[spirv] Handles rvalue as implicit object argument of vk::BufferPointer::Get(). (microsoft#7313)

[spirv] Handles rvalue as implicit object argument of
vk::BufferPointer::Get().
Fixes microsoft#7302.

Author: danbrown-amd

tools/clang/lib/SPIRV/SpirvEmitter.cpp

@@ -10932,6 +10932,12 @@ SpirvInstruction *SpirvEmitter::processIntrinsicGetBufferContents(
   SpirvInstruction *bufferPointer = doExpr(obj);
   if (!bufferPointer)
     return nullptr;
+  if (bufferPointer->isRValue()) {
+    bufferPointer->setRValue(false);
+    bufferPointer->setStorageClass(spv::StorageClass::PhysicalStorageBuffer);
+    return bufferPointer;
+  }
+
   unsigned align = hlsl::GetVKBufferPointerAlignment(obj->getType());
   lowerTypeVisitor.visitInstruction(bufferPointer);
 

tools/clang/test/CodeGenSPIRV/vk.buffer-pointer.rvalue.hlsl

@@ -0,0 +1,35 @@
+// RUN: %dxc -spirv -HV 202x -Od -T cs_6_9 %s | FileCheck %s
+
+// Issue #7302: implicit object argument of Get() evaluates to rvalue
+
+template<class T, class U>
+[[vk::ext_instruction(/*spv::OpBitcast*/124)]]
+T bitcast(U);
+
+struct Content
+{
+  int a;
+};
+
+// CHECK: [[INT:%[_0-9A-Za-z]*]] = OpTypeInt 32 1
+// CHECK-DAG: [[I1:%[_0-9A-Za-z]*]] = OpConstant [[INT]] 1
+// CHECK-DAG: [[IO:%[_0-9A-Za-z]*]] = OpConstant [[INT]] 0
+// CHECK: [[UINT:%[_0-9A-Za-z]*]] = OpTypeInt 32 0
+// CHECK-DAG: [[UDEADBEEF:%[_0-9A-Za-z]*]] = OpConstant [[UINT]] 3735928559
+// CHECK-DAG: [[U0:%[_0-9A-Za-z]*]] = OpConstant [[UINT]] 0
+// CHECK: [[V2UINT:%[_0-9A-Za-z]*]] = OpTypeVector [[UINT]] 2
+// CHECK: [[VECTOR:%[_0-9A-Za-z]*]] = OpConstantComposite [[V2UINT]] [[UDEADBEEF]] [[U0]]
+// CHECK: [[CONTENT:%[_0-9A-Za-z]*]] = OpTypeStruct [[INT]]
+// CHECK: [[PPCONTENT:%[_0-9A-Za-z]*]] = OpTypePointer PhysicalStorageBuffer [[CONTENT]]
+// CHECK: [[PPINT:%[_0-9A-Za-z]*]] = OpTypePointer PhysicalStorageBuffer [[INT]]
+
+[numthreads(1, 1, 1)]
+void main()
+{
+  bitcast<vk::BufferPointer<Content> >(uint32_t2(0xdeadbeefu,0x0u)).Get().a = 1;
+}
+
+// CHECK: [[BITCAST:%[0-9]*]] = OpBitcast [[PPCONTENT]] [[VECTOR]]
+// CHECK: [[PTR:%[0-9]*]] = OpAccessChain [[PPINT]] [[BITCAST]] [[IO]]
+// CHECK: OpStore [[PTR]] [[I1]] Aligned 4
+