[OpenCL] Fix sampler initialization for C++ mode

[neil.hickey]

Summary

Sampler initialization from integer literal was broken in C++ mode for OpenCL. Fixing to allow functions that take a sampler to take an integer and for samplers to be initialized to integer values.

[Anastasia]

LGTM! Thanks!

I expect the example from the bug is going to compile now: https://bugs.llvm.org/show_bug.cgi?id=41009

Can you please close the bug after the commit.

lib/Sema/SemaOverload.cpp

1854

My only comment here is that we might be able to remove the same logic where it works just for C. But it can be done in a separate patch too.

1856

No idea why we are adding separate conversion kind for event and queue types. Again, it might be something we can simplify above.

lib/Sema/SemaInit.cpp

if (const ArrayType *DestAT = Context.getAsArrayType(DestType)) {
     return;
   }
 
   // Determine whether we should consider writeback conversions for
   // Objective-C ARC.
   bool allowObjCWritebackConversion = S.getLangOpts().ObjCAutoRefCount &&
          Entity.isParameterKind();
 
+  if (TryOCLSamplerInitialization(S, *this, DestType, Initializer))
+    return;
+
   // We're at the end of the line for C: it's either a write-back conversion
   // or it's a C assignment. There's no need to check anything else.
   if (!S.getLangOpts().CPlusPlus) {
     // If allowed, check whether this is an Objective-C writeback conversion.
     if (allowObjCWritebackConversion &&
         tryObjCWritebackConversion(S, *this, Entity, Initializer)) {
       return;
     }
 
-    if (TryOCLSamplerInitialization(S, *this, DestType, Initializer))
-      return;
-
     if (TryOCLZeroOpaqueTypeInitialization(S, *this, DestType, Initializer))
       return;
 
     // Handle initialization in C
     AddCAssignmentStep(DestType);
     MaybeProduceObjCObject(S, *this, Entity);
     return;
   }

lib/Sema/SemaOverload.cpp

return true;
              From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
     SCS.Second = ICK_Zero_Event_Conversion;
     FromType = ToType;
   } else if (ToType->isQueueT() &&
              From->isIntegerConstantExpr(S.getASTContext()) &&
              (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
     SCS.Second = ICK_Zero_Queue_Conversion;
     FromType = ToType;
+  } else if (ToType->isSamplerT() &&
+             From->isIntegerConstantExpr(S.getASTContext())) {
+    SCS.Second = ICK_Compatible_Conversion;
+    FromType = ToType;
   } else {
     // No second conversion required.
     SCS.Second = ICK_Identity;
   }
   SCS.setToType(1, FromType);
 
   // The third conversion can be a function pointer conversion or a
   // qualification conversion (C++ [conv.fctptr], [conv.qual]).

test/CodeGenOpenCL/sampler.cl

 // RUN: %clang_cc1 %s -emit-llvm -triple spir-unknown-unknown -o - -O0 | FileCheck %s
 // RUN: %clang_cc1 %s -cl-std=CL2.0 -emit-llvm -triple spir-unknown-unknown -o - -O0 | FileCheck %s
+// RUN: %clang_cc1 %s -cl-std=c++ -emit-llvm -triple spir-unknown-unknown -o - -O0 | FileCheck %s
 //
 // This test covers 5 cases of sampler initialzation:
 //   1. function argument passing
 //      1a. argument is a file-scope variable
 //      1b. argument is a function-scope variable
 //      1c. argument is one of caller function's parameters
 //   2. variable initialization
 //      2a. initializing a file-scope variable with constant addr space qualifier

 
 // Case 2c
 const sampler_t glb_smp_const = CLK_ADDRESS_CLAMP_TO_EDGE | CLK_NORMALIZED_COORDS_TRUE | CLK_FILTER_LINEAR;
 // CHECK-NOT: glb_smp_const
 
 int get_sampler_initializer(void);
 
 void fnc4smp(sampler_t s) {}
-// CHECK: define spir_func void @fnc4smp(%opencl.sampler_t addrspace(2)* %
+// CHECK: define spir_func void [[FUNCNAME:@.*fnc4smp.*]](%opencl.sampler_t addrspace(2)* %
 
 kernel void foo(sampler_t smp_par) {
   // CHECK-LABEL: define spir_kernel void @foo(%opencl.sampler_t addrspace(2)* %smp_par)
   // CHECK: [[smp_par_ptr:%[A-Za-z0-9_\.]+]] = alloca %opencl.sampler_t addrspace(2)*
 
   // 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: store %opencl.sampler_t addrspace(2)* [[SAMP]], %opencl.sampler_t addrspace(2)** [[smp_ptr]]
 
   // Case 1b
   fnc4smp(smp);
   // CHECK-NOT: call %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 19)
   // CHECK: [[SAMP:%[0-9]+]] = load %opencl.sampler_t addrspace(2)*, %opencl.sampler_t addrspace(2)** [[smp_ptr]]
-  // CHECK: call spir_func void @fnc4smp(%opencl.sampler_t addrspace(2)* [[SAMP]])
+  // CHECK: call spir_func void [[FUNCNAME]](%opencl.sampler_t addrspace(2)* [[SAMP]])
 
   // Case 1b
   fnc4smp(smp);
   // CHECK-NOT: call %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 19)
   // CHECK: [[SAMP:%[0-9]+]] = load %opencl.sampler_t addrspace(2)*, %opencl.sampler_t addrspace(2)** [[smp_ptr]]
-  // CHECK: call spir_func void @fnc4smp(%opencl.sampler_t addrspace(2)* [[SAMP]])
+  // CHECK: call spir_func void [[FUNCNAME]](%opencl.sampler_t addrspace(2)* [[SAMP]])
 
   // Case 1a/2a
   fnc4smp(glb_smp);
   // CHECK: [[SAMP:%[0-9]+]] = call %opencl.sampler_t addrspace(2)* @__translate_sampler_initializer(i32 35)
-  // CHECK: call spir_func void @fnc4smp(%opencl.sampler_t addrspace(2)* [[SAMP]])
+  // 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: call spir_func void @fnc4smp(%opencl.sampler_t addrspace(2)* [[SAMP]])
+  // CHECK: call spir_func void [[FUNCNAME]](%opencl.sampler_t addrspace(2)* [[SAMP]])
 
   // Case 1c
   fnc4smp(smp_par);
   // CHECK: [[SAMP:%[0-9]+]] = load %opencl.sampler_t addrspace(2)*, %opencl.sampler_t addrspace(2)** [[smp_par_ptr]]
-  // CHECK: call spir_func void @fnc4smp(%opencl.sampler_t addrspace(2)* [[SAMP]])
+  // 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: call spir_func void @fnc4smp(%opencl.sampler_t addrspace(2)* [[SAMP]])
+  // 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: 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 @fnc4smp(%opencl.sampler_t addrspace(2)* [[SAMP]])
+  // 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: call spir_func void @fnc4smp(%opencl.sampler_t addrspace(2)* [[SAMP]])
+  // CHECK: call spir_func void [[FUNCNAME]](%opencl.sampler_t addrspace(2)* [[SAMP]])
 
   // TODO: enable sampler initialization with non-constant integer.
   //const sampler_t const_smp_func_init = get_sampler_initializer();
 }