MathFunctionImpl< VectorWidth, MathOp::Acos > Struct Template Reference

#include <llvmexpr/codegen/llvm/Math.hpp>

Static Public Member Functions
static llvm::Function *	generate (MathFunctionGenerator< VectorWidth > *gen)

Detailed Description

template<int VectorWidth>
struct MathFunctionImpl< VectorWidth, MathOp::Acos >

Definition at line 683 of file Math.hpp.

Member Function Documentation

generate()

template<int VectorWidth>

llvm::Function * MathFunctionImpl< VectorWidth, MathOp::Acos >::generate ( MathFunctionGenerator< VectorWidth > * gen )

inlinestatic

Definition at line 684 of file Math.hpp.

                                                                           {
        constexpr auto OP_INFO = get_math_op_info(MathOp::Acos);
        // https://forwardscattering.org/post/66
        // TODO: Switch to another implementation that doesn't has licensing issues.
        return gen->createFunction(
            OP_INFO.name, OP_INFO.arity,
            [gen](llvm::ArrayRef<llvm::Value*> args) -> llvm::Value* {
                auto* x = args[0];
                auto* pi = gen->getConstant(std::numbers::pi_v<float>);
                auto* ax = gen->createIntrinsicCall(llvm::Intrinsic::fabs, {x});
                // NOLINTBEGIN(cppcoreguidelines-avoid-magic-numbers)
                auto* term1_mul = gen->getConstant(-0.124605335F);
                auto* term1_add = gen->getConstant(0.1570634F);
                auto* term1 = gen->createIntrinsicCall(
                    llvm::Intrinsic::fma, {ax, term1_mul, term1_add});
 
                auto* term2_sub = gen->getConstant(0.99418175F);
                auto* term2 = gen->builder.CreateFSub(term2_sub, ax);
 
                auto* poly_part = gen->builder.CreateFMul(term1, term2);
 
                auto* two = gen->getConstant(2.0F);
                auto* neg_two = gen->getConstant(-2.0F);
                // NOLINTEND(cppcoreguidelines-avoid-magic-numbers)
                auto* sqrt_arg = gen->createIntrinsicCall(llvm::Intrinsic::fma,
                                                          {ax, neg_two, two});
                auto* sqrt_part =
                    gen->createIntrinsicCall(llvm::Intrinsic::sqrt, {sqrt_arg});
 
                auto* res_pos = gen->builder.CreateFAdd(poly_part, sqrt_part);
 
                auto* zero = gen->getConstant(0.0F);
                auto* is_neg = gen->builder.CreateFCmpOLT(x, zero);
 
                auto* res_neg = gen->builder.CreateFSub(pi, res_pos);
 
                return gen->builder.CreateSelect(is_neg, res_neg, res_pos);
            });
    }

References Acos, and get_math_op_info().

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The documentation for this struct was generated from the following file:

• llvmexpr/codegen/llvm/Math.hpp