GCC Code Coverage Report

Line	Branch	Exec	Source
1			//======================================================================================================================
2			/*
3			POLYFLOAT - Extended precision floating points
4			Copyright : POLYFLOAT Contributors & Maintainers
5			SPDX-License-Identifier: BSL-1.0
6			*/
7			//======================================================================================================================
8			#pragma once
9
10			#include <polyfloat/details/callable.hpp>
11			#include <polyfloat/types/concepts.hpp>
12			#include <polyfloat/types/traits.hpp>
13			#include <type_traits>
14			#include <polyfloat/module/core/ldexp.hpp>
15			#include <polyfloat/module/core/frexp.hpp>
16			#include <polyfloat/module/core/mul.hpp>
17			#include <polyfloat/module/core/sqr.hpp>
18			#include <polyfloat/module/core/dec.hpp>
19			#include <polyfloat/module/core/if_else.hpp>
20			#include <polyfloat/module/core/mantissa.hpp>
21
22			namespace plf
23			{
24
25			template<typename Options> struct rsqrt_t : plf::callable<rsqrt_t, eve::rsqrt_t, Options, raw_option, pedantic_option>
26			{
27		82740	template<concepts::polyfloat_like Z> POLYFLOAT_ABI constexpr Z operator()(Z z) const noexcept
28			{
29		82740	return POLYFLOAT_CALL(z);
30			}
31
32		82728	POLYFLOAT_CALLABLE_OBJECT(rsqrt_t, rsqrt_);
33			};
34			//======================================================================================================================
35			//! @addtogroup core
36			//! @{
37			//! @var rsqrt
38			//! @brief return the inverse square root value.
39			//!
40			//! @groupheader{Header file}
41			//!
42			//! @code
43			//! #include <polyfloat/core.hpp>
44			//! @endcode
45			//!
46			//! @groupheader{Callable Signatures}
47			//!
48			//! @code
49			//! namespace polyfloat
50			//! {
51			//! template<polyfloat::concepts::polyfloat_like T> constexpr auto rsqrt(T z) noexcept;
52			//! template<polyfloat::concepts::polyfloat_like T> constexpr auto rsqrt[raw](T z) noexcept;
53			//! }
54			//! @endcode
55			//!
56			//! **Parameters**
57			//!
58			//! * `z`: Value to process.
59			//!
60			//! **Return value**
61			//!
62			//! Returns the inverse square root of z. With raw option the computation can overflow.
63			//!
64			//! @groupheader{Example}
65			//!
66			//! @godbolt{doc/core/rsqrt.cpp}
67			//======================================================================================================================
68
69			inline constexpr auto rsqrt = eve::functor<rsqrt_t>;
70			//======================================================================================================================
71			//! @}
72			//======================================================================================================================
73			}
74
75			namespace plf::_
76			{
77
78		82728	template<typename Z, eve::callable_options O> constexpr auto rsqrt_(POLYFLOAT_DELAY(), O const&, Z const& z) noexcept
79			{
80		59642	auto div2 = [](auto x) { return x * Z(0.5); };
81			if constexpr (!O::contains(eve::raw)) //avoid overflow;
82			{
83		82576	auto [zz, n] = frexp[pedantic](z);
84		41364	auto oddn = eve::is_odd(n);
85		41364	zz = plf::if_else(oddn, 2 * zz, zz);
86		41364	n = plf::dec[oddn](n);
87		41364	return ldexp(rsqrt[eve::raw](zz), -n / 2);
88			}
89			else if constexpr (dimension_v<Z> == 2)
90			{
91		4808	auto [a0, b0] = z;
92		4808	auto x0 = eve::rsqrt(a0);
93		4808	Z x1 = x0 + div2(x0 * (Z(1) - z * eve::sqr(x0)));
94		4808	Z x2 = x1 + div2(x1 * (Z(1) - z * plf::sqr(x1)));
95		4808	return x2;
96			}
97			else if constexpr (dimension_v<Z> == 3)
98			{
99		36556	auto [a0, b0, c0] = z;
100		36556	auto x0 = eve::rsqrt(a0);
101		36556	auto x1 = x0 + div2(x0 * (Z(1) - z * eve::sqr(x0)));
102		36556	auto x2 = x1 + div2(x1 * (Z(1) - z * plf::sqr(x1)));
103		36556	auto x3 = x2 + div2(x2 * (Z(1) - z * plf::sqr(x2)));
104		36556	return x3;
105			}
106			}
107			}
108