mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-21 12:30:06 +00:00
math: Use log10f from CORE-MATH
The CORE-MATH implementation is correctly rounded (for any rounding mode)
and shows better performance compared to the generic log10f.
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):
Latency master patched improvement
x86_64 49.9017 33.5143 32.84%
x86_64v2 50.4878 33.5623 33.52%
x86_64v3 50.0991 27.6078 44.89%
i686 140.874 106.086 24.69%
aarch64 19.2846 11.3573 41.11%
power10 14.0994 7.7739 44.86%
powerpc 14.2898 7.92497 44.54%
reciprocal-throughput master patched improvement
x86_64 17.8336 12.9074 27.62%
x86_64v2 16.4418 11.3220 31.14%
x86_64v3 15.6002 10.5158 32.59%
i686 66.0678 80.2287 -21.43%
aarch64 9.4906 6.8393 27.94%
power10 7.5255 5.5084 26.80%
powerpc 9.5204 6.98055 26.68%
The performance decrease for i686 is mostly due the use of x87 fpu,
when building with '-msse2 -mfpmath=sse':
master patched improvement
latency 140.874 77.1137 45.26%
reciprocal-throughput 64.481 56.4397 12.47%
Signed-off-by: Alexei Sibidanov <sibid@uvic.ca>
Signed-off-by: Paul Zimmermann <Paul.Zimmermann@inria.fr>
Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: DJ Delorie <dj@redhat.com>
This commit is contained in:
Adhemerval Zanella
parent
bbd578b38d
commit
9247f53219
@ -252,3 +252,7 @@ sysdeps/ieee754/flt-32/s_expm1f.c
|
||||
(file src/binary32/expm1/expm1f.c in CORE-MATH)
|
||||
- The code was adapted to use glibc code style and internal
|
||||
functions to handle errno, overflow, and underflow.
|
||||
sysdeps/ieee754/flt-32/e_log10f.c
|
||||
(file src/binary32/log10/log10f.c in CORE-MATH)
|
||||
- The code was adapted to use glibc code style and internal
|
||||
functions to handle errno, overflow, and underflow.
|
||||
|
||||
@ -1,66 +0,0 @@
|
||||
/*
|
||||
* Public domain.
|
||||
*/
|
||||
|
||||
#include <machine/asm.h>
|
||||
#include <libm-alias-finite.h>
|
||||
|
||||
.section .rodata.cst8,"aM",@progbits,8
|
||||
|
||||
.p2align 3
|
||||
.type one,@object
|
||||
one: .double 1.0
|
||||
ASM_SIZE_DIRECTIVE(one)
|
||||
/* It is not important that this constant is precise. It is only
|
||||
a value which is known to be on the safe side for using the
|
||||
fyl2xp1 instruction. */
|
||||
.type limit,@object
|
||||
limit: .double 0.29
|
||||
ASM_SIZE_DIRECTIVE(limit)
|
||||
|
||||
|
||||
#ifdef PIC
|
||||
# define MO(op) op##@GOTOFF(%edx)
|
||||
#else
|
||||
# define MO(op) op
|
||||
#endif
|
||||
|
||||
.text
|
||||
ENTRY(__ieee754_log10f)
|
||||
fldlg2 // log10(2)
|
||||
flds 4(%esp) // x : log10(2)
|
||||
#ifdef PIC
|
||||
LOAD_PIC_REG (dx)
|
||||
#endif
|
||||
fxam
|
||||
fnstsw
|
||||
fld %st // x : x : log10(2)
|
||||
sahf
|
||||
jc 3f // in case x is NaN or ±Inf
|
||||
4: fsubl MO(one) // x-1 : x : log10(2)
|
||||
fld %st // x-1 : x-1 : x : log10(2)
|
||||
fabs // |x-1| : x-1 : x : log10(2)
|
||||
fcompl MO(limit) // x-1 : x : log10(2)
|
||||
fnstsw // x-1 : x : log10(2)
|
||||
andb $0x45, %ah
|
||||
jz 2f
|
||||
fxam
|
||||
fnstsw
|
||||
andb $0x45, %ah
|
||||
cmpb $0x40, %ah
|
||||
jne 5f
|
||||
fabs // log10(1) is +0 in all rounding modes.
|
||||
5: fstp %st(1) // x-1 : log10(2)
|
||||
fyl2xp1 // log10(x)
|
||||
ret
|
||||
|
||||
2: fstp %st(0) // x : log10(2)
|
||||
fyl2x // log10(x)
|
||||
ret
|
||||
|
||||
3: jp 4b // in case x is ±Inf
|
||||
fstp %st(1)
|
||||
fstp %st(1)
|
||||
ret
|
||||
END (__ieee754_log10f)
|
||||
libm_alias_finite (__ieee754_log10f, __log10f)
|
||||
@ -1,54 +1,162 @@
|
||||
/* e_log10f.c -- float version of e_log10.c.
|
||||
*/
|
||||
/* Correctly-rounded radix-10 logarithm function for binary32 value.
|
||||
|
||||
/*
|
||||
* ====================================================
|
||||
* 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.
|
||||
* ====================================================
|
||||
*/
|
||||
Copyright (c) 2022-2023 Alexei Sibidanov.
|
||||
|
||||
This file is part of the CORE-MATH project
|
||||
project (file src/binary32/log10/log10f.c, revision bc385c2).
|
||||
|
||||
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 <math.h>
|
||||
#include <math_private.h>
|
||||
#include <fix-int-fp-convert-zero.h>
|
||||
#include <stdint.h>
|
||||
#include <libm-alias-finite.h>
|
||||
#include "math_config.h"
|
||||
|
||||
static const float
|
||||
two25 = 3.3554432000e+07, /* 0x4c000000 */
|
||||
ivln10 = 4.3429449201e-01, /* 0x3ede5bd9 */
|
||||
log10_2hi = 3.0102920532e-01, /* 0x3e9a2080 */
|
||||
log10_2lo = 7.9034151668e-07; /* 0x355427db */
|
||||
static __attribute__ ((noinline)) float
|
||||
as_special (float x)
|
||||
{
|
||||
uint32_t ux = asuint (x);
|
||||
if (ux == 0x7f800000u)
|
||||
return x; /* +inf */
|
||||
uint32_t ax = ux << 1;
|
||||
if (ax == 0u)
|
||||
{ /* -0.0 */
|
||||
__math_divzerof (1);
|
||||
}
|
||||
if (ax > 0xff000000u)
|
||||
return x + x; /* nan */
|
||||
return __math_invalidf (x);
|
||||
}
|
||||
|
||||
float
|
||||
__ieee754_log10f(float x)
|
||||
__ieee754_log10f (float x)
|
||||
{
|
||||
float y,z;
|
||||
int32_t i,k,hx;
|
||||
static const double tr[] =
|
||||
{
|
||||
0x1p+0, 0x1.f81f82p-1, 0x1.f07c1fp-1, 0x1.e9131acp-1,
|
||||
0x1.e1e1e1ep-1, 0x1.dae6077p-1, 0x1.d41d41dp-1, 0x1.cd85689p-1,
|
||||
0x1.c71c71cp-1, 0x1.c0e0704p-1, 0x1.bacf915p-1, 0x1.b4e81b5p-1,
|
||||
0x1.af286bdp-1, 0x1.a98ef6p-1, 0x1.a41a41ap-1, 0x1.9ec8e95p-1,
|
||||
0x1.999999ap-1, 0x1.948b0fdp-1, 0x1.8f9c19p-1, 0x1.8acb90fp-1,
|
||||
0x1.8618618p-1, 0x1.8181818p-1, 0x1.7d05f41p-1, 0x1.78a4c81p-1,
|
||||
0x1.745d174p-1, 0x1.702e05cp-1, 0x1.6c16c17p-1, 0x1.6816817p-1,
|
||||
0x1.642c859p-1, 0x1.605816p-1, 0x1.5c9882cp-1, 0x1.58ed231p-1,
|
||||
0x1.5555555p-1, 0x1.51d07ebp-1, 0x1.4e5e0a7p-1, 0x1.4afd6ap-1,
|
||||
0x1.47ae148p-1, 0x1.446f865p-1, 0x1.4141414p-1, 0x1.3e22cbdp-1,
|
||||
0x1.3b13b14p-1, 0x1.3813814p-1, 0x1.3521cfbp-1, 0x1.323e34ap-1,
|
||||
0x1.2f684bep-1, 0x1.2c9fb4ep-1, 0x1.29e412ap-1, 0x1.27350b9p-1,
|
||||
0x1.2492492p-1, 0x1.21fb781p-1, 0x1.1f7047ep-1, 0x1.1cf06aep-1,
|
||||
0x1.1a7b961p-1, 0x1.1811812p-1, 0x1.15b1e5fp-1, 0x1.135c811p-1,
|
||||
0x1.1111111p-1, 0x1.0ecf56cp-1, 0x1.0c9715p-1, 0x1.0a6810ap-1,
|
||||
0x1.0842108p-1, 0x1.0624dd3p-1, 0x1.041041p-1, 0x1.0204081p-1,
|
||||
0.5
|
||||
};
|
||||
static const double tl[] =
|
||||
{
|
||||
-0x1.d45fd6237ebe3p-47, 0x1.b947689311b6ep-8, 0x1.b5e909c96d7d5p-7,
|
||||
0x1.45f4f59ed2165p-6, 0x1.af5f92cbd8f1ep-6, 0x1.0ba01a606de8cp-5,
|
||||
0x1.3ed119b9a2b7bp-5, 0x1.714834298eec2p-5, 0x1.a30a9d98357fbp-5,
|
||||
0x1.d41d512670813p-5, 0x1.02428c0f65519p-4, 0x1.1a23444eecc3ep-4,
|
||||
0x1.31b30543f4cb4p-4, 0x1.48f3ed39bfd04p-4, 0x1.5fe8049a0e423p-4,
|
||||
0x1.769140a6aa008p-4, 0x1.8cf1836c98cb3p-4, 0x1.a30a9d55541a1p-4,
|
||||
0x1.b8de4d1ee823ep-4, 0x1.ce6e4202ca2e6p-4, 0x1.e3bc1accace07p-4,
|
||||
0x1.f8c9683b5abd4p-4, 0x1.06cbd68ca9a6ep-3, 0x1.11142f19df73p-3,
|
||||
0x1.1b3e71fa7a97fp-3, 0x1.254b4d37a46e3p-3, 0x1.2f3b6912cbf07p-3,
|
||||
0x1.390f683115886p-3, 0x1.42c7e7fffc5a8p-3, 0x1.4c65808c78d3cp-3,
|
||||
0x1.55e8c50751c55p-3, 0x1.5f52445dec3d8p-3, 0x1.68a288c3f12p-3,
|
||||
0x1.71da17bdf0d19p-3, 0x1.7af973608afd9p-3, 0x1.84011952a2579p-3,
|
||||
0x1.8cf1837a7ea6p-3, 0x1.95cb2891e43d6p-3, 0x1.9e8e7b0f869ep-3,
|
||||
0x1.a73beaa5db18dp-3, 0x1.afd3e394558d3p-3, 0x1.b856cf060d9f1p-3,
|
||||
0x1.c0c5134de1ffcp-3, 0x1.c91f1371bc99fp-3, 0x1.d1652ffcd3f53p-3,
|
||||
0x1.d997c6f635e75p-3, 0x1.e1b733ab90f3bp-3, 0x1.e9c3ceadac856p-3,
|
||||
0x1.f1bdeec43a305p-3, 0x1.f9a5e7a5fa3fep-3, 0x1.00be05ac02f2bp-2,
|
||||
0x1.04a054d81a2d4p-2, 0x1.087a0835957fbp-2, 0x1.0c4b457099517p-2,
|
||||
0x1.101431aa1fe51p-2, 0x1.13d4f08b98dd8p-2, 0x1.178da53edb892p-2,
|
||||
0x1.1b3e71e9f9d58p-2, 0x1.1ee777defdeedp-2, 0x1.2288d7b48e23bp-2,
|
||||
0x1.2622b0f52e49fp-2, 0x1.29b522a4c6314p-2, 0x1.2d404b0e30f8p-2,
|
||||
0x1.30c4478f3fbe5p-2, 0x1.34413509f7915p-2
|
||||
};
|
||||
static const union
|
||||
{
|
||||
float f;
|
||||
uint32_t u;
|
||||
} st[] =
|
||||
{
|
||||
{ 0x1p+0 }, { 0x1.4p+3 }, { 0x1.9p+6 }, { 0x1.f4p+9 },
|
||||
{ 0x1.388p+13 }, { 0x1.86ap+16 }, { 0x1.e848p+19 }, { 0x1.312dp+23 },
|
||||
{ 0x1.7d784p+26 }, { 0x1.dcd65p+29 }, { 0x1.2a05f2p+33 }, { 0 },
|
||||
{ 0 }, { 0 }, { 0 }, { 0 }
|
||||
};
|
||||
static const double b[] =
|
||||
{
|
||||
0x1.bcb7b15c5a2f8p-2, -0x1.bcbb1dbb88ebap-3, 0x1.2871c39d521c6p-3
|
||||
};
|
||||
static const double c[] =
|
||||
{
|
||||
0x1.bcb7b1526e50ep-2, -0x1.bcb7b1526e53dp-3, 0x1.287a7636f3fa2p-3,
|
||||
-0x1.bcb7b146a14b3p-4, 0x1.63c627d5219cbp-4, -0x1.2880736c8762dp-4,
|
||||
0x1.fc1ecf913961ap-5
|
||||
};
|
||||
uint32_t ux = asuint (x);
|
||||
if (__glibc_unlikely (ux < (1 << 23) || ux >= 0x7f800000u))
|
||||
{
|
||||
if (ux == 0 || ux >= 0x7f800000u)
|
||||
return as_special (x);
|
||||
/* subnormal */
|
||||
int n = __builtin_clz (ux) - 8;
|
||||
ux <<= n;
|
||||
ux -= n << 23;
|
||||
}
|
||||
unsigned m = ux & ((1 << 23) - 1), j = (m + (1 << (23 - 7))) >> (23 - 6);
|
||||
double ix = tr[j], l = tl[j];
|
||||
int e = ((int) ux >> 23) - 127;
|
||||
unsigned je = e + 1;
|
||||
je = (je * 0x4d104d4) >> 28;
|
||||
if (__glibc_unlikely (ux == st[je].u))
|
||||
return je;
|
||||
|
||||
GET_FLOAT_WORD(hx,x);
|
||||
|
||||
k=0;
|
||||
if (hx < 0x00800000) { /* x < 2**-126 */
|
||||
if (__builtin_expect((hx&0x7fffffff)==0, 0))
|
||||
return -two25/fabsf (x); /* log(+-0)=-inf */
|
||||
if (__builtin_expect(hx<0, 0))
|
||||
return (x-x)/(x-x); /* log(-#) = NaN */
|
||||
k -= 25; x *= two25; /* subnormal number, scale up x */
|
||||
GET_FLOAT_WORD(hx,x);
|
||||
double tz = asdouble (((int64_t) m | ((int64_t) 1023 << 23)) << (52 - 23));
|
||||
double z = tz * ix - 1, z2 = z * z;
|
||||
double r
|
||||
= ((e * 0x1.34413509f79ffp-2 + l) + z * b[0]) + z2 * (b[1] + z * b[2]);
|
||||
float ub = r, lb = r + 0x1.b008p-34;
|
||||
if (__glibc_unlikely (ub != lb))
|
||||
{
|
||||
double f = z
|
||||
* ((c[0] + z * c[1])
|
||||
+ z2
|
||||
* ((c[2] + z * c[3])
|
||||
+ z2 * (c[4] + z * c[5] + z2 * c[6])));
|
||||
f -= 0x1.0cee0ed4ca7e9p-54 * e;
|
||||
f += l - tl[0];
|
||||
double el = e * 0x1.34413509f7ap-2;
|
||||
r = el + f;
|
||||
ub = r;
|
||||
tz = r;
|
||||
if (__glibc_unlikely (!((asuint64 (tz) & ((1 << 28) - 1)))))
|
||||
{
|
||||
double dr = (el - r) + f;
|
||||
r += dr * 32;
|
||||
ub = r;
|
||||
}
|
||||
if (__builtin_expect(hx >= 0x7f800000, 0)) return x+x;
|
||||
k += (hx>>23)-127;
|
||||
i = ((uint32_t)k&0x80000000)>>31;
|
||||
hx = (hx&0x007fffff)|((0x7f-i)<<23);
|
||||
y = (float)(k+i);
|
||||
if (FIX_INT_FP_CONVERT_ZERO && y == 0.0f)
|
||||
y = 0.0f;
|
||||
SET_FLOAT_WORD(x,hx);
|
||||
z = y*log10_2lo + ivln10*__ieee754_logf(x);
|
||||
return z+y*log10_2hi;
|
||||
}
|
||||
return ub;
|
||||
}
|
||||
libm_alias_finite (__ieee754_log10f, __log10f)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user