Implement the ObjectRayOrigin HLSL Function

[farzonl]

• Implement ObjectRayOrigin clang builtin,
• Link ObjectRayOrigin clang builtin with hlsl_intrinsics.h
• Add sema checks for ObjectRayOrigin to CheckHLSLBuiltinFunctionCall in SemaChecking.cpp
• Add codegen for ObjectRayOrigin to EmitHLSLBuiltinExpr in CGBuiltin.cpp
• Add codegen tests to clang/test/CodeGenHLSL/builtins/ObjectRayOrigin.hlsl
• Add sema tests to clang/test/SemaHLSL/BuiltIns/ObjectRayOrigin-errors.hlsl
• Create the int_dx_ObjectRayOrigin intrinsic in IntrinsicsDirectX.td
• Create the DXILOpMapping of int_dx_ObjectRayOrigin to 149 in DXIL.td
• Create the ObjectRayOrigin.ll and ObjectRayOrigin_errors.ll tests in llvm/test/CodeGen/DirectX/
• Create the int_spv_ObjectRayOrigin intrinsic in IntrinsicsSPIRV.td
• In SPIRVInstructionSelector.cpp create the ObjectRayOrigin lowering and map it to int_spv_ObjectRayOrigin in SPIRVInstructionSelector::selectIntrinsic.
• Create SPIR-V backend test case in llvm/test/CodeGen/SPIRV/hlsl-intrinsics/ObjectRayOrigin.ll

DirectX

DXIL Opcode	DXIL OpName	Shader Model	Shader Stages
149	ObjectRayOrigin	6.3	('library', 'intersection', 'anyhit', 'closesthit')

SPIR-V

ObjectRayOriginKHR

Short Description

ObjectRayOriginKHR - Ray origin in object space

Description

ObjectRayOriginKHR
A variable decorated with the ObjectRayOriginKHR decoration will
specify the origin of the ray being processed, in object space.

Valid Usage

• 
  VUID-ObjectRayOriginKHR-ObjectRayOriginKHR-04302
  
  The ObjectRayOriginKHR decoration must be used only within the
  IntersectionKHR , AnyHitKHR , or ClosestHitKHR
Execution Model

• 
  VUID-ObjectRayOriginKHR-ObjectRayOriginKHR-04303
  
  The variable decorated with ObjectRayOriginKHR must be
  declared using the Input Storage Class

• 
  VUID-ObjectRayOriginKHR-ObjectRayOriginKHR-04304
  
  The variable decorated with ObjectRayOriginKHR must be
  declared as a three-component vector of 32-bit floating-point values

Test Case(s)

Example 1

//dxc ObjectRayOrigin_test.hlsl -T lib_6_8 -enable-16bit-types -O0

export float3 fn() {
    return ObjectRayOrigin();
}

SPIRV Example(s):

Example 2

//dxc ObjectRayOrigin_spirv_test.hlsl -T lib_6_8 -E fn -enable-16bit-types -spirv -fspv-target-env=universal1.5 -fcgl -O0

[shader("intersection")]
void fn() {
float3 	ret = ObjectRayOrigin();
}

HLSL:

The object-space origin for the current ray. Object-space refers to the space of the current bottom-level acceleration structure.

Syntax

float3 ObjectRayOrigin();

Remarks

This function can be called from the following raytracing shader types:

• Any Hit Shader
• Closest Hit Shader
• Intersection Shader

See also

Direct3D 12 Raytracing HLSL Reference