math: Use asinh from CORE-MATH

The current implementation precision shows the following accuracy, on
tthree different ranges ([-DBL_MAX, -10], [-10,10], and [10, DBL_MAX))
with 10e9 uniform randomly generated numbers for each range (first
column is the accuracy in ULP, with '0' being correctly rounded, second
is the number of samples with the corresponding precision):

* range [-DBL_MAX, -10]
 * FE_TONEAREST
     0:       5164019099  51.64%
     1:       4835980901  48.36%
 * FE_UPWARD
     1:       4836053540  48.36%
     2:       5163946460  51.64%
 * FE_DOWNWARD
     1:       5163926134  51.64%
     2:       4836073866  48.36%
 * FE_TOWARDZERO
     0:       5163937001  51.64%
     1:       4836062999  48.36%

* Range [-10, 10)
 * FE_TONEAREST
     0:       8679029381  86.79%
     1:       1320934581  13.21%
     2:            36038   0.00%
 * FE_UPWARD
     0:       3965704277  39.66%
     1:       4993616710  49.94%
     2:       1039680225  10.40%
     3:           998788   0.01%
 * FE_DOWNWARD
     0:       3965806523  39.66%
     1:       4993534438  49.94%
     2:       1039601726  10.40%
     3:          1057313   0.01%
 * FE_TOWARDZEROA
     0:       7734210130  77.34%
     1:       2261868439  22.62%
     2:          3921431   0.04%

* Range [10, DBL_MAX)
 * FE_TONEAREST
     0:       5163973212  51.64%
     1:       4836026788  48.36%
 * FE_UPWARD
     0:       4835991071  48.36%
     1:       5164008929  51.64%
 * FE_DOWNWARD
     0:       5163983594  51.64%
     1:       4836016406  48.36%
 * FE_TOWARDZERO
     0:       5163993394  51.64%
     1:       4836006606  48.36%

The CORE-MATH implementation is correctly rounded for any rounding mode.
The code was adapted to glibc style and to use the definition of
math_config.h (to handle errno, overflow, and underflow).

Benchtest on x64_64 (Ryzen 9 5900X, gcc 14.2.1), aarch64 (Neoverse-N1,
gcc 13.3.1), and powerpc (POWER10, gcc 13.2.1) shows:

reciprocal-throughput        master        patched   improvement
x86_64                      26.5178        45.3754       -71.11%
x86_64v2                    26.3167        44.7870       -70.18%
x86_64v3                    25.9109        25.4887         1.63%
aarch64                     18.0555        17.3374         3.98%
power10                     19.8535        20.5586        -3.55%

Latency                      master        patched   improvement
x86_64                      82.6755        91.2026       -10.31%
x86_64v2                    82.4581        90.7152       -10.01%
x86_64v3                    80.7000        71.9454        10.85%
aarch64                     32.8320        28.8565        12.11%
power10                     44.5309        37.0096        16.89%

For x86_64/x86_64-v2, most performance hit came from the fma call
through the ifunc mechanism.

Checked on x86_64-linux-gnu, aarch64-linux-gnu, and
powerpc64le-linux-gnu.

Reviewed-by: DJ Delorie <dj@redhat.com>
This commit is contained in:
Adhemerval Zanella 2025-10-10 15:15:23 -03:00
parent d1509f2ce3
commit 30e66b085c
6 changed files with 608 additions and 53 deletions

View File

@ -241,6 +241,8 @@ tzdata:
core-math:
# src/binary64/acosh/acosh.c, revision 69062c4d
sysdeps/ieee754/dbl-64/e_acosh.c
# src/binary64/asinh/asinh.c, revision fde815f8
sysdeps/ieee754/dbl-64/s_asinh.c
# src/binary32/acos/acosf.c, revision 56dd347
sysdeps/ieee754/flt-32/e_acosf.c
# src/binary32/acosh/acoshf.c, revision d0b9ddd

View File

@ -23,3 +23,16 @@ float: 1
Function: "cbrt_upward":
float: 1
# sysdeps/i386/fpu/s_asinh.S is not correctly rounded
Function: "asinh":
double: 1
Function: "asinh_downward":
double: 1
Function: "asinh_towardzero":
double: 1
Function: "asinh_upward":
double: 1

View File

@ -10,3 +10,15 @@ double: 0
Function: "acosh_upward":
double: 0
Function: "asinh":
double: 0
Function: "asinh_downward":
double: 0
Function: "asinh_towardzero":
double: 0
Function: "asinh_upward":
double: 0

View File

@ -172,6 +172,8 @@ attribute_hidden double __math_edom (double x);
attribute_hidden double __math_check_oflow (double);
/* Check if the result underflowed to 0. */
attribute_hidden double __math_check_uflow (double);
/* Check if the |X| if less than Y. */
attribute_hidden double __math_check_uflow_lt (double, double);
/* Check if the result overflowed to infinity. */
static inline double

View File

@ -79,6 +79,12 @@ __math_may_uflow (uint32_t sign)
}
#endif
attribute_hidden double
__math_always_uflow (double x)
{
return with_errno (x, ERANGE);
}
attribute_hidden double
__math_oflow (uint32_t sign)
{
@ -123,6 +129,13 @@ __math_check_uflow (double y)
return y == 0.0 ? with_errno (y, ERANGE) : y;
}
attribute_hidden double
__math_check_uflow_lt (double x, double y)
{
return fabs (x) < y ? with_errno (x, ERANGE) : x;
}
attribute_hidden double
__math_check_oflow (double y)
{

View File

@ -1,70 +1,583 @@
/* @(#)s_asinh.c 5.1 93/09/24 */
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/* Correctly-rounded inverse hyperbolic sine function. Binary64 version.
/* asinh(x)
* Method :
* Based on
* asinh(x) = sign(x) * log [ |x| + sqrt(x*x+1) ]
* we have
* asinh(x) := x if 1+x*x=1,
* := sign(x)*(log(x)+ln2)) for large |x|, else
* := sign(x)*log(2|x|+1/(|x|+sqrt(x*x+1))) if|x|>2, else
* := sign(x)*log1p(|x| + x^2/(1 + sqrt(1+x^2)))
*/
Copyright (c) 2023-2025 Alexei Sibidanov.
#include <float.h>
The original version of this file was copied from the CORE-MATH
project (file src/binary64/asinh/asinh.c, revision fde815f8).
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
#include <array_length.h>
#include <stdint.h>
#include <math.h>
#include <math_private.h>
#include <math-underflow.h>
#include <libm-alias-double.h>
#include "math_config.h"
static const double
one = 1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */
ln2 = 6.93147180559945286227e-01, /* 0x3FE62E42, 0xFEFA39EF */
huge = 1.00000000000000000000e+300;
static inline double
fasttwosum (double x, double y, double *e)
{
double s = x + y, z = s - x;
*e = y - z;
return s;
}
static inline double
adddd (double xh, double xl, double ch, double cl, double *l)
{
double s = xh + ch, d = s - xh;
*l = ((ch - d) + (xh + (d - s))) + (xl + cl);
return s;
}
static inline double
muldd (double xh, double xl, double ch, double cl, double *l)
{
double ahlh = ch * xl, alhh = cl * xh, ahhh = ch * xh,
ahhl = fma (ch, xh, -ahhh);
ahhl += alhh + ahlh;
ch = ahhh + ahhl;
*l = (ahhh - ch) + ahhl;
return ch;
}
static inline double
mulddd (double xh, double xl, double ch, double *l)
{
double ahlh = ch * xl, ahhh = ch * xh, ahhl = fma (ch, xh, -ahhh);
ahhl += ahlh;
ch = ahhh + ahhl;
*l = (ahhh - ch) + ahhl;
return ch;
}
static inline double
polydd (double xh, double xl, int n, const double c[][2], double *l)
{
int i = n - 1;
double ch = c[i][0] + *l, cl = ((c[i][0] - ch) + *l) + c[i][1];
while (--i >= 0)
{
ch = muldd (xh, xl, ch, cl, &cl);
double th = ch + c[i][0], tl = (c[i][0] - th) + ch;
ch = th;
cl += tl + c[i][1];
}
*l = cl;
return ch;
}
static double __attribute__ ((noinline)) as_asinh_refine (double, double,
double, double);
static double __attribute__ ((noinline))
as_asinh_zero (double x, double x2h, double x2l)
{
static const double ch[][2]
= { { -0x1.5555555555555p-3, -0x1.5555555555555p-57 },
{ 0x1.3333333333333p-4, 0x1.99999999949dfp-59 },
{ -0x1.6db6db6db6db7p-5, 0x1.2492496091b0cp-60 },
{ 0x1.f1c71c71c71c7p-6, 0x1.c71a35cfa0671p-62 },
{ -0x1.6e8ba2e8ba2e9p-6, 0x1.17f937248cf81p-60 },
{ 0x1.1c4ec4ec4ec4fp-6, -0x1.74e3c1dfd4c3dp-60 },
{ -0x1.c999999999977p-7, -0x1.38e7a467ecc55p-61 },
{ 0x1.7a87878786c7ep-7, 0x1.a83c7bace55ebp-61 },
{ -0x1.3fde50d764083p-7, -0x1.d024df7fa0542p-61 },
{ 0x1.12ef3ceae4d12p-7, -0x1.ba9c13deb261fp-61 },
{ -0x1.df3bd104aa267p-8, -0x1.546da9bc5b32ap-62 },
{ 0x1.a685fc5de7a04p-8, 0x1.40d284a1d67f9p-62 } };
static const double cl[]
= { -0x1.7828d553ec8p-8, 0x1.51712f7bee368p-8, -0x1.2e6d98527bcc6p-8,
0x1.0095da47b392cp-8, -0x1.3b92d6368192cp-9 };
double y2
= x2h
* (cl[0]
+ x2h * (cl[1] + x2h * (cl[2] + x2h * (cl[3] + x2h * (cl[4])))));
double y1 = polydd (x2h, x2l, 12, ch, &y2);
y1 = muldd (y1, y2, x2h, x2l, &y2);
y1 = mulddd (y1, y2, x, &y2);
double y0 = fasttwosum (x, y1, &y1);
y1 = fasttwosum (y1, y2, &y2);
uint64_t t = asuint64 (y1);
if (__glibc_unlikely (!(t & (~UINT64_C (0) >> 12))))
{
uint64_t w = asuint64 (y2);
if ((w ^ t) >> 63)
t--;
else
t++;
y1 = asdouble (t);
}
return y0 + y1;
}
static const struct
{
uint16_t c0;
short c1;
} B[] = {
{ 301, 27565 }, { 7189, 24786 }, { 13383, 22167 }, { 18923, 19696 },
{ 23845, 17361 }, { 28184, 15150 }, { 31969, 13054 }, { 35231, 11064 },
{ 37996, 9173 }, { 40288, 7372 }, { 42129, 5657 }, { 43542, 4020 },
{ 44546, 2457 }, { 45160, 962 }, { 45399, -468 }, { 45281, -1838 },
{ 44821, -3151 }, { 44032, -4412 }, { 42929, -5622 }, { 41522, -6786 },
{ 39825, -7905 }, { 37848, -8982 }, { 35602, -10020 }, { 33097, -11020 },
{ 30341, -11985 }, { 27345, -12916 }, { 24115, -13816 }, { 20661, -14685 },
{ 16989, -15526 }, { 13107, -16339 }, { 9022, -17126 }, { 4740, -17889 }
};
static const double r1[]
= { 0x1p+0, 0x1.f5076p-1, 0x1.ea4bp-1, 0x1.dfc98p-1, 0x1.d5818p-1,
0x1.cb72p-1, 0x1.c199cp-1, 0x1.b7f76p-1, 0x1.ae8ap-1, 0x1.a5504p-1,
0x1.9c492p-1, 0x1.93738p-1, 0x1.8ace6p-1, 0x1.8258ap-1, 0x1.7a114p-1,
0x1.71f76p-1, 0x1.6a09ep-1, 0x1.6247ep-1, 0x1.5ab08p-1, 0x1.5342cp-1,
0x1.4bfdap-1, 0x1.44e08p-1, 0x1.3dea6p-1, 0x1.371a8p-1, 0x1.306fep-1,
0x1.29e9ep-1, 0x1.2387ap-1, 0x1.1d488p-1, 0x1.172b8p-1, 0x1.11302p-1,
0x1.0b558p-1, 0x1.059bp-1, 0x1p-1 };
static const double r2[]
= { 0x1p+0, 0x1.ffa74p-1, 0x1.ff4eap-1, 0x1.fef62p-1, 0x1.fe9dap-1,
0x1.fe452p-1, 0x1.fdeccp-1, 0x1.fd946p-1, 0x1.fd3c2p-1, 0x1.fce3ep-1,
0x1.fc8bcp-1, 0x1.fc33ap-1, 0x1.fbdbap-1, 0x1.fb83ap-1, 0x1.fb2bcp-1,
0x1.fad3ep-1, 0x1.fa7c2p-1, 0x1.fa246p-1, 0x1.f9ccap-1, 0x1.f975p-1,
0x1.f91d8p-1, 0x1.f8c6p-1, 0x1.f86e8p-1, 0x1.f8172p-1, 0x1.f7bfep-1,
0x1.f768ap-1, 0x1.f7116p-1, 0x1.f6ba4p-1, 0x1.f6632p-1, 0x1.f60c2p-1,
0x1.f5b52p-1, 0x1.f55e4p-1, 0x1.f5076p-1 };
static const double l1[][2] = { { 0x0p+0, 0x0p+0 },
{ -0x1.269e2038315b3p-46, 0x1.62e4eacd4p-6 },
{ -0x1.3f2558bddfc47p-45, 0x1.62e3ce7218p-5 },
{ 0x1.07ea13c34efb5p-45, 0x1.0a2ab6d3ecp-4 },
{ 0x1.8f3e77084d3bap-44, 0x1.62e4a86d8cp-4 },
{ -0x1.8d92a005f1a7ep-46, 0x1.bb9db7062cp-4 },
{ 0x1.58239e799bfe5p-44, 0x1.0a2b1a22ccp-3 },
{ -0x1.a93fcf5f593b7p-44, 0x1.3687f0a298p-3 },
{ -0x1.db4cac32fd2b5p-46, 0x1.62e4116b64p-3 },
{ -0x1.0e65a92ee0f3bp-46, 0x1.8f409e4df6p-3 },
{ -0x1.8261383d475f1p-44, 0x1.bb9d15001cp-3 },
{ -0x1.359886207513bp-44, 0x1.e7f9a8c94p-3 },
{ 0x1.811f87496ceb7p-44, 0x1.0a2b052ddbp-2 },
{ 0x1.4991ec6cb435cp-44, 0x1.205955ef73p-2 },
{ -0x1.4581abfeb8927p-44, 0x1.3687bd9121p-2 },
{ 0x1.cab48f6942703p-44, 0x1.4cb5e8f2b5p-2 },
{ -0x1.df2c452fde132p-47, 0x1.62e4420e2p-2 },
{ 0x1.6109f4fdb74bdp-45, 0x1.791292c46ap-2 },
{ -0x1.6b95fbdac7696p-44, 0x1.8f40af84e7p-2 },
{ 0x1.7394fa880cbdap-46, 0x1.a56ed8f865p-2 },
{ -0x1.50b06a94eccabp-46, 0x1.bb9d6505b4p-2 },
{ -0x1.be2abf0b38989p-44, 0x1.d1cb91e728p-2 },
{ -0x1.7d6bf1e34da04p-44, 0x1.e7f9d139e2p-2 },
{ -0x1.423c1e14de6edp-44, 0x1.fe27db9b0ep-2 },
{ 0x1.c46f1a0efbbc2p-44, 0x1.0a2b25060a8p-1 },
{ 0x1.834fe4e3e6018p-45, 0x1.154244482ap-1 },
{ 0x1.6a03d0f02b65p-46, 0x1.20597312988p-1 },
{ 0x1.d437056526f3p-44, 0x1.2b707145dep-1 },
{ -0x1.a0233728405c5p-45, 0x1.3687b0e0b28p-1 },
{ -0x1.4dbdda10d2bf1p-45, 0x1.419ec5d3f68p-1 },
{ 0x1.f7d0a25d154f2p-44, 0x1.4cb5f9fc02p-1 },
{ 0x1.15ede4d803b18p-44, 0x1.57cd28421a8p-1 },
{ 0x1.ef35793c7673p-45, 0x1.62e42fefa38p-1 } };
static const double l2[][2] = { { 0x0p+0, 0x0p+0 },
{ 0x1.5abdac3638e99p-44, 0x1.631ec81ep-11 },
{ -0x1.16b8be9bbe239p-45, 0x1.62fd8127p-10 },
{ -0x1.364c6315542ebp-44, 0x1.0a2520508p-9 },
{ 0x1.734abe459c9p-45, 0x1.62dadc1dp-9 },
{ 0x1.0cf8a761431bfp-44, 0x1.bb9ff94dp-9 },
{ 0x1.da2718eb78708p-45, 0x1.0a2a2def8p-8 },
{ 0x1.34ada62c59b93p-44, 0x1.368c0fae4p-8 },
{ 0x1.d09ab376682d4p-44, 0x1.62e58e4f8p-8 },
{ -0x1.3cb7b94329211p-45, 0x1.8f46bd28cp-8 },
{ -0x1.eec5c297c41dp-45, 0x1.bb9f8312p-8 },
{ -0x1.6411b9395d15p-44, 0x1.e7fff8f3p-8 },
{ -0x1.1c0e59a43053cp-44, 0x1.0a2c0006ep-7 },
{ 0x1.6506596e077b6p-46, 0x1.205bdb6fp-7 },
{ 0x1.e256bce6faa27p-44, 0x1.36877c86ep-7 },
{ 0x1.bd42467b0c8d1p-51, 0x1.4cb6f5578p-7 },
{ -0x1.c4f92132ff0fp-44, 0x1.62e230e8cp-7 },
{ -0x1.80be08bfab39p-44, 0x1.7911440f6p-7 },
{ -0x1.f0b1319ceb1f7p-44, 0x1.8f443020ap-7 },
{ 0x1.a65fcfb8de99bp-45, 0x1.a572dbef4p-7 },
{ 0x1.4233885d3779cp-46, 0x1.bb9d449a6p-7 },
{ 0x1.f46a59e646edbp-44, 0x1.d1cb8491cp-7 },
{ -0x1.c3d2f11c11446p-44, 0x1.e7fd9d2aap-7 },
{ 0x1.7763f78a1e0ccp-45, 0x1.fe2b6f978p-7 },
{ 0x1.b4c37fc60c043p-44, 0x1.0a2a7c7a5p-6 },
{ -0x1.5b8a822859be3p-46, 0x1.15412ca86p-6 },
{ -0x1.f2d8c9fc064p-44, 0x1.2059c9005p-6 },
{ -0x1.e80e79c20378dp-44, 0x1.2b703f49bp-6 },
{ 0x1.68256e4329bdbp-44, 0x1.3688a1a8dp-6 },
{ 0x1.7e9741da248c3p-44, 0x1.419edc7bap-6 },
{ 0x1.e330dccce602bp-45, 0x1.4cb7034fap-6 },
{ 0x1.2f32b5d18eefbp-49, 0x1.57cd01187p-6 },
{ -0x1.269e2038315b3p-46, 0x1.62e4eacd4p-6 } };
static const double c[] = { -0x1p-1, 0x1.555555555553p-2, -0x1.fffffffffffap-3,
0x1.99999e33a6366p-3, -0x1.555559ef9525fp-3 };
double
__asinh (double x)
{
double w;
int32_t hx, ix;
GET_HIGH_WORD (hx, x);
ix = hx & 0x7fffffff;
if (__glibc_unlikely (ix < 0x3e300000)) /* |x|<2**-28 */
{
math_check_force_underflow (x);
if (huge + x > one)
return x; /* return x inexact except 0 */
double ax = fabs (x);
uint64_t u = asuint64 (ax);;
if (__glibc_unlikely (u < UINT64_C (0x3fbb000000000000)))
{ // |x| < 0x1.bp-4
// for |x| < 0x1.7137449123ef7p-26, asinh(x) rounds to x to nearest
// for |x| < 0x1p-1022 we have underflow but not for 0x1p-1022 (to
// nearest)
if (__glibc_unlikely (u < UINT64_C (0x3e57137449123ef7)))
{ // |x| < 0x1.7137449123ef7p-26
if (__glibc_unlikely (!u))
return x;
double res = fma (-0x1p-60, x, x);
return __math_check_uflow_lt (res, 0x1p-1022);
}
double x2h = x * x, x2l = fma (x, x, -x2h);
double x3h = x2h * x, sl;
if (__glibc_unlikely (u < UINT64_C (0x3f93000000000000)))
{ // |x| < 0x1.3p-6
if (__glibc_unlikely (u < UINT64_C (0x3f30000000000000)))
{ // |x| < 0x1p-12
if (__glibc_unlikely (u < UINT64_C (0x3e5a000000000000)))
{ // |x| < 0x1.ap-26
static const double cl[] = { -0x1.5555555555555p-3 };
sl = x3h * cl[0];
}
else
{
static const double cl[]
= { -0x1.5555555555555p-3, 0x1.3333327c57c6p-4 };
sl = x3h * (cl[0] + x2h * cl[1]);
}
}
else
{
static const double cl[]
= { -0x1.5555555555555p-3, 0x1.333333332f2ffp-4,
-0x1.6db6d9a665159p-5, 0x1.f186866d775fp-6 };
sl = x3h * (cl[0] + x2h * (cl[1] + x2h * (cl[2] + x2h * cl[3])));
}
}
else
{
static const double cl[]
= { -0x1.5555555555555p-3, 0x1.333333333331p-4,
-0x1.6db6db6da466cp-5, 0x1.f1c71c2ea7be4p-6,
-0x1.6e8b651b09d72p-6, 0x1.1c309fc0e69c2p-6,
-0x1.bab7833c1ep-7 };
double c1 = cl[1] + x2h * cl[2];
double c3 = cl[3] + x2h * cl[4];
double c5 = cl[5] + x2h * cl[6];
double x4 = x2h * x2h;
sl = x3h * (cl[0] + x2h * (c1 + x4 * (c3 + x4 * c5)));
}
double eps = 0x1.6p-53 * x3h;
double lb = x + (sl - eps), ub = x + (sl + eps);
if (lb == ub)
return lb;
return as_asinh_zero (x, x2h, x2l);
}
if (__glibc_unlikely (ix > 0x41b00000)) /* |x| > 2**28 */
// |x| >= 0x1.bp-4
double x2h = 0, x2l = 0;
double ah, al;
int off = 0x3ff;
if (__glibc_likely (u < UINT64_C (0x4190000000000000)))
{ // x < 0x1p+26
double th, tl;
x2h = x * x;
x2l = fma (x, x, -x2h);
if (__glibc_unlikely (u < UINT64_C (0x3ff0000000000000)))
th = fasttwosum (1, x2h, &tl);
else
th = fasttwosum (x2h, 1, &tl);
tl += x2l;
ah = sqrt (th);
double rs = 0.5 / th;
al = (tl - fma (ah, ah, -th)) * (rs * ah);
ah = fasttwosum (ah, ax, &tl);
al += tl;
}
else if (u < UINT64_C (0x4330000000000000))
{
if (ix >= 0x7ff00000)
return x + x; /* x is inf or NaN */
w = __ieee754_log (fabs (x)) + ln2;
ah = 2 * ax;
al = 0.5 / ax;
}
else
{
double xa = fabs (x);
if (ix > 0x40000000) /* 2**28 > |x| > 2.0 */
{
w = __ieee754_log (2.0 * xa + one / (sqrt (xa * xa + one) +
xa));
}
else /* 2.0 > |x| > 2**-28 */
{
double t = xa * xa;
w = __log1p (xa + t / (one + sqrt (one + t)));
}
if (__glibc_unlikely (u >= UINT64_C (0x7ff0000000000000)))
return x + x; // +-inf or nan
off = 0x3fe;
ah = ax;
al = 0;
}
return copysign (w, x);
uint64_t t = asuint64 (ah);
int ex = t >> 52, e = ex - off;
t &= ~UINT64_C (0) >> 12;
double ed = e;
uint64_t i = t >> (52 - 5);
int64_t d = t & (~UINT64_C (0) >> 17);
uint64_t j
= (t + ((uint64_t) B[i].c0 << 33) + ((int64_t) B[i].c1 * (d >> 16)))
>> (52 - 10);
t |= UINT64_C (0x3ff) << 52;
int i1 = j >> 5, i2 = j & 0x1f;
double r = r1[i1] * r2[i2], dx = fma (r, asdouble (t), -1), dx2 = dx * dx;
double f
= dx2 * ((c[0] + dx * c[1]) + dx2 * ((c[2] + dx * c[3]) + dx2 * c[4]));
const double l2h = 0x1.62e42fefa38p-1, l2l = 0x1.ef35793c7673p-45;
double lh = l2h * ed + (l1[i1][1] + l2[i2][1]);
double ll = l2l * ed + l1[i1][0] + l2[i2][0] + al / ah + f;
ll += dx;
lh *= copysign (1, x);
ll *= copysign (1, x);
double eps = 1.63e-19;
double lb = lh + (ll - eps), ub = lh + (ll + eps);
if (lb == ub)
return lb;
if (ax < 0x1p-2)
return as_asinh_zero (x, x2h, x2l);
return as_asinh_refine (x, ah, al,
0x1.71547652b82fep+0 * fabs (lb));
}
libm_alias_double (__asinh, asinh)
static __attribute__ ((noinline)) double
as_asinh_database (double x, double f)
{
static const double db[][3] = {
{ 0x1.00f9476450863p-2, 0x1.fcb35067f343cp-3, 0x1p-57 },
{ 0x1.1f0a79315b287p-2, 0x1.1b68aae88febap-2, 0x1p-56 },
{ 0x1.2b9618ff7acb7p-2, 0x1.27781d9aa4e25p-2, -0x1p-56 },
{ 0x1.389ef683f3aa7p-2, 0x1.33f52db6df1afp-2, 0x1p-56 },
{ 0x1.3b07e0c779ddap-2, 0x1.364303e1ad8f6p-2, 0x1p-56 },
{ 0x1.48441df33b6d3p-2, 0x1.42e385800f0a4p-2, 0x1p-56 },
{ 0x1.687bd068c1c1ep-2, 0x1.616cc75d49226p-2, -0x1p-56 },
{ 0x1.8740c4453a056p-2, 0x1.7e4f2ad132a1dp-2, 0x1p-56 },
{ 0x1.891acda11167ep-2, 0x1.8009d924a3ffdp-2, 0x1p-56 },
{ 0x1.bafc3479fc9ccp-2, 0x1.ae3773250e7d2p-2, 0x1p-56 },
{ 0x1.c59869f17b483p-2, 0x1.b7efa91915c95p-2, 0x1p-56 },
{ 0x1.c8be879787986p-2, 0x1.bad0485e0fe0ap-2, -0x1p-56 },
{ 0x1.e73b46abb01e1p-2, 0x1.d68039861ab53p-2, 0x1p-56 },
{ 0x1.ed6236da268bp-2, 0x1.dc0cb8f638126p-2, 0x1p-56 },
{ 0x1.f399ebafc1951p-2, 0x1.e1a4f519fab77p-2, -0x1p-56 },
{ 0x1.f70975ab0d471p-2, 0x1.e4bae8bcd6ea6p-2, 0x1p-56 },
{ 0x1.fbdd4a37760b7p-2, 0x1.e90f16eb88c09p-2, 0x1p-56 },
{ 0x1.fee72efb4bfddp-2, 0x1.ebc791a88bed8p-2, 0x1p-56 },
{ 0x1.02339d6bdb741p-1, 0x1.f0b2264e34555p-2, 0x1p-56 },
{ 0x1.09e7c831b1a23p-1, 0x1.fe694c3c89138p-2, 0x1p-56 },
{ 0x1.16d32c862fc3bp-1, 0x1.0a9c9334066dbp-1, -0x1p-55 },
{ 0x1.857954132083dp-1, 0x1.67425fe575c88p-1, -0x1p-55 },
{ 0x1.8a5c3b60f7e11p-1, 0x1.6b23ad4415a17p-1, -0x1p-55 },
{ 0x1.9740eb419dd04p-1, 0x1.754ab7535d47dp-1, 0x1p-55 },
{ 0x1.a16d9cc06011ap-1, 0x1.7d3755d851062p-1, -0x1p-55 },
{ 0x1.bb635be2213d1p-1, 0x1.91167cae3cfa9p-1, 0x1p-55 },
{ 0x1.d4b21ebf542fp-1, 0x1.a3fc7e4dd47d1p-1, -0x1p-55 },
{ 0x1.7b8516ffd2406p+0, 0x1.2f5d3b178914ap+0, 0x1p-54 },
{ 0x1.9295b9116e2e2p+0, 0x1.3bffa8863976p+0, 0x1p-54 },
{ 0x1.fedc65e32714p+0, 0x1.710f91e844f9bp+0, 0x1p-54 },
{ 0x1.57e377b3f0b4bp+1, 0x1.b6e2c73f41415p+0, 0x1p-54 },
{ 0x1.6056b06a21918p+3, 0x1.8c0a26d055288p+1, 0x1p-53 },
{ 0x1.843e1b5e5979cp+4, 0x1.f0f978201eb84p+1, 0x1p-53 },
{ 0x1.fee8f69c4cd25p+10, 0x1.0a19aebb51e9p+3, -0x1p-51 },
{ 0x1.0fbc6c02b1c9p+24, 0x1.16369cd53bb69p+4, 0x1p-50 },
};
double ax = fabs (x);
int a = 0, b = array_length (db) - 1, m = (a + b) / 2;
while (a <= b)
{ // binary search
if (db[m][0] < ax)
a = m + 1;
else if (db[m][0] == ax)
{
double sgn = copysign (1, x);
f = sgn * db[m][1] + sgn * db[m][2];
break;
}
else
b = m - 1;
m = (a + b) / 2;
}
return f;
}
static double
as_asinh_refine (double x, double zh, double zl, double a)
{
static const double t1[]
= { 0x1p+0, 0x1.ea4afap-1, 0x1.d5818ep-1, 0x1.c199bep-1,
0x1.ae89f98p-1, 0x1.9c4918p-1, 0x1.8ace54p-1, 0x1.7a1147p-1,
0x1.6a09e68p-1, 0x1.5ab07ep-1, 0x1.4bfdad8p-1, 0x1.3dea65p-1,
0x1.306fe08p-1, 0x1.2387a7p-1, 0x1.172b84p-1, 0x1.0b5587p-1,
0x1p-1 };
static const double t2[]
= { 0x1p+0, 0x1.fe9d968p-1, 0x1.fd3c228p-1, 0x1.fbdba38p-1,
0x1.fa7c18p-1, 0x1.f91d8p-1, 0x1.f7bfdbp-1, 0x1.f663278p-1,
0x1.f507658p-1, 0x1.f3ac948p-1, 0x1.f252b38p-1, 0x1.f0f9c2p-1,
0x1.efa1bfp-1, 0x1.ee4aaap-1, 0x1.ecf483p-1, 0x1.eb9f488p-1 };
static const double t3[]
= { 0x1p+0, 0x1.ffe9d2p-1, 0x1.ffd3a58p-1, 0x1.ffbd798p-1,
0x1.ffa74e8p-1, 0x1.ff91248p-1, 0x1.ff7afb8p-1, 0x1.ff64d38p-1,
0x1.ff4eac8p-1, 0x1.ff38868p-1, 0x1.ff22618p-1, 0x1.ff0c3dp-1,
0x1.fef61ap-1, 0x1.fedff78p-1, 0x1.fec9d68p-1, 0x1.feb3b6p-1 };
static const double t4[]
= { 0x1p+0, 0x1.fffe9dp-1, 0x1.fffd3ap-1, 0x1.fffbd78p-1,
0x1.fffa748p-1, 0x1.fff9118p-1, 0x1.fff7ae8p-1, 0x1.fff64cp-1,
0x1.fff4e9p-1, 0x1.fff386p-1, 0x1.fff2238p-1, 0x1.fff0c08p-1,
0x1.ffef5d8p-1, 0x1.ffedfa8p-1, 0x1.ffec98p-1, 0x1.ffeb35p-1 };
static const double LL[4][17][3] = {
{
{ 0x0p+0, 0x0p+0, 0x0p+0 },
{ 0x1.62e432b24p-6, -0x1.745af34bb54b8p-42, -0x1.17e3ec05cde7p-97 },
{ 0x1.62e42e4a8p-5, 0x1.111a4eadf312p-44, 0x1.cff3027abb119p-93 },
{ 0x1.0a2b233f1p-4, -0x1.88ac4ec78af8p-42, 0x1.4fa087ca75dfdp-93 },
{ 0x1.62e43056cp-4, 0x1.6bd65e8b0b7p-46, -0x1.b18e160362c24p-95 },
{ 0x1.bb9d3cbd6p-4, 0x1.de14aa55ec2bp-42, -0x1.c6ac3f1862a6bp-94 },
{ 0x1.0a2b244dap-3, 0x1.94def487fea7p-42, -0x1.dead1a4581acfp-94 },
{ 0x1.3687aa9b78p-3, 0x1.9cec9a50db22p-43, 0x1.34a70684f8e0ep-93 },
{ 0x1.62e42fabap-3, -0x1.d69047a3aebp-44, -0x1.4e061f79144e2p-95 },
{ 0x1.8f40b56d28p-3, 0x1.de7d755fd2e2p-42, 0x1.bdc7ecf001489p-94 },
{ 0x1.bb9d3b61fp-3, 0x1.c14f1445b12p-46, 0x1.a1d78cbdc5b58p-93 },
{ 0x1.e7f9c11f08p-3, -0x1.6e3e0000dae7p-43, 0x1.6a4559fadde98p-94 },
{ 0x1.0a2b242ec4p-2, 0x1.bb7cf852a5fe8p-42, 0x1.a6aef11ee43bdp-93 },
{ 0x1.205966c764p-2, 0x1.ad3a5f214294p-45, 0x1.5cc344fa10652p-93 },
{ 0x1.3687a98aacp-2, 0x1.1623671842fp-45, -0x1.0b428fe1f9e43p-94 },
{ 0x1.4cb5ec93f4p-2, 0x1.3d50980ea513p-42, 0x1.67f0ea083b1c4p-93 },
{ 0x1.62e42fefa4p-2, -0x1.8432a1b0e264p-44, 0x1.803f2f6af40f3p-93 },
},
{
{ 0x0p+0, 0x0p+0, 0x0p+0 },
{ 0x1.62e462b4p-10, 0x1.061d003b97318p-42, 0x1.d7faee66a2e1ep-93 },
{ 0x1.62e44c92p-9, 0x1.95a7bff5e239p-42, -0x1.f7e788a87135p-95 },
{ 0x1.0a2b1e33p-8, 0x1.2a3a1a65aa3ap-43, -0x1.54599c9605442p-93 },
{ 0x1.62e4367cp-8, -0x1.4a995b6d9ddcp-45, -0x1.56bb79b254f33p-100 },
{ 0x1.bb9d449ap-8, 0x1.8a119c42e9bcp-42, -0x1.8ecf7d8d661f1p-93 },
{ 0x1.0a2b1f19p-7, 0x1.8863771bd10a8p-42, 0x1.e9731de7f0155p-94 },
{ 0x1.3687ad11p-7, 0x1.e026a347ca1c8p-42, 0x1.fadc62522444dp-97 },
{ 0x1.62e436f28p-7, 0x1.25b84f71b70b8p-42, -0x1.fcb3f98612d27p-96 },
{ 0x1.8f40b7b38p-7, -0x1.62a0a4fd4758p-43, 0x1.3cb3c35d9f6a1p-93 },
{ 0x1.bb9d3abbp-7, -0x1.0ec48f94d786p-42, -0x1.6b47d410e4cc7p-93 },
{ 0x1.e7f9bb23p-7, 0x1.e4415cbc97ap-43, -0x1.3729fdb677231p-93 },
{ 0x1.0a2b22478p-6, -0x1.cb73f4505b03p-42, -0x1.1b3b3a3bc370ap-93 },
{ 0x1.2059691e8p-6, -0x1.abcc3412f264p-43, -0x1.fe6e998e48673p-95 },
{ 0x1.3687a768p-6, -0x1.43901e5c97a9p-42, 0x1.b54cdd52a5d88p-96 },
{ 0x1.4cb5eb5d8p-6, -0x1.8f106f00f13b8p-42, -0x1.8f793f5fce148p-93 },
{ 0x1.62e432b24p-6, -0x1.745af34bb54b8p-42, -0x1.17e3ec05cde7p-97 },
},
{
{ 0x0p+0, 0x0p+0, 0x0p+0 },
{ 0x1.62e7bp-14, -0x1.868625640a68p-44, -0x1.34bf0db910f65p-93 },
{ 0x1.62e35f6p-13, -0x1.2ee3d96b696ap-43, 0x1.a2948cd558655p-94 },
{ 0x1.0a2b4b2p-12, 0x1.53edbcf1165p-47, -0x1.cfc26ccf6d0e4p-97 },
{ 0x1.62e4be1p-12, 0x1.783e334614p-52, -0x1.04b96da30e63ap-93 },
{ 0x1.bb9e085p-12, -0x1.60785f20acb2p-43, -0x1.f33369bf7dff1p-96 },
{ 0x1.0a2b94dp-11, 0x1.fd4b3a273353p-42, -0x1.685a35575eff1p-96 },
{ 0x1.368810f8p-11, 0x1.7ded26dc813p-47, -0x1.4c4d1abca79bfp-96 },
{ 0x1.62e47878p-11, 0x1.7d2bee9a1f63p-42, 0x1.860233b7ad13p-93 },
{ 0x1.8f40cb48p-11, -0x1.af034eaf471cp-42, 0x1.ae748822d57b7p-94 },
{ 0x1.bb9d094p-11, -0x1.7a223013a20fp-42, -0x1.1e499087075b6p-93 },
{ 0x1.e7fa32c8p-11, -0x1.b2e67b1b59bdp-43, -0x1.54a41eda30fa6p-93 },
{ 0x1.0a2b237p-10, -0x1.7ad97ff4ac7ap-44, 0x1.f932da91371ddp-93 },
{ 0x1.2059a338p-10, -0x1.96422d90df4p-44, -0x1.90800fbbf2ed3p-94 },
{ 0x1.36879824p-10, 0x1.0f9054001812p-44, 0x1.9567e01e48f9ap-93 },
{ 0x1.4cb602cp-10, -0x1.0d709a5ec0b5p-43, 0x1.253dfd44635d2p-94 },
{ 0x1.62e462b4p-10, 0x1.061d003b97318p-42, 0x1.d7faee66a2e1ep-93 },
},
{
{ 0x0p+0, 0x0p+0, 0x0p+0 },
{ 0x1.63007cp-18, -0x1.db0e38e5aaaap-43, 0x1.259a7b94815b9p-93 },
{ 0x1.6300f6p-17, 0x1.2b1c75580438p-44, 0x1.78cabba01e3e4p-93 },
{ 0x1.0a2115p-16, -0x1.5ff223730759p-42, 0x1.8074feacfe49dp-95 },
{ 0x1.62e1ecp-16, -0x1.85d6f6487ce4p-45, 0x1.05485074b9276p-93 },
{ 0x1.bba301p-16, -0x1.af5d58a7c921p-43, -0x1.30a8c0fd2ff5fp-93 },
{ 0x1.0a32298p-15, 0x1.590faa0883bdp-43, 0x1.95e9bda999947p-93 },
{ 0x1.3682f1p-15, 0x1.f0224376efaf8p-42, -0x1.5843c0db50d1p-93 },
{ 0x1.62e3d8p-15, -0x1.142c13daed4ap-43, 0x1.c68a61183ce87p-93 },
{ 0x1.8f44dd8p-15, -0x1.aa489f399931p-43, 0x1.11c5c376854eap-94 },
{ 0x1.bb9601p-15, 0x1.9904d8b6a3638p-42, 0x1.8c89554493c8fp-93 },
{ 0x1.e7f744p-15, 0x1.5785ddbe7cba8p-42, 0x1.e7ff3cde7d70cp-94 },
{ 0x1.0a2c53p-14, -0x1.6d9e8780d0d5p-43, 0x1.ad9c178106693p-94 },
{ 0x1.205d134p-14, -0x1.214a2e893fccp-43, 0x1.548a9500c9822p-93 },
{ 0x1.3685e28p-14, 0x1.e23588646103p-43, 0x1.2a97b26da2d88p-94 },
{ 0x1.4cb6c18p-14, 0x1.2b7cfcea9e0d8p-42, -0x1.5095048a6b824p-93 },
{ 0x1.62e7bp-14, -0x1.868625640a68p-44, -0x1.34bf0db910f65p-93 },
},
};
static const double ch[][2] = {
{ 0x1p-1, 0x1.24b67ee516e3bp-111 },
{ -0x1p-2, -0x1.932ce43199a8dp-110 },
{ 0x1.5555555555555p-3, 0x1.55540c15cf91fp-57 },
};
static const double cl[3]
= { -0x1p-3, 0x1.9999999a0754fp-4, -0x1.55555555c3157p-4 };
uint64_t t = asuint64 (zh);
int ex = t >> 52, e = ex - 0x3ff + (zl == 0.0);
t &= ~UINT64_C (0) >> 12;
t |= UINT64_C (0x3ff) << 52;
double ed = e;
uint64_t v = asuint64 (a - ed + 0x1.00008p+0);
uint64_t i = (v - (UINT64_C (0x3ff) << 52)) >> (52 - 16);
int i1 = (i >> 12) & 0x1f, i2 = (i >> 8) & 0xf, i3 = (i >> 4) & 0xf,
i4 = i & 0xf;
const double l20 = 0x1.62e42fefa38p-2, l21 = 0x1.ef35793c768p-46,
l22 = -0x1.9ff0342542fc3p-91;
double el2 = l22 * ed, el1 = l21 * ed, el0 = l20 * ed;
double L[3];
L[0] = LL[0][i1][0] + LL[1][i2][0] + (LL[2][i3][0] + LL[3][i4][0]);
L[1] = LL[0][i1][1] + LL[1][i2][1] + (LL[2][i3][1] + LL[3][i4][1]);
L[2] = LL[0][i1][2] + LL[1][i2][2] + (LL[2][i3][2] + LL[3][i4][2]);
L[0] += el0;
double t12 = t1[i1] * t2[i2], t34 = t3[i3] * t4[i4];
double th = t12 * t34, tl = fma (t12, t34, -th);
double tf = asdouble (t);
double dh = th * tf, dl = fma (th, tf, -dh);
double sh = tl * tf, sl = fma (tl, tf, -sh);
double xl, xh = fasttwosum (dh - 1, dl, &xl);
if (zl != 0.0)
{
t = asuint64 (zl);
t -= (int64_t) e << 52;
xl += th * asdouble (t);
}
xh = adddd (xh, xl, sh, sl, &xl);
sl = xh * (cl[0] + xh * (cl[1] + xh * cl[2]));
sh = polydd (xh, xl, 3, ch, &sl);
sh = muldd (xh, xl, sh, sl, &sl);
sh = adddd (sh, sl, el1, el2, &sl);
sh = adddd (sh, sl, L[1], L[2], &sl);
double v2, v0 = fasttwosum (L[0], sh, &v2);
double v1 = fasttwosum (v2, sl, &v2);
v0 *= copysign (2, x);
v1 *= copysign (2, x);
v2 *= copysign (2, x);
t = asuint64 (v1);
if (__glibc_unlikely (!(t & (~UINT64_C (0) >> 12))))
{
uint64_t w = asuint64 (v2);
if ((w ^ t) >> 63)
t--;
else
t++;
v1 = asdouble (t);
}
uint64_t t0 = asuint64 (v0);
uint64_t er = ((t + 33) & (~UINT64_C (0) >> 12)),
de = ((t0 >> 52) & 0x7ff) - ((t >> 52) & 0x7ff);
double res = v0 + v1;
if (__glibc_unlikely (de > 99 || er < 66))
return as_asinh_database (x, res);
return res;
}