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Use generic sinf/cosf in lgammaf_r

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The internal functions __kernel_sinf and __kernel_cosf are used only by
lgammaf_r.  Removing the internal functions and using the generic sinf
and cosf is better overall.  Benchmarking on Cortex-A72 shows the generic
sinf and cosf are 1.4x and 2.3x faster in the range |x| < PI/4, and 0.66x
and 1.1x for |x| < PI/2, so it should make lgammaf_r faster on average.

GLIBC regression tests pass on AArch64.

	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (sin_pif): Use __sinf/__cosf.
	* sysdeps/ieee754/flt-32/k_cosf.c (__kernel_cosf): Remove all code.
	* sysdeps/ieee754/flt-32/k_sinf.c (__kernel_sinf): Likewise.
This commit is contained in:
Wilco Dijkstra 2018-08-15 16:01:21 +01:00
parent 49acec179c
commit 126c4e3f80
4 changed files with 14 additions and 112 deletions
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6
ChangeLog
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@ -1,3 +1,9 @@
2018-08-15 Wilco Dijkstra <wdijkstr@arm.com>
* sysdeps/ieee754/flt-32/e_lgammaf_r.c (sin_pif): Use __sinf/__cosf.
* sysdeps/ieee754/flt-32/k_cosf.c (__kernel_cosf): Remove all code.
* sysdeps/ieee754/flt-32/k_sinf.c (__kernel_sinf): Likewise.
2018-08-15 Wilco Dijkstra <wdijkstr@arm.com>
* sysdeps/x86_64/fpu/libm-test-ulps: Regenerate to fix spaces.

12
sysdeps/ieee754/flt-32/e_lgammaf_r.c
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@ -97,7 +97,7 @@ sin_pif(float x)
GET_FLOAT_WORD(ix,x);
ix &= 0x7fffffff;
if(ix<0x3e800000) return __kernel_sinf(pi*x,zero,0);
if(ix<0x3e800000) return __sinf (pi*x);
y = -x; /* x is assume negative */
/*
@ -121,14 +121,14 @@ sin_pif(float x)
}
}
switch (n) {
case 0: y = __kernel_sinf(pi*y,zero,0); break;
case 0: y = __sinf (pi*y); break;
case 1:
case 2: y = __kernel_cosf(pi*((float)0.5-y),zero); break;
case 2: y = __cosf (pi*((float)0.5-y)); break;
case 3:
case 4: y = __kernel_sinf(pi*(one-y),zero,0); break;
case 4: y = __sinf (pi*(one-y)); break;
case 5:
case 6: y = -__kernel_cosf(pi*(y-(float)1.5),zero); break;
default: y = __kernel_sinf(pi*(y-(float)2.0),zero,0); break;
case 6: y = -__cosf (pi*(y-(float)1.5)); break;
default: y = __sinf (pi*(y-(float)2.0)); break;
}
return -y;
}

56
sysdeps/ieee754/flt-32/k_cosf.c
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@ -1,55 +1 @@
/* k_cosf.c -- float version of k_cos.c
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* 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.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: k_cosf.c,v 1.4 1995/05/10 20:46:23 jtc Exp $";
#endif
#include <math.h>
#include <math_private.h>
static const float
one = 1.0000000000e+00, /* 0x3f800000 */
C1 = 4.1666667908e-02, /* 0x3d2aaaab */
C2 = -1.3888889225e-03, /* 0xbab60b61 */
C3 = 2.4801587642e-05, /* 0x37d00d01 */
C4 = -2.7557314297e-07, /* 0xb493f27c */
C5 = 2.0875723372e-09, /* 0x310f74f6 */
C6 = -1.1359647598e-11; /* 0xad47d74e */
float __kernel_cosf(float x, float y)
{
float a,hz,z,r,qx;
int32_t ix;
GET_FLOAT_WORD(ix,x);
ix &= 0x7fffffff; /* ix = |x|'s high word*/
if(ix<0x32000000) { /* if x < 2**27 */
if(((int)x)==0) return one; /* generate inexact */
}
z = x*x;
r = z*(C1+z*(C2+z*(C3+z*(C4+z*(C5+z*C6)))));
if(ix < 0x3e99999a) /* if |x| < 0.3 */
return one - ((float)0.5*z - (z*r - x*y));
else {
if(ix > 0x3f480000) { /* x > 0.78125 */
qx = (float)0.28125;
} else {
SET_FLOAT_WORD(qx,ix-0x01000000); /* x/4 */
}
hz = (float)0.5*z-qx;
a = one-qx;
return a - (hz - (z*r-x*y));
}
}
/* Not needed. */

52
sysdeps/ieee754/flt-32/k_sinf.c
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@ -1,51 +1 @@
/* k_sinf.c -- float version of k_sin.c
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* 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.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: k_sinf.c,v 1.4 1995/05/10 20:46:33 jtc Exp $";
#endif
#include <float.h>
#include <math.h>
#include <math_private.h>
#include <math-underflow.h>
static const float
half = 5.0000000000e-01,/* 0x3f000000 */
S1 = -1.6666667163e-01, /* 0xbe2aaaab */
S2 = 8.3333337680e-03, /* 0x3c088889 */
S3 = -1.9841270114e-04, /* 0xb9500d01 */
S4 = 2.7557314297e-06, /* 0x3638ef1b */
S5 = -2.5050759689e-08, /* 0xb2d72f34 */
S6 = 1.5896910177e-10; /* 0x2f2ec9d3 */
float __kernel_sinf(float x, float y, int iy)
{
float z,r,v;
int32_t ix;
GET_FLOAT_WORD(ix,x);
ix &= 0x7fffffff; /* high word of x */
if(ix<0x32000000) /* |x| < 2**-27 */
{
math_check_force_underflow (x);
if ((int) x == 0)
return x; /* generate inexact */
}
z = x*x;
v = z*x;
r = S2+z*(S3+z*(S4+z*(S5+z*S6)));
if(iy==0) return x+v*(S1+z*r);
else return x-((z*(half*y-v*r)-y)-v*S1);
}
/* Not needed. */