(glb_smp_const);
-  // CHECK: [[SAMP:%[0-9]+]] = call %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 35)
+  // CHECK: [[SAMP:%[0-9]+]] = call spir_func %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 35)
   // CHECK: call spir_func void [[FUNCNAME]](%opencl.sampler_t addrspace(2)* [[SAMP]])
 
   // Case 1c
@@ -70,20 +70,20 @@ kernel void foo(sampler_t smp_par) {
   // CHECK: call spir_func void [[FUNCNAME]](%opencl.sampler_t addrspace(2)* [[SAMP]])
 
   fnc4smp(5);
-  // CHECK: [[SAMP:%[0-9]+]] = call %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 5)
+  // CHECK: [[SAMP:%[0-9]+]] = call spir_func %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 5)
   // CHECK: call spir_func void [[FUNCNAME]](%opencl.sampler_t addrspace(2)* [[SAMP]])
 
   const sampler_t const_smp = CLK_ADDRESS_CLAMP_TO_EDGE | CLK_NORMALIZED_COORDS_TRUE | CLK_FILTER_LINEAR;
   fnc4smp(const_smp);
-   // CHECK: [[CONST_SAMP:%[0-9]+]] = call %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 35)
+   // CHECK: [[CONST_SAMP:%[0-9]+]] = call spir_func %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 35)
   // CHECK: store %opencl.sampler_t addrspace(2)* [[CONST_SAMP]], %opencl.sampler_t addrspace(2)** [[CONST_SMP_PTR:%[a-zA-Z0-9]+]]
   fnc4smp(const_smp);
   // CHECK: [[SAMP:%[0-9]+]] = load %opencl.sampler_t addrspace(2)*, %opencl.sampler_t addrspace(2)** [[CONST_SMP_PTR]]
   // CHECK: call spir_func void [[FUNCNAME]](%opencl.sampler_t addrspace(2)* [[SAMP]])
 
   constant sampler_t constant_smp = CLK_ADDRESS_CLAMP_TO_EDGE | CLK_NORMALIZED_COORDS_TRUE | CLK_FILTER_LINEAR;
   fnc4smp(constant_smp);
-  // CHECK: [[SAMP:%[0-9]+]] = call %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 35)
+  // CHECK: [[SAMP:%[0-9]+]] = call spir_func %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 35)
   // CHECK: call spir_func void [[FUNCNAME]](%opencl.sampler_t addrspace(2)* [[SAMP]])
 
   // TODO: enable sampler initialization with non-constant integer.