glibc/sysdeps/x86/fpu/sincosf_poly.h

112 lines
3.1 KiB
C

/* Used by sinf, cosf and sincosf functions. X86-64 version.
Copyright (C) 2018-2023 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/>. */
typedef double v2df_t __attribute__ ((vector_size (2 * sizeof (double))));
#ifdef __SSE2_MATH__
typedef float v4sf_t __attribute__ ((vector_size (4 * sizeof (float))));
static inline void
v2df_to_sf (v2df_t v2df, float *f0p, float *f1p)
{
v4sf_t v4sf = __builtin_ia32_cvtpd2ps (v2df);
*f0p = v4sf[0];
*f1p = v4sf[1];
}
#else
static inline void
v2df_to_sf (v2df_t v2df, float *f0p, float *f1p)
{
*f0p = (float) v2df[0];
*f1p = (float) v2df[1];
}
#endif
/* The constants and polynomials for sine and cosine. */
typedef struct
{
double sign[4]; /* Sign of sine in quadrants 0..3. */
double hpi_inv; /* 2 / PI ( * 2^24 if !TOINT_INTRINSICS). */
double hpi; /* PI / 2. */
/* Cosine polynomial: c0, c1, c2, c3, c4.
Sine polynomial: s1, s2, s3. */
double c0, c1;
v2df_t s1c2, s2c3, s3c4;
} sincos_t;
/* Compute the sine and cosine of inputs X and X2 (X squared), using the
polynomial P and store the results in SINP and COSP. N is the quadrant,
if odd the cosine and sine polynomials are swapped. */
static inline void
sincosf_poly (double x, double x2, const sincos_t *p, int n, float *sinp,
float *cosp)
{
v2df_t vx2x2 = { x2, x2 };
v2df_t vxx2 = { x, x2 };
v2df_t vx3x4, vs1c2;
vx3x4 = vx2x2 * vxx2;
vs1c2 = p->s2c3 + vx2x2 * p->s3c4;
/* Swap sin/cos result based on quadrant. */
if (n & 1)
{
float *tmp = cosp;
cosp = sinp;
sinp = tmp;
}
double c1 = p->c0 + x2 * p->c1;
v2df_t vxc1 = { x, c1 };
v2df_t vx5x6 = vx3x4 * vx2x2;
v2df_t vsincos = vxc1 + vx3x4 * p->s1c2;
vsincos = vsincos + vx5x6 * vs1c2;
v2df_to_sf (vsincos, sinp, cosp);
}
/* Return the sine of inputs X and X2 (X squared) using the polynomial P.
N is the quadrant, and if odd the cosine polynomial is used. */
static inline float
sinf_poly (double x, double x2, const sincos_t *p, int n)
{
double x3, x4, x6, x7, s, c, c1, c2, s1;
if ((n & 1) == 0)
{
x3 = x * x2;
s1 = p->s2c3[0] + x2 * p->s3c4[0];
x7 = x3 * x2;
s = x + x3 * p->s1c2[0];
return s + x7 * s1;
}
else
{
x4 = x2 * x2;
c2 = p->s2c3[1] + x2 * p->s3c4[1];
c1 = p->c0 + x2 * p->c1;
x6 = x4 * x2;
c = c1 + x4 * p->s1c2[1];
return c + x6 * c2;
}
}