glibc/sysdeps/ieee754/flt-32/s_sincosf.c
Adhemerval Zanella 5a6f2cabb6 i686: Use generic sincosf implementation for SSE2 version
The generic implementation shows slight better performance
(gcc 11.2.1 on a Ryzen 9 5900X):

* s_sincosf-sse2.S:
  "sincosf": {
   "workload-random": {
    "duration": 3.89961e+09,
    "iterations": 9.5472e+07,
    "reciprocal-throughput": 40.8429,
    "latency": 40.8483,
    "max-throughput": 2.4484e+07,
    "min-throughput": 2.44808e+07
   }
  }

* generic s_cossinf.c:
  "sincosf": {
   "workload-random": {
    "duration": 3.71953e+09,
    "iterations": 1.48512e+08,
    "reciprocal-throughput": 25.0515,
    "latency": 25.0391,
    "max-throughput": 3.99177e+07,
    "min-throughput": 3.99375e+07
   }
  }

Checked on i686-linux-gnu.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2022-06-01 10:47:44 -03:00

109 lines
2.9 KiB
C

/* Compute sine and cosine of argument.
Copyright (C) 2018-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <stdint.h>
#include <math.h>
#include <math-barriers.h>
#include <libm-alias-float.h>
#include "math_config.h"
#include "s_sincosf.h"
#ifndef SECTION
# define SECTION
#endif
#ifndef SINCOSF
# define SINCOSF_FUNC __sincosf
#else
# define SINCOSF_FUNC SINCOSF
#endif
/* Fast sincosf implementation. Worst-case ULP is 0.5607, maximum relative
error is 0.5303 * 2^-23. A single-step range reduction is used for
small values. Large inputs have their range reduced using fast integer
arithmetic. */
void
SECTION
SINCOSF_FUNC (float y, float *sinp, float *cosp)
{
double x = y;
double s;
int n;
const sincos_t *p = &__sincosf_table[0];
if (abstop12 (y) < abstop12 (pio4))
{
double x2 = x * x;
if (__glibc_unlikely (abstop12 (y) < abstop12 (0x1p-12f)))
{
/* Force underflow for tiny y. */
if (__glibc_unlikely (abstop12 (y) < abstop12 (0x1p-126f)))
math_force_eval ((float)x2);
*sinp = y;
*cosp = 1.0f;
return;
}
sincosf_poly (x, x2, p, 0, sinp, cosp);
}
else if (abstop12 (y) < abstop12 (120.0f))
{
x = reduce_fast (x, p, &n);
/* Setup the signs for sin and cos. */
s = p->sign[n & 3];
if (n & 2)
p = &__sincosf_table[1];
sincosf_poly (x * s, x * x, p, n, sinp, cosp);
}
else if (__glibc_likely (abstop12 (y) < abstop12 (INFINITY)))
{
uint32_t xi = asuint (y);
int sign = xi >> 31;
x = reduce_large (xi, &n);
/* Setup signs for sin and cos - include original sign. */
s = p->sign[(n + sign) & 3];
if ((n + sign) & 2)
p = &__sincosf_table[1];
sincosf_poly (x * s, x * x, p, n, sinp, cosp);
}
else
{
/* Return NaN if Inf or NaN for both sin and cos. */
*sinp = *cosp = y - y;
#if WANT_ERRNO
/* Needed to set errno for +-Inf, the add is a hack to work
around a gcc register allocation issue: just passing y
affects code generation in the fast path (PR86901). */
__math_invalidf (y + y);
#endif
}
}
#ifndef SINCOSF
libm_alias_float (__sincos, sincos)
#endif