[OpenCL] Do not generate "kernel_arg_type_qual" metadata for non-pointer args

[echuraev]

Summary

"kernel_arg_type_qual" metadata should contain const/volatile/restrict
tags only for pointer types to match the corresponding requirement of
the OpenCL specification.

OpenCL 2.0 spec 5.9.3 Kernel Object Queries:

CL_KERNEL_ARG_TYPE_VOLATILE is returned if the argument is a pointer
and the referenced type is declared with the volatile qualifier.
[...]
Similarly, CL_KERNEL_ARG_TYPE_CONST is returned if the argument is a
pointer and the referenced type is declared with the restrict or const
qualifier.
[...]
CL_KERNEL_ARG_TYPE_RESTRICT will be returned if the pointer type is
marked restrict.

[Anastasia]

test/CodeGenOpenCL/kernel-arg-info.cl

66

Could we modify the test to check that const and volatile are added for the pointers though?

[echuraev]

test/CodeGenOpenCL/kernel-arg-info.cl

66

Added test case only for volatile pointer because const is checked in the Z argument of foo function.

[Anastasia]

LGTM!

test/CodeGenOpenCL/kernel-arg-info.cl

66

I think it would still be nice to add an argument with explicit const because the current test doesn't have it explicitly.

lib/CodeGen/CodeGenFunction.cpp

if (ty->isPointerType()) {
 
       // Turn "unsigned type" to "utype"
       pos = baseTypeName.find("unsigned");
       if (pos != std::string::npos)
         baseTypeName.erase(pos+1, 8);
 
       argBaseTypeNames.push_back(llvm::MDString::get(Context, baseTypeName));
 
-      // Get argument type qualifiers:
-      if (ty.isConstQualified())
-        typeQuals = "const";
-      if (ty.isVolatileQualified())
-        typeQuals += typeQuals.empty() ? "volatile" : " volatile";
       if (isPipe)
         typeQuals = "pipe";
     }
 
     argTypeQuals.push_back(llvm::MDString::get(Context, typeQuals));
 
     // Get image and pipe access qualifier:
     if (ty->isImageType()|| ty->isPipeType()) {

test/CodeGenOpenCL/kernel-arg-info.cl

 // RUN: %clang_cc1 %s -cl-std=CL2.0 -emit-llvm -o - -triple spir-unknown-unknown | FileCheck %s
 // RUN: %clang_cc1 %s -cl-std=CL2.0 -emit-llvm -o - -triple spir-unknown-unknown -cl-kernel-arg-info | FileCheck %s -check-prefix ARGINFO
 
 kernel void foo(__global int * restrict X, const int Y, 
-                volatile int anotherArg, __constant float * restrict Z) {
+                volatile int anotherArg, __constant float * restrict Z,
+                __global volatile int * V, __global const int * C) {
   *X = Y + anotherArg;
 }
 // CHECK: define spir_kernel void @foo{{[^!]+}}
 // CHECK: !kernel_arg_addr_space ![[MD11:[0-9]+]]
 // CHECK: !kernel_arg_access_qual ![[MD12:[0-9]+]]
 // CHECK: !kernel_arg_type ![[MD13:[0-9]+]]
 // CHECK: !kernel_arg_base_type ![[MD13]]
 // CHECK: !kernel_arg_type_qual ![[MD14:[0-9]+]]

 // CHECK: !kernel_arg_addr_space ![[MD41:[0-9]+]]
 // CHECK: !kernel_arg_access_qual ![[MD51:[0-9]+]]
 // CHECK: !kernel_arg_type ![[MD52:[0-9]+]]
 // CHECK: !kernel_arg_base_type ![[MD53:[0-9]+]]
 // CHECK: !kernel_arg_type_qual ![[MD45]]
 // CHECK-NOT: !kernel_arg_name
 // ARGINFO: !kernel_arg_name ![[MD54:[0-9]+]]
 
-// CHECK: ![[MD11]] = !{i32 1, i32 0, i32 0, i32 2}
-// CHECK: ![[MD12]] = !{!"none", !"none", !"none", !"none"}
-// CHECK: ![[MD13]] = !{!"int*", !"int", !"int", !"float*"}
-// CHECK: ![[MD14]] = !{!"restrict", !"const", !"volatile", !"restrict const"}
-// ARGINFO: ![[MD15]] = !{!"X", !"Y", !"anotherArg", !"Z"}
+// CHECK: ![[MD11]] = !{i32 1, i32 0, i32 0, i32 2, i32 1, i32 1}
+// CHECK: ![[MD12]] = !{!"none", !"none", !"none", !"none", !"none", !"none"}
+// CHECK: ![[MD13]] = !{!"int*", !"int", !"int", !"float*", !"int*", !"int*"}
+// CHECK: ![[MD14]] = !{!"restrict", !"", !"", !"restrict const", !"volatile", !"const"}
+// ARGINFO: ![[MD15]] = !{!"X", !"Y", !"anotherArg", !"Z", !"V", !"C"}
 // CHECK: ![[MD21]] = !{i32 1, i32 1, i32 1, i32 1}
 // CHECK: ![[MD22]] = !{!"read_only", !"read_only", !"write_only", !"read_write"}
 // CHECK: ![[MD23]] = !{!"image1d_t", !"image2d_t", !"image2d_array_t", !"image1d_t"}
 // CHECK: ![[MD24]] = !{!"", !"", !"", !""}
 // ARGINFO: ![[MD25]] = !{!"img1", !"img2", !"img3", !"img4"}
 // CHECK: ![[MD31]] = !{i32 1}
 // CHECK: ![[MD32]] = !{!"none"}
 // CHECK: ![[MD33]] = !{!"half*"}