[SPIR-V] Add basic support for byval/byref ptr arguments

Author: michalpaszkowski

llvm/lib/Target/SPIRV/SPIRVCallLowering.cpp

@@ -165,13 +165,25 @@ static SPIRVType *getArgSPIRVType(const Function &F, unsigned ArgIdx,
   if (!OriginalArgType->isPointerTy())
     return GR->getOrCreateSPIRVType(OriginalArgType, MIRBuilder, ArgAccessQual);
 
-  // In case OriginalArgType is of pointer type, there are two possibilities:
-  // 1) This is an OpenCL/SPIR-V builtin type if there is spv_assign_type
+  // In case OriginalArgType is of pointer type, there are three possibilities:
+  // 1) This is a pointer of an LLVM IR element type, passed byval/byref.
+  // 2) This is an OpenCL/SPIR-V builtin type if there is spv_assign_type
   // intrinsic assigning a TargetExtType.
-  // 2) This is a pointer, try to retrieve pointer element type from a
+  // 3) This is a pointer, try to retrieve pointer element type from a
   // spv_assign_ptr_type intrinsic or otherwise use default pointer element
   // type.
-  for (auto User : F.getArg(ArgIdx)->users()) {
+  Argument *Arg = F.getArg(ArgIdx);
+  if (Arg->hasByValAttr() || Arg->hasByRefAttr()) {
+    Type *ByValRefType = Arg->hasByValAttr() ? Arg->getParamByValType()
+                                             : Arg->getParamByRefType();
+    SPIRVType *ElementType = GR->getOrCreateSPIRVType(ByValRefType, MIRBuilder);
+    return GR->getOrCreateSPIRVPointerType(
+        ElementType, MIRBuilder,
+        addressSpaceToStorageClass(Arg->getType()->getPointerAddressSpace(),
+                                   ST));
+  }
+
+  for (auto User : Arg->users()) {
     auto *II = dyn_cast<IntrinsicInst>(User);
     // Check if this is spv_assign_type assigning OpenCL/SPIR-V builtin type.
     if (II && II->getIntrinsicID() == Intrinsic::spv_assign_type) {

llvm/test/CodeGen/SPIRV/pointers/ptr-argument-byref.ll

@@ -0,0 +1,24 @@
+; RUN: llc -O0 -mtriple=spirv64-unknown-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+
+target triple = "spirv64-unknown-unknown"
+
+; CHECK-DAG: %[[#VOID:]] = OpTypeVoid
+; CHECK-DAG: %[[#INT32:]] = OpTypeInt 32 0
+; CHECK-DAG: %[[#STRUCT1:]] = OpTypeStruct %[[#INT32]]
+; CHECK-DAG: %[[#CONST:]] = OpConstant %[[#INT32]] 7
+; CHECK-DAG: %[[#ARRAY:]] = OpTypeArray %[[#STRUCT1]] %[[#CONST]]
+; CHECK-DAG: %[[#STRUCT2:]] = OpTypeStruct %[[#ARRAY]]
+; CHECK-DAG: %[[#PTR:]] = OpTypePointer Function %[[#STRUCT2]]
+
+; CHECK:  %[[#FUNC:]] = OpTypeFunction %[[#VOID]] %[[#PTR]]
+; CHECK:  %[[#]] = OpFunction %[[#VOID]] None %[[#FUNC]]
+; CHECK:  %[[#]] = OpFunctionParameter %[[#PTR]]
+
+%struct.S = type { i32 }
+%struct.__wrapper_class = type { [7 x %struct.S] }
+
+define spir_kernel void @foo(ptr noundef byref(%struct.__wrapper_class) align 4 %_arg_Arr) {
+entry:
+  ret void
+}

llvm/test/CodeGen/SPIRV/pointers/ptr-argument-byval.ll

@@ -0,0 +1,22 @@
+; RUN: llc -O0 -mtriple=spirv64-unknown-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+
+; CHECK-DAG: %[[#VOID:]] = OpTypeVoid
+; CHECK-DAG: %[[#INT32:]] = OpTypeInt 32 0
+; CHECK-DAG: %[[#STRUCT1:]] = OpTypeStruct %[[#INT32]]
+; CHECK-DAG: %[[#CONST:]] = OpConstant %[[#INT32]] 7
+; CHECK-DAG: %[[#ARRAY:]] = OpTypeArray %[[#STRUCT1]] %[[#CONST]]
+; CHECK-DAG: %[[#STRUCT2:]] = OpTypeStruct %[[#ARRAY]]
+; CHECK-DAG: %[[#PTR:]] = OpTypePointer Function %[[#STRUCT2]]
+
+; CHECK:  %[[#FUNC:]] = OpTypeFunction %[[#VOID]] %[[#PTR]]
+; CHECK:  %[[#]] = OpFunction %[[#VOID]] None %[[#FUNC]]
+; CHECK:  %[[#]] = OpFunctionParameter %[[#PTR]]
+
+%struct.S = type { i32 }
+%struct.__wrapper_class = type { [7 x %struct.S] }
+
+define spir_kernel void @foo(ptr noundef byval(%struct.__wrapper_class) align 4 %_arg_Arr) {
+entry:
+  ret void
+}