Implement the WaveActiveAllEqual HLSL Function

[farzonl]

• Implement WaveActiveAllEqual clang builtin,
• Link WaveActiveAllEqual clang builtin with hlsl_intrinsics.h
• Add sema checks for WaveActiveAllEqual to CheckHLSLBuiltinFunctionCall in SemaChecking.cpp
• Add codegen for WaveActiveAllEqual to EmitHLSLBuiltinExpr in CGBuiltin.cpp
• Add codegen tests to clang/test/CodeGenHLSL/builtins/WaveActiveAllEqual.hlsl
• Add sema tests to clang/test/SemaHLSL/BuiltIns/WaveActiveAllEqual-errors.hlsl
• Create the int_dx_WaveActiveAllEqual intrinsic in IntrinsicsDirectX.td
• Create the DXILOpMapping of int_dx_WaveActiveAllEqual to 115 in DXIL.td
• Create the WaveActiveAllEqual.ll and WaveActiveAllEqual_errors.ll tests in llvm/test/CodeGen/DirectX/
• Create the int_spv_WaveActiveAllEqual intrinsic in IntrinsicsSPIRV.td
• In SPIRVInstructionSelector.cpp create the WaveActiveAllEqual lowering and map it to int_spv_WaveActiveAllEqual in SPIRVInstructionSelector::selectIntrinsic.
• Create SPIR-V backend test case in llvm/test/CodeGen/SPIRV/hlsl-intrinsics/WaveActiveAllEqual.ll

DirectX

DXIL Opcode	DXIL OpName	Shader Model	Shader Stages
115	WaveActiveAllEqual	6.0	('library', 'compute', 'amplification', 'mesh', 'pixel', 'vertex', 'hull', 'domain', 'geometry', 'raygeneration', 'intersection', 'anyhit', 'closesthit', 'miss', 'callable', 'node')

SPIR-V

OpGroupNonUniformAllEqual:

Description:

Evaluates a value for all active invocations in the group. The
result is true if Value is equal for all active invocations in the
group. Otherwise, the result is false.

Result Type must be a Boolean type.

Execution is a Scope that identifies the group of
invocations affected by this command. It must be Subgroup.

Value must be a scalar or vector of floating-point
type, integer type, or Boolean
type. The compare operation is based on this type, and if it
is a floating-point type, an ordered-and-equal compare is used.

Capability:
GroupNonUniformVote

Missing before version 1.3.

Word Count	Opcode	Results	Operands
5	336	<id> Result Type	Result <id>	Scope <id> Execution	<id> Value

Test Case(s)

Example 1

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

export bool4 fn(float4 p1) {
    return WaveActiveAllEqual(p1);
}

HLSL:

Returns true if the expression is the same for every active lane in the current wave (and thus uniform across it).

Syntax

<bool-type> WaveActiveAllEqual(
   <type> expr
);

Parameters

expr

The expression to evaluate.
<type> can be a basic scalar, vector, or matrix type.

Return value

Returns true for each component of expr that is the same for every active lane in the current wave.

<bool-type> will be a scalar, vector, or matrix of bool, matching the dimensionality of the input <type>.
For instance, an input <type> of matrix<float, 4, 3> will result in a return <bool-type> of matrix<bool, 4, 3>.

Remarks

This function is supported from shader model 6.0 in all shader stages.

 

See also

Overview of Shader Model 6

Shader Model 6