Implement the ObjectToWorld3x4 HLSL Function

[farzonl]

• Implement ObjectToWorld3x4 clang builtin,
• Link ObjectToWorld3x4 clang builtin with hlsl_intrinsics.h
• Add sema checks for ObjectToWorld3x4 to CheckHLSLBuiltinFunctionCall in SemaChecking.cpp
• Add codegen for ObjectToWorld3x4 to EmitHLSLBuiltinExpr in CGBuiltin.cpp
• Add codegen tests to clang/test/CodeGenHLSL/builtins/ObjectToWorld3x4.hlsl
• Add sema tests to clang/test/SemaHLSL/BuiltIns/ObjectToWorld3x4-errors.hlsl
• Create the int_dx_ObjectToWorld3x4 intrinsic in IntrinsicsDirectX.td
• Create the DXILOpMapping of int_dx_ObjectToWorld3x4 to 151 in DXIL.td
• Create the ObjectToWorld3x4.ll and ObjectToWorld3x4_errors.ll tests in llvm/test/CodeGen/DirectX/
• Create the int_spv_ObjectToWorld3x4 intrinsic in IntrinsicsSPIRV.td
• In SPIRVInstructionSelector.cpp create the ObjectToWorld3x4 lowering and map it to int_spv_ObjectToWorld3x4 in SPIRVInstructionSelector::selectIntrinsic.
• Create SPIR-V backend test case in llvm/test/CodeGen/SPIRV/hlsl-intrinsics/ObjectToWorld3x4.ll

DirectX

DXIL Opcode	DXIL OpName	Shader Model	Shader Stages
151	ObjectToWorld	6.3	('library', 'intersection', 'anyhit', 'closesthit')

SPIR-V

ObjectToWorldKHR

Short Description

ObjectToWorldKHR - Transformation matrix from object to world space

Description

ObjectToWorldKHR
A variable decorated with the ObjectToWorldKHR decoration will
contain the current object-to-world transformation matrix, which is
determined by the instance of the current intersection.

Valid Usage

• 
  VUID-ObjectToWorldKHR-ObjectToWorldKHR-04305
  
  The ObjectToWorldKHR decoration must be used only within the
  IntersectionKHR , AnyHitKHR , or ClosestHitKHR
Execution Model

• 
  VUID-ObjectToWorldKHR-ObjectToWorldKHR-04306
  
  The variable decorated with ObjectToWorldKHR must be declared
  using the Input Storage Class

• 
  VUID-ObjectToWorldKHR-ObjectToWorldKHR-04307
  
  The variable decorated with ObjectToWorldKHR must be declared
  as a matrix with four columns of three-component vectors of 32-bit
  floating-point values

Test Case(s)

Example 1

//dxc ObjectToWorld3x4_test.hlsl -T lib_6_8 -enable-16bit-types -O0

export float3x4 fn() {
    return ObjectToWorld3x4();
}

SPIRV Example(s):

Example 2

//dxc ObjectToWorld3x4_spirv_test.hlsl -T lib_6_8 -E fn -enable-16bit-types -spirv -fspv-target-env=universal1.5 -fcgl -O0

[shader("intersection")]
void fn() {
float3x4 	ret = ObjectToWorld3x4();
}

HLSL:

A matrix for transforming from object-space to world-space. Object-space refers to the space of the current bottom-level acceleration structure.

Syntax

float3x4 ObjectToWorld3x4();

Remarks

The matrix is a transposition of ObjectToWorld4x3 matrix.

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