[ ] Implement ldexp clang builtin,
[ ] Link ldexp clang builtin with hlsl_intrinsics.h
[ ] Add sema checks for ldexp to CheckHLSLBuiltinFunctionCall in SemaChecking.cpp
[ ] Add codegen for ldexp to EmitHLSLBuiltinExpr in CGBuiltin.cpp
[ ] Add codegen tests to clang/test/CodeGenHLSL/builtins/ldexp.hlsl
[ ] Add sema tests to clang/test/SemaHLSL/BuiltIns/ldexp-errors.hlsl
[ ] Create the int_dx_ldexp intrinsic in IntrinsicsDirectX.td
[ ] Create the DXILOpMapping of int_dx_ldexp to 21 in DXIL.td
[ ] Create the ldexp.ll and ldexp_errors.ll tests in llvm/test/CodeGen/DirectX/
[ ] Create the int_spv_ldexp intrinsic in IntrinsicsSPIRV.td
[ ] In SPIRVInstructionSelector.cpp create the ldexp lowering and map it to int_spv_ldexp in SPIRVInstructionSelector::selectIntrinsic.
[ ] Create SPIR-V backend test case in llvm/test/CodeGen/SPIRV/hlsl-intrinsics/ldexp.ll

DirectX

DXIL Opcode	DXIL OpName	Shader Model	Shader Stages
21	Exp	6.0	()

SPIR-V

Exp2

Result is 2 raised to the x power; 2^x.

The operand x must be a scalar or vector whose component type is 16-bit or 32-bit floating-point.

Result Type and the type of x must be the same type. Results are computed per component.

Number	Operand 1	Operand 2	Operand 3	Operand 4
29	<id> x

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

export float4 fn(float4 p1, float4 p2) {
    return ldexp(p1, p2);
}

Returns the result of multiplying the specified value by two, raised to the power of the specified exponent.

ret ldexp(x, exp)

This function uses the following formula: x * 2^exp

Item	Description
x	[in] The specified value.
exp	[in] The specified exponent.

The result of multiplying the x parameter by two, raised to the power of the exp parameter.

Name	Template Type	Component Type	Size
x	scalar, vector, or matrix	float	any
exp	same as input x	float	same dimension(s) as input x
ret	same as input x	float	same dimension(s) as input x

This function is supported in the following shader models.

Shader Model	Supported
Shader Model 2 (DirectX HLSL) and higher shader models	yes
Shader Model 1 (DirectX HLSL)	yes (vs_1_1 only)

Requirement	Value
Header	Corecrt_math.h