Implement the WorldToObject3x4 HLSL Function

[farzonl]

• Implement WorldToObject3x4 clang builtin,
• Link WorldToObject3x4 clang builtin with hlsl_intrinsics.h
• Add sema checks for WorldToObject3x4 to CheckHLSLBuiltinFunctionCall in SemaChecking.cpp
• Add codegen for WorldToObject3x4 to EmitHLSLBuiltinExpr in CGBuiltin.cpp
• Add codegen tests to clang/test/CodeGenHLSL/builtins/WorldToObject3x4.hlsl
• Add sema tests to clang/test/SemaHLSL/BuiltIns/WorldToObject3x4-errors.hlsl
• Create the int_dx_WorldToObject3x4 intrinsic in IntrinsicsDirectX.td
• Create the DXILOpMapping of int_dx_WorldToObject3x4 to 152 in DXIL.td
• Create the WorldToObject3x4.ll and WorldToObject3x4_errors.ll tests in llvm/test/CodeGen/DirectX/
• Create the int_spv_WorldToObject3x4 intrinsic in IntrinsicsSPIRV.td
• In SPIRVInstructionSelector.cpp create the WorldToObject3x4 lowering and map it to int_spv_WorldToObject3x4 in SPIRVInstructionSelector::selectIntrinsic.
• Create SPIR-V backend test case in llvm/test/CodeGen/SPIRV/hlsl-intrinsics/WorldToObject3x4.ll

DirectX

DXIL Opcode	DXIL OpName	Shader Model	Shader Stages
152	WorldToObject	6.3	('library', 'intersection', 'anyhit', 'closesthit')

SPIR-V

WorldToObjectKHR

Short Description

WorldToObjectKHR - Transformation matrix from world to object space

Description

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

Valid Usage

• 
  VUID-WorldToObjectKHR-WorldToObjectKHR-04434
  
  The WorldToObjectKHR decoration must be used only within the
  IntersectionKHR , AnyHitKHR , or ClosestHitKHR
Execution Model

• 
  VUID-WorldToObjectKHR-WorldToObjectKHR-04435
  
  The variable decorated with WorldToObjectKHR must be declared
  using the Input Storage Class

• 
  VUID-WorldToObjectKHR-WorldToObjectKHR-04436
  
  The variable decorated with WorldToObjectKHR 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 WorldToObject3x4_test.hlsl -T lib_6_8 -enable-16bit-types -O0

export float3x4 fn() {
    return WorldToObject3x4();
}

SPIRV Example(s):

Example 2

//dxc WorldToObject3x4_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 = WorldToObject3x4();
}

HLSL:

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

Syntax

float3x4 WorldToObject3x4();

Remarks

The matrix is a transposition of WorldToObject4x3 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