Implement the ReportHit HLSL Function

[farzonl]

• Implement ReportHit clang builtin,
• Link ReportHit clang builtin with hlsl_intrinsics.h
• Add sema checks for ReportHit to CheckHLSLBuiltinFunctionCall in SemaChecking.cpp
• Add codegen for ReportHit to EmitHLSLBuiltinExpr in CGBuiltin.cpp
• Add codegen tests to clang/test/CodeGenHLSL/builtins/ReportHit.hlsl
• Add sema tests to clang/test/SemaHLSL/BuiltIns/ReportHit-errors.hlsl
• Create the int_dx_ReportHit intrinsic in IntrinsicsDirectX.td
• Create the DXILOpMapping of int_dx_ReportHit to 158 in DXIL.td
• Create the ReportHit.ll and ReportHit_errors.ll tests in llvm/test/CodeGen/DirectX/
• Create the int_spv_ReportHit intrinsic in IntrinsicsSPIRV.td
• In SPIRVInstructionSelector.cpp create the ReportHit lowering and map it to int_spv_ReportHit in SPIRVInstructionSelector::selectIntrinsic.
• Create SPIR-V backend test case in llvm/test/CodeGen/SPIRV/hlsl-intrinsics/ReportHit.ll

DirectX

DXIL Opcode	DXIL OpName	Shader Model	Shader Stages
158	ReportHit	6.3	('library', 'intersection')

SPIR-V

OpReportIntersectionKHR:

Description:

(OpReportIntersectionNV)**

Reserved.

Capability:
RayTracingNV, RayTracingKHR

Reserved.

Word Count	Opcode	Results	Operands
5	5334	<id> Result Type	Result <id>	<id> Hit	<id> HitKind

Test Case(s)

Example 1

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

struct RayPayload
{
	float4 color;
	float distance;
};
export bool fn(float p1, uint p2, RayPayload p3) {
    return ReportHit(p1, p2, p3);
}

HLSL:

Called by an intersection shader to report a ray intersection.

Syntax

This intrinsic function definition is equivalent to the following function template:

template<attr_t>
bool ReportHit(float THit, uint HitKind, attr_t Attributes);

Parameters

THit

A float value specifying the parametric distance of the intersection..

HitKind

An unsigned integer that identifies the type of hit that occurred. This is a user-specified value in the range of 0-127. The value can be read by any hit or closest hit shaders with the HitKind intrinsic.

Attributes

The user-defined Intersection Attribute Structure structure specifying the intersection attributes.

Return Value

bool True if the hit was accepted. A hit is rejected if THit is outside the current ray interval, or the any hit shader calls IgnoreHit. The current ray interval is defined by RayTMin and RayTCurrent.

Remarks

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

• Intersection Shader

See also

Direct3D 12 Raytracing HLSL Reference