/*
* Brickworks
*
* Copyright (C) 2021-2024 Orastron Srl unipersonale
*
* Brickworks is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License.
*
* Brickworks is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Brickworks. If not, see .
*
* File author: Stefano D'Angelo
*/
/*!
* module_type {{{ utility }}}
* version {{{ 1.0.1 }}}
* requires {{{ bw_common }}}
* description {{{
* A collection of mathematical routines that strive to be better suited to
* DSP than, e.g., those supplied by your C standard library.
*
* Such a goal is hopefully accomplished by:
*
* * being as branchless as reasonable/convenient;
* * not handling uninteresting corner cases, such as out-of-range,
* NaN, and sometimes infinity input values (out-of-range and NaN inputs
* are always considered invalid and lead to undefined behavior);
* * returning approximated results (indicated in this documentation);
* * making no distinction between `0.f` and `-0.f`.
*
* In practice they should guarantee fast and consistent performance, but
* always do your own benchmarking.
*
* All functions in this module are [reentrant](api#reentrant-function),
* [RT-safe](api#rt-safe-function), [thread-safe](api#thread-safe-function),
* and have [no side effects](api#no-side-effects).
* }}}
* changelog {{{
*
* - Version 1.0.1:
*
* - Now using
BW_NULL.
* - Fixed sign-related warnings in
bw_truncf(),
* bw_roundf(), and bw_sqrtf().
*
*
* - Version 1.0.0:
*
* - Renamed
bw_min0xf() as bw_min0f() and
* bw_max0xf() as bw_max0f().
* - Removed precision suffixes from function names.
* - New implementations for
bw_min0f(),
* bw_max0f(), bw_minf(),
* bw_maxf(), and bw_clipf().
* - Fixed rounding bug in
bw_roundf() when absolute
* value of input was in [0.5f,
* 1.f].
* - Fixed
bw_ceilf() for negative input values.
* - Fixed
bw_sqrtf() for very large input values and
* improved implementation.
* - Fixed input validity ranges in
bw_asinhf() and
* bw_acoshf().
* - Added
BW_RESTRICT specifiers to input
* arguments of bw_intfracf().
* - Removed usage of reserved identifiers and designated
* initializers.
* - Added
extern "C" to functions.
* - Added more debugging checks in
bw_intfracf().
* - Improved documentation w.r.t. validity of input values and
* approximation errors.
*
*
* - Version 0.6.0:
*
* - Added debugging code.
* - Removed dependency on bw_config.
* - Removed
bw_omega_3log() and
* bw_omega_3lognr().
* - Fixed
bw_pow10f_3() and
* bw_acoshf_3().
*
*
* - Version 0.4.0:
*
* - Added
bw_ceilf(), bw_intfracf(),
* bw_sinhf_3(), bw_coshf_3(),
* bw_asinhf_3(), and bw_acoshf_3().
*
*
* - Version 0.3.0:
*
* - Added
bw_log10f_3(), bw_pow10f_3(),
* bw_dB2linf_3(), and
* bw_lin2dBf_3().
* - Fixed computation bug in
bw_sqrtf_2().
*
*
* - Version 0.2.0:
*
* - Added
bw_sin2pif_3(), bw_cos2pif_3(),
* bw_tan2pif_3(), bw_omega_3lognr(), and
* bw_tanhf_3().
*
*
* - Version 0.1.0:
*
*
*
* }}}
*/
#ifndef BW_MATH_H
#define BW_MATH_H
#include
#ifdef __cplusplus
extern "C" {
#endif
/*** Public API ***/
/*! api {{{
* #### bw_signfilli32()
* ```>>> */
static inline int32_t bw_signfilli32(
int32_t x);
/*! <<<```
* Returns `~0` if `x` is negative, `0` otherwise.
*
* #### bw_mini32()
* ```>>> */
static inline int32_t bw_mini32(
int32_t a,
int32_t b);
/*! <<<```
* Returns the minimum of `a` and `b`.
*
* #### bw_maxi32()
* ```>>> */
static inline int32_t bw_maxi32(
int32_t a,
int32_t b);
/*! <<<```
* Returns the maximum of `a` and `b`.
*
* #### bw_clipi32()
* ```>>> */
static inline int32_t bw_clipi32(
int32_t x,
int32_t m,
int32_t M);
/*! <<<```
* Returns `x` unless it is smaller than `m`, in which case it returns `m`,
* or bigger than `M`, in which case it returns `M`.
*
* #### bw_minu32()
* ```>>> */
static inline uint32_t bw_minu32(
uint32_t a,
uint32_t b);
/*! <<<```
* Returns the minimum of `a` and `b`.
*
* #### bw_maxu32()
* ```>>> */
static inline uint32_t bw_maxu32(
uint32_t a,
uint32_t b);
/*! <<<```
* Returns the maximum of `a` and `b`.
*
* #### bw_clipu32()
* ```>>> */
static inline uint32_t bw_clipu32(
uint32_t x,
uint32_t m,
uint32_t M);
/*! <<<```
* Returns `x` unless it is smaller than `m`, in which case it returns `m`,
* or bigger than `M`, in which case it returns `M`.
*
* #### bw_copysignf()
* ```>>> */
static inline float bw_copysignf(
float x,
float y);
/*! <<<```
* Returns a value that has the absolute value of `x` and the sign of `y`.
*
* #### bw_signf()
* ```>>> */
static inline float bw_signf(
float x);
/*! <<<```
* Returns `1.f` if `x > 0.f`, `-1.f` if `x < 0.f` and `0.f` if `x == 0.f`.
*
* #### bw_absf()
* ```>>> */
static inline float bw_absf(
float x);
/*! <<<```
* Returns the absolute value of `x`.
*
* #### bw_min0f()
* ```>>> */
static inline float bw_min0f(
float x);
/*! <<<```
* Returns the minimum of `0.f` and `x`.
*
* #### bw_max0f()
* ```>>> */
static inline float bw_max0f(
float x);
/*! <<<```
* Returns the maximum of `0.f` and `x`.
*
* #### bw_minf()
* ```>>> */
static inline float bw_minf(
float a,
float b);
/*! <<<```
* Returns the minimum of `a` and `b`.
*
* #### bw_maxf()
* ```>>> */
static inline float bw_maxf(
float a,
float b);
/*! <<<```
* Returns the maximum of `a` and `b`.
*
* #### bw_clipf()
* ```>>> */
static inline float bw_clipf(
float x,
float m,
float M);
/*! <<<```
* Returns `x` unless it is smaller than `m`, in which case it returns `m`,
* or bigger than `M`, in which case it returns `M`.
*
* `M` must be greater than or equal to `m`.
*
* #### bw_truncf()
* ```>>> */
static inline float bw_truncf(
float x);
/*! <<<```
* Returns `x` with its fractional part set to zero (i.e., rounded towards
* zero).
*
* `x` must be finite.
*
* #### bw_roundf()
* ```>>> */
static inline float bw_roundf(
float x);
/*! <<<```
* Returns `x` rounded to the nearest integer.
*
* Halfway cases are rounded away from zero. E.g., `bw_roundf(0.5f)` gives
* `1.f` and `bw_roundf(-0.5f)` gives `-1.f`.
*
* `x` must be finite.
*
* #### bw_floorf()
* ```>>> */
static inline float bw_floorf(
float x);
/*! <<<```
* Returns the biggest integer less or equal than `x` (i.e., `x` is rounded
* down).
*
* `x` must be finite.
*
* #### bw_ceilf()
* ```>>> */
static inline float bw_ceilf(
float x);
/*! <<<```
* Returns the smallest integer greater or equal than `x` (i.e., `x` is
* rounded up).
*
* `x` must be finite.
*
* #### bw_intfracf()
* ```>>> */
static inline void bw_intfracf(
float x,
float * BW_RESTRICT i,
float * BW_RESTRICT f);
/*! <<<```
* Puts the integer part (floor) of `x` in `i` and the fractional part in
* `f`.
*
* `x` must be finite.
*
* #### bw_rcpf()
* ```>>> */
static inline float bw_rcpf(
float x);
/*! <<<```
* Returns the reciprocal of `x` (i.e., `1.f / x`).
*
* |`x`| must be in [`8.077935669463161e-28f`, `1.237940039285380e+27`].
*
* Relative error < 0.0013%.
*
* #### bw_sin2pif()
* ```>>> */
static inline float bw_sin2pif(
float x);
/*! <<<```
* Returns an approximation of the sine of 2 * pi * `x`, where `x` is given
* in radians.
*
* `x` must be finite.
*
* Absolute error < 0.011 or relative error < 1.7%, whatever is worse.
*
* #### bw_sinf()
* ```>>> */
static inline float bw_sinf(
float x);
/*! <<<```
* Returns an approximation of the sine of `x`, where `x` is given in
* radians.
*
* `x` must be finite.
*
* Absolute error < 0.011 or relative error < 1.7%, whatever is worse.
*
* #### bw_cos2pif()
* ```>>> */
static inline float bw_cos2pif(
float x);
/*! <<<```
* Returns an approximation of the cosine of 2 * pi * `x`, where `x` is given
* in radians.
*
* `x` must be finite.
*
* Absolute error < 0.011 or relative error < 1.7%, whatever is worse.
*
* #### bw_cosf()
* ```>>> */
static inline float bw_cosf(
float x);
/*! <<<```
* Returns an approximation of the cosine of `x`, where `x` is given in
* radians.
*
* `x` must be finite.
*
* Absolute error < 0.011 or relative error < 1.7%, whatever is worse.
*
* #### bw_tan2pif()
* ```>>> */
static inline float bw_tan2pif(
float x);
/*! <<<```
* Returns an approximation of the tangent of 2 * pi * `x`, where `x` is
* given in radians.
*
* `x` must be finite and in [-1/4 + 5e-4f / pi, 1/4 - 5e-4f / pi] + k / 2,
* where k is any integer number.
*
* Absolute error < 0.06 or relative error < 0.8%, whatever is worse.
*
* #### bw_tanf()
* ```>>> */
static inline float bw_tanf(
float x);
/*! <<<```
* Returns an approximation of the tangent of `x`, where `x` is given in
* radians.
*
* `x` must be finite and in [-pi/2 + 1e-3f, pi/2 - 1e-3f] + k * pi, where k
* is any integer number.
*
* Absolute error < 0.06 or relative error < 0.8%, whatever is worse.
*
* #### bw_log2f()
* ```>>> */
static inline float bw_log2f(
float x);
/*! <<<```
* Returns an approximation of the base-2 logarithm of `x`.
*
* `x` must be finite and greater than or equal to `1.175494350822287e-38f`.
*
* Absolute error < 0.0055 or relative error < 1.2%, whatever is worse.
*
* #### bw_logf()
* ```>>> */
static inline float bw_logf(
float x);
/*! <<<```
* Returns an approximation of the natural logarithm of `x`.
*
* `x` must be finite and greater than or equal to `1.175494350822287e-38f`.
*
* Absolute error < 0.0038 or relative error < 1.2%, whatever is worse.
*
* #### bw_log10f()
* ```>>> */
static inline float bw_log10f(
float x);
/*! <<<```
* Returns an approximation of the base-10 logarithm of `x`.
*
* `x` must be finite and greater than or equal to `1.175494350822287e-38f`.
*
* Absolute error < 0.0017 or relative error < 1.2%, whatever is worse.
*
* #### bw_pow2f()
* ```>>> */
static inline float bw_pow2f(
float x);
/*! <<<```
* Returns an approximation of 2 raised to the power of `x`. For `x < -126.f`
* it just returns `0.f`.
*
* `x` must be less than or equal to `127.999f`.
*
* Relative error < 0.062%.
*
* #### bw_expf()
* ```>>> */
static inline float bw_expf(
float x);
/*! <<<```
* Returns an approximation of e (Euler's number) raised to the power of `x`.
* For `x < -87.3365447505531f` it just returns `0`.
*
* `x` must be less than or equal to `88.722f`.
*
* Relative error < 0.062%.
*
* #### bw_pow10f()
* ```>>> */
static inline float bw_pow10f(
float x);
/*! <<<```
* Returns an approximation of 10 raised to the power of `x`. For
* `x < -37.92977945366162f` it just returns `0`.
*
* `x` must be less than or equal to `38.531f`.
*
* Relative error < 0.062%.
*
* #### bw_dB2linf()
* ```>>> */
static inline float bw_dB2linf(
float x);
/*! <<<```
* Returns an approximation of 10 raised to the power of `x` / 20 (dB to
* linear ratio conversion). For `x < -758.5955890732315f` it just returns
* `0.f`.
*
* `x` must be less than or equal to `770.630f`.
*
* Relative error < 0.062%.
*
* #### bw_lin2dBf()
* ```>>> */
static inline float bw_lin2dBf(
float x);
/*! <<<```
* Returns an approximation of 20 times the base-10 logarithm of `x` (linear
* ratio to dB conversion).
*
* `x` must be finite and greater than or equal to `1.175494350822287e-38f`.
*
* Absolute error < 0.032 or relative error < 1.2%, whatever is worse.
*
* #### bw_sqrtf()
* ```>>> */
static inline float bw_sqrtf(
float x);
/*! <<<```
* Returns an approximation of the square root of `x`.
*
* `x` must be finite and non-negative.
*
* Absolute error < 1.09e-19 or relative error < 0.0007%, whatever is worse.
*
* #### bw_tanhf()
* ```>>> */
static inline float bw_tanhf(
float x);
/*! <<<```
* Returns an approximation of the hyperbolic tangent of `x`.
*
* Absolute error < 0.035 or relative error < 6.5%, whatever is worse.
*
* #### bw_sinhf()
* ```>>> */
static inline float bw_sinhf(
float x);
/*! <<<```
* Returns an approximation of the hyperbolic sine of `x`.
*
* |`x`| must less than or equal to `88.722f`.
*
* Absolute error < 1e-7 or relative error < 0.07%, whatever is worse.
*
* #### bw_coshf()
* ```>>> */
static inline float bw_coshf(
float x);
/*! <<<```
* Returns an approximation of the hyperbolic cosine of `x`.
*
* |`x`| must less than or equal to `88.722f`.
*
* Relative error < 0.07%.
*
* #### bw_asinhf()
* ```>>> */
static inline float bw_asinhf(
float x);
/*! <<<```
* Returns an approximation of the hyperbolic arcsine of `x`.
*
* |`x`| must less than or equal to `8.507059173023462e+37f`.
*
* Absolute error < 0.004 or relative error < 1.2%, whatever is worse.
*
* #### bw_acoshf()
* ```>>> */
static inline float bw_acoshf(
float x);
/*! <<<```
* Returns an approximation of the hyperbolic arccosine of `x`.
*
* `x` must be in [1.f, 8.507059173023462e+37f].
*
* Absolute error < 0.004 or relative error < 0.8%, whatever is worse.
* }}} */
#ifdef __cplusplus
}
#endif
/*** Implementation ***/
/* WARNING: This part of the file is not part of the public API. Its content may
* change at any time in future versions. Please, do not use it directly. */
#ifdef __cplusplus
extern "C" {
#endif
// I hope the target architecture and compiler will use conditional ops here
static inline int32_t bw_signfilli32(
int32_t x) {
return x < 0 ? ~0 : 0;
}
static inline int32_t bw_mini32(
int32_t a,
int32_t b) {
return a < b ? a : b;
}
static inline int32_t bw_maxi32(
int32_t a,
int32_t b) {
return a > b ? a : b;
}
static inline int32_t bw_clipi32(
int32_t x,
int32_t m,
int32_t M) {
return x < m ? m : (x > M ? M : x);
}
static inline uint32_t bw_minu32(
uint32_t a,
uint32_t b) {
return a < b ? a : b;
}
static inline uint32_t bw_maxu32(
uint32_t a,
uint32_t b) {
return a > b ? a : b;
}
static inline uint32_t bw_clipu32(
uint32_t x,
uint32_t m,
uint32_t M) {
return x < m ? m : (x > M ? M : x);
}
// Here instead I don't trust C semantics to get close to conditional ops for
// floating point numbers
static inline float bw_copysignf(
float x,
float y) {
BW_ASSERT(!bw_is_nan(x));
BW_ASSERT(!bw_is_nan(y));
union { float f; uint32_t u; } v, s;
v.f = x;
s.f = y;
v.u = (v.u & 0x7fffffffu) | (s.u & 0x80000000u);
BW_ASSERT(!bw_is_nan(v.f));
return v.f;
}
static inline float bw_signf(
float x) {
BW_ASSERT(!bw_is_nan(x));
static const float y[4] = { 0.f, 1.f, 0.f, -1.f };
union { float f; uint32_t u; } v;
v.f = x;
const float r = y[bw_minu32(v.u & 0x7fffffffu, 1) | ((v.u >> 30) & 0x2)];
BW_ASSERT(!bw_is_nan(r));
return r;
}
static inline float bw_absf(
float x) {
BW_ASSERT(!bw_is_nan(x));
union { float f; uint32_t u; } v;
v.f = x;
v.u = v.u & 0x7fffffffu;
BW_ASSERT(!bw_is_nan(v.f));
return v.f;
}
static inline float bw_min0f(
float x) {
BW_ASSERT(!bw_is_nan(x));
union { float f; int32_t i; } v;
v.f = x;
v.i = bw_mini32(0, v.i);
BW_ASSERT(!bw_is_nan(v.f));
return v.f;
}
static inline float bw_max0f(
float x) {
BW_ASSERT(!bw_is_nan(x));
union { float f; int32_t i; } v;
v.f = x;
v.i = bw_maxi32(0, v.i);
BW_ASSERT(!bw_is_nan(v.f));
return v.f;
}
static inline float bw_minf(
float a,
float b) {
BW_ASSERT(!bw_is_nan(a));
BW_ASSERT(!bw_is_nan(b));
const float y = a < b ? a : b;
BW_ASSERT(!bw_is_nan(y));
return y;
}
static inline float bw_maxf(
float a,
float b) {
BW_ASSERT(!bw_is_nan(a));
BW_ASSERT(!bw_is_nan(b));
const float y = a > b ? a : b;
BW_ASSERT(!bw_is_nan(y));
return y;
}
static inline float bw_clipf(
float x,
float m,
float M) {
BW_ASSERT(!bw_is_nan(x));
BW_ASSERT(!bw_is_nan(m));
BW_ASSERT(!bw_is_nan(M));
BW_ASSERT(M >= m);
const float y = bw_minf(bw_maxf(x, m), M);
BW_ASSERT(!bw_is_nan(y));
return y;
}
static inline float bw_truncf(
float x) {
BW_ASSERT(bw_is_finite(x));
union { float f; uint32_t u; } v;
v.f = x;
const int32_t ex = (v.u & 0x7f800000u) >> 23;
uint32_t m = (~0u) << bw_clipi32(150 - ex, 0, 23);
m &= (uint32_t)bw_signfilli32(126 - ex) | 0x80000000;
v.u &= m;
BW_ASSERT(bw_is_finite(v.f));
return v.f;
}
static inline float bw_roundf(
float x) {
BW_ASSERT(bw_is_finite(x));
union { float f; uint32_t u; } v, s;
v.f = x;
const int32_t ex = (v.u & 0x7f800000u) >> 23;
const int32_t sh = bw_clipi32(150 - ex, 0, 24);
uint32_t mt = (~0u) << sh;
mt &= (uint32_t)bw_signfilli32(126 - ex) | 0x80000000;
uint32_t mr = (1u << sh) >> 1;
mr &= (uint32_t)bw_signfilli32(125 - ex);
s.f = bw_copysignf(1.f, x);
uint32_t ms = (uint32_t)bw_signfilli32((int32_t)(((v.u | 0x00800000u) & mr) << (32 - sh)));
v.u &= mt;
s.u &= ms;
const float y = v.f + s.f;
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_floorf(
float x) {
BW_ASSERT(bw_is_finite(x));
union { float f; int32_t i; } t, y, s;
t.f = bw_truncf(x); // first bit set when t < 0
y.f = x - t.f; // first bit set when t > x
s.f = 1.f;
s.i &= bw_signfilli32(t.i & y.i);
const float r = t.f - s.f;
BW_ASSERT(bw_is_finite(r));
return r;
}
static inline float bw_ceilf(
float x) {
BW_ASSERT(bw_is_finite(x));
union { float f; int32_t i; } t, y, s;
t.f = bw_truncf(x); // first bit set when t < 0
y.f = t.f - x; // first bit set when t < x
s.f = 1.f;
s.i &= bw_signfilli32(~t.i & y.i);
const float r = t.f + s.f;
BW_ASSERT(bw_is_finite(r));
return r;
}
static inline void bw_intfracf(
float x,
float * BW_RESTRICT i,
float * BW_RESTRICT f) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(i != BW_NULL);
BW_ASSERT(f != BW_NULL);
BW_ASSERT(i != f);
*i = bw_floorf(x);
*f = x - *i;
BW_ASSERT(bw_is_finite(*i));
BW_ASSERT(bw_is_finite(*f));
}
static inline float bw_rcpf(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT((x >= 8.077935669e-28f && x <= 1.237940039e27f) || (x <= -8.077935669e-28f && x >= -1.237940039e27f));
union { float f; int32_t i; } v;
v.f = x;
v.i = 0x7ef0e840 - v.i;
v.f = v.f + v.f - x * v.f * v.f;
v.f = v.f + v.f - x * v.f * v.f;
BW_ASSERT(bw_is_finite(v.f));
return v.f;
}
static inline float bw_sin2pif(
float x) {
BW_ASSERT(bw_is_finite(x));
x = x - bw_floorf(x);
float xp1 = x + x - 1.f;
float xp2 = bw_absf(xp1);
float xp = 1.570796326794897f - 1.570796326794897f * bw_absf(xp2 + xp2 - 1.f);
const float y = -bw_copysignf(1.f, xp1) * (xp + xp * xp * (-0.05738534102710938f - 0.1107398163618408f * xp));
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_sinf(
float x) {
BW_ASSERT(bw_is_finite(x));
const float y = bw_sin2pif(0.1591549430918953f * x);
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_cos2pif(
float x) {
BW_ASSERT(bw_is_finite(x));
const float y = bw_sin2pif(x + 0.25f);
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_cosf(
float x) {
BW_ASSERT(bw_is_finite(x));
const float y = bw_cos2pif(0.1591549430918953f * x);
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_tan2pif(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT((x - 0.5f * bw_floorf(x + x) <= 0.249840845056908f)
|| (x - 0.5f * bw_floorf(x + x) >= 0.250159154943092f));
const float y = bw_sin2pif(x) * bw_rcpf(bw_cos2pif(x));
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_tanf(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT((x - 3.141592653589793f * bw_floorf(0.318309886183791f * x) <= 1.569796326794897f)
|| (x - 3.141592653589793f * bw_floorf(0.318309886183791f * x) >= 1.571796326794896f));
x = 0.1591549430918953f * x;
const float y = bw_sin2pif(x) * bw_rcpf(bw_cos2pif(x));
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_log2f(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= 1.175494350822287e-38f);
union { float f; int32_t i; } v;
v.f = x;
int e = v.i >> 23;
v.i = (v.i & 0x007fffff) | 0x3f800000;
const float y = (float)e - 129.213475204444817f + v.f * (3.148297929334117f + v.f * (-1.098865286222744f + v.f * 0.1640425613334452f));
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_logf(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= 1.175494350822287e-38f);
const float y = 0.693147180559945f * bw_log2f(x);
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_log10f(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= 1.175494350822287e-38f);
const float y = 0.3010299956639811f * bw_log2f(x);
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_pow2f(
float x) {
BW_ASSERT(!bw_is_nan(x));
BW_ASSERT(x <= 127.999f);
if (x < -126.f)
return 0.f;
union { float f; int32_t i; } v;
v.f = x;
int xi = (int)x;
int l = xi - ((v.i >> 31) & 1);
float f = x - (float)l;
v.i = (l + 127) << 23;
const float y = v.f + v.f * f * (0.6931471805599453f + f * (0.2274112777602189f + f * 0.07944154167983575f));
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_expf(
float x) {
BW_ASSERT(!bw_is_nan(x));
BW_ASSERT(x <= 88.722f);
const float y = bw_pow2f(1.442695040888963f * x);
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_pow10f(
float x) {
BW_ASSERT(!bw_is_nan(x));
BW_ASSERT(x <= 38.531f);
const float y = bw_pow2f(3.321928094887363f * x);
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_dB2linf(
float x) {
BW_ASSERT(!bw_is_nan(x));
BW_ASSERT(x <= 770.630f);
const float y = bw_pow2f(0.1660964047443682f * x);
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_lin2dBf(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= 1.175494350822287e-38f);
const float y = 20.f * bw_log10f(x);
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_sqrtf(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= 0.f);
if (x < 1.1754943508222875e-38f)
return 0.f;
union { float f; int32_t i; } v;
v.f = x;
int i = (v.i >> 26) & 0x38;
v.i += (int32_t)((0x200000e0 << i) & (int32_t)0xff000000);
const float r = bw_rcpf(v.f);
v.i = (((v.i - 0x3f82a127) >> 1) + 0x3f7d8fc7) & 0x7fffffff;
v.f = v.f + v.f * (0.5f - 0.5f * r * v.f * v.f);
v.f = v.f + v.f * (0.5f - 0.5f * r * v.f * v.f);
v.i -= (int32_t)((0x100000f0 << i) & (int32_t)0xff000000);
BW_ASSERT(bw_is_finite(v.f));
return v.f;
}
static inline float bw_tanhf(
float x) {
BW_ASSERT(!bw_is_nan(x));
const float xm = bw_clipf(x, -2.115287308554551f, 2.115287308554551f);
const float axm = bw_absf(xm);
const float y = xm * axm * (0.01218073260037716f * axm - 0.2750231331124371f) + xm;
BW_ASSERT(!bw_is_nan(y));
return y;
}
static inline float bw_sinhf(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= -88.722f && x <= 88.722f);
const float y = 0.5f * (bw_expf(x) - bw_expf(-x));
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_coshf(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= -88.722f && x <= 88.722f);
const float y = 0.5f * (bw_expf(x) + bw_expf(-x));
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_asinhf(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= -8.507059173023462e+37f && x <= 8.507059173023462e+37f);
float a = bw_absf(x);
const float y = bw_copysignf(bw_logf((a >= 4096.f ? a : bw_sqrtf(a * a + 1.f)) + a), x);
BW_ASSERT(bw_is_finite(y));
return y;
}
static inline float bw_acoshf(
float x) {
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= 1.f && x <= 8.507059173023462e+37f);
const float y = bw_logf((x >= 8192.f ? x : bw_sqrtf(x * x - 1.f)) + x);
BW_ASSERT(bw_is_finite(y));
return y;
}
#ifdef __cplusplus
}
#endif
#endif