glibc/sysdeps/libm-ieee754/e_powf.c
Ulrich Drepper 6bc31da01b update from main archive 970101
Wed Jan  1 15:15:00 1997  Ulrich Drepper  <drepper@cygnus.com>

	* libio/Makefile (routines): Add fcloseall.
	* libio/fcloseall.c: New file.
	* libio/stdio.h [__USE_GNU]: Add prototype for fcloseall.
	* libio/iofclose.c: Don't close all streams when argument is NULL.

	* stdio/Makefile (routines): Add fcloseall.
	* stdio/fcloseall.c: New file.
	* stdio/stdio.h [__USE_GNU]: Add prototype for fcloseall.
	* stdio/fclose.c: Don't close all streams when argument is NULL.

	* manual/stdio.texi: Document fcloseall.

	* sysdeps/generic/abort.c: Call __fcloseall instead of fclose with
	NULL argument.

	* socket/sys/un.h (SUN_LEN): Add cast.

	* sunrpc/auth_unix.c (authunix_create): Change parameter types
	of uid, gid, and aup_gids to uid_t and gid_t respectively.
	(authunix_create_default): Likewise.
	(authunix_refresh): Correct cast for aup_gids assignment.
	* sunrpc/rpc/auth.h (authunix_create): Correct types in declaration.
	* sunrpc/rpc/auth_unix.h (struct authunix_parms): Correct field
	types to uid_t and gid_t respectively.
	(struct short_hand_verf): Likewise.
	Reported by Andreas Schwab.

	* sysdeps/ieee754/Makefile: New file.  Make sure ieee754.h gets
	installed.
	* sysdeps/ieee754/ieee754.h: Protect against multiple inclusion and
	use in C++ programs.

	* sysdeps/libm-i387/e_pow.S: New file.  Optimized ix87 assembler
	version of pow() function.
	* sysdeps/libm-i387/e_powf.S: New file.  Float version.
	* sysdeps/libm-i387/e_powl.S: New file.  Long double version.

	* sysdeps/libm-i387/s_expm1.S: New file.  Optimized ix87 assembler
	version of expm1() function.
	* sysdeps/libm-i387/s_expm1f.S: New file.  Float version.
	* sysdeps/libm-i387/s_expm1l.S: New file.  Long double version.

	* sysdeps/libm-i387/e_exp.S: Optimize handling of +-Inf.
	Better handling of computation stack from current NetBSD sources.
	* sysdeps/libm-i387/e_expf.S: Likewise.
	* sysdeps/libm-i387/e_expl.S: Likewise.

	* sysdeps/libm-i387/e_log.S: Use fstp instead of fincstp.
	* sysdeps/libm-i387/e_logf.S: Likewise.
	* sysdeps/libm-i387/e_logl.S: Likewise.
	* sysdeps/libm-i387/e_log10.S: Likewise.
	* sysdeps/libm-i387/e_log10f.S: Likewise.
	* sysdeps/libm-i387/e_log10l.S: Likewise.
	* sysdeps/libm-i387/s_asinh.S: Likewise.
	* sysdeps/libm-i387/s_asinhf.S: Likewise.
	* sysdeps/libm-i387/s_asinhl.S: Likewise.
	* sysdeps/libm-i387/s_significandl.S: Likewise.

	* sysdeps/libm-i387/s_ceil.S: Don't create stack frame.  Modify
	stack pointer directly.  Use 32 bit instead of 16 bit operations.
	* sysdeps/libm-i387/s_ceilf.S: Likewise.
	* sysdeps/libm-i387/s_ceill.S: Likewise.
	* sysdeps/libm-i387/s_floor.S: Likewise.
	* sysdeps/libm-i387/s_floorf.S: Likewise.
	* sysdeps/libm-i387/s_floorl.S: Likewise.

	* sysdeps/libm-ieee754/e_coshf.c (huge): Don't declare volatile.
	* sysdeps/libm-ieee754/e_expf.c: Likewise.
	* sysdeps/libm-ieee754/e_powf.c: Likewise.
	From current NetBSD sources.

	* sysdeps/libm-ieee754/e_hypot.c (__ieee754_hypot): Don't initialize
	`a' and `b' in definition.
	* sysdeps/libm-ieee754/e_hypotf.c: Likewise.

	* sysdeps/libm-ieee754/e_hypotl.c: New file.  Long double
	implementation.
	* sysdeps/libm-ieee754/e_sinhl.c: New file.  Long double
	implementation.
	* sysdeps/stub/e_hypotl.c: Removed.  We have a real version now.
	* sysdeps/stub/e_sinhl.c: Removed.

	* sysdeps/posix/sigpause.c (__sigpause): Use sigdelset instead of
	sigaddset.  Reported by Andreas Schwab.
	(__default_sigpause): New function.  Call __sigpause as BSD version.
	Make this the default function by providing alias sigpause.
	* sysdeps/stub/sigpause.c (__default_sigpause): New funciton.
	Simply fail.  Provide alias sigpause.

Wed Jan  1 12:34:54 1997  Ulrich Drepper  <drepper@cygnus.com>

	* po/es.po: Update for glibc-1.98.
	* po/fr.po: Likewise.
	* po/sv.po: New file.  Swedish translation.

Wed Jan  1 12:18:07 1997   MacGyver  <macgyver@tos.net>

	* values.h: Fix typos: use SHRT_MAX but SHORT_MAX and SHRT_MIN but
	SHORT_MIN.

Tue Dec 24 23:10:21 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* Makefile: Replace `stubs.h' by `gnu/stubs.h'.
	* features.h: Include <gnu/stubs.h> instead of <stubs.h>.

Tue Dec 24 22:16:55 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* Makefile (subdirs): Move `elf' last so that librtld.so isn't
	relinked in the `make others' pass if an add-on adds something to
	libc.

Mon Dec 23 21:23:16 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/m68k/abort-instr.h: New File.

Mon Dec 23 21:16:38 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/m68k/Makefile ($(subdir)=elf): Define CFLAGS-rtld.c
	to prevent warning.

Mon Dec 23 21:14:22 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* resolv/Makefile (subdirs-dirs): Define.

Mon Dec 23 20:56:49 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/gnu/utmpbits.h (struct utmp): Fix padding.

Mon Dec 30 11:05:11 1996  Ulrich Drepper  <drepper@cygnus.com>

	Update from ADO tzcode1996o.
	* time/difftime.c: De-ANSI-declfy.  Simplify computation of hibit
	according to ADO version.
	* time/zic.c: Correct typo is message.

	Update from ADO tzdata1996n.
	* time/asia: Updated.
	* time/australasia: Likewise.
	* time/europe: Likewise.
	* time/northamerica: Likewise.
	* time/southamerica: Likewise.
1997-01-01 15:28:18 +00:00

254 lines
7.4 KiB
C

/* e_powf.c -- float version of e_pow.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: e_powf.c,v 1.7 1996/04/08 15:43:44 phil Exp $";
#endif
#include "math.h"
#include "math_private.h"
static const float huge = 1.0e+30, tiny = 1.0e-30;
#ifdef __STDC__
static const float
#else
static float
#endif
bp[] = {1.0, 1.5,},
dp_h[] = { 0.0, 5.84960938e-01,}, /* 0x3f15c000 */
dp_l[] = { 0.0, 1.56322085e-06,}, /* 0x35d1cfdc */
zero = 0.0,
one = 1.0,
two = 2.0,
two24 = 16777216.0, /* 0x4b800000 */
/* poly coefs for (3/2)*(log(x)-2s-2/3*s**3 */
L1 = 6.0000002384e-01, /* 0x3f19999a */
L2 = 4.2857143283e-01, /* 0x3edb6db7 */
L3 = 3.3333334327e-01, /* 0x3eaaaaab */
L4 = 2.7272811532e-01, /* 0x3e8ba305 */
L5 = 2.3066075146e-01, /* 0x3e6c3255 */
L6 = 2.0697501302e-01, /* 0x3e53f142 */
P1 = 1.6666667163e-01, /* 0x3e2aaaab */
P2 = -2.7777778450e-03, /* 0xbb360b61 */
P3 = 6.6137559770e-05, /* 0x388ab355 */
P4 = -1.6533901999e-06, /* 0xb5ddea0e */
P5 = 4.1381369442e-08, /* 0x3331bb4c */
lg2 = 6.9314718246e-01, /* 0x3f317218 */
lg2_h = 6.93145752e-01, /* 0x3f317200 */
lg2_l = 1.42860654e-06, /* 0x35bfbe8c */
ovt = 4.2995665694e-08, /* -(128-log2(ovfl+.5ulp)) */
cp = 9.6179670095e-01, /* 0x3f76384f =2/(3ln2) */
cp_h = 9.6179199219e-01, /* 0x3f763800 =head of cp */
cp_l = 4.7017383622e-06, /* 0x369dc3a0 =tail of cp_h */
ivln2 = 1.4426950216e+00, /* 0x3fb8aa3b =1/ln2 */
ivln2_h = 1.4426879883e+00, /* 0x3fb8aa00 =16b 1/ln2*/
ivln2_l = 7.0526075433e-06; /* 0x36eca570 =1/ln2 tail*/
#ifdef __STDC__
float __ieee754_powf(float x, float y)
#else
float __ieee754_powf(x,y)
float x, y;
#endif
{
float z,ax,z_h,z_l,p_h,p_l;
float y1,t1,t2,r,s,t,u,v,w;
int32_t i,j,k,yisint,n;
int32_t hx,hy,ix,iy,is;
GET_FLOAT_WORD(hx,x);
GET_FLOAT_WORD(hy,y);
ix = hx&0x7fffffff; iy = hy&0x7fffffff;
/* y==zero: x**0 = 1 */
if(iy==0) return one;
/* +-NaN return x+y */
if(ix > 0x7f800000 ||
iy > 0x7f800000)
return x+y;
/* determine if y is an odd int when x < 0
* yisint = 0 ... y is not an integer
* yisint = 1 ... y is an odd int
* yisint = 2 ... y is an even int
*/
yisint = 0;
if(hx<0) {
if(iy>=0x4b800000) yisint = 2; /* even integer y */
else if(iy>=0x3f800000) {
k = (iy>>23)-0x7f; /* exponent */
j = iy>>(23-k);
if((j<<(23-k))==iy) yisint = 2-(j&1);
}
}
/* special value of y */
if (iy==0x7f800000) { /* y is +-inf */
if (ix==0x3f800000)
return y - y; /* inf**+-1 is NaN */
else if (ix > 0x3f800000)/* (|x|>1)**+-inf = inf,0 */
return (hy>=0)? y: zero;
else /* (|x|<1)**-,+inf = inf,0 */
return (hy<0)?-y: zero;
}
if(iy==0x3f800000) { /* y is +-1 */
if(hy<0) return one/x; else return x;
}
if(hy==0x40000000) return x*x; /* y is 2 */
if(hy==0x3f000000) { /* y is 0.5 */
if(hx>=0) /* x >= +0 */
return __ieee754_sqrtf(x);
}
ax = fabsf(x);
/* special value of x */
if(ix==0x7f800000||ix==0||ix==0x3f800000){
z = ax; /*x is +-0,+-inf,+-1*/
if(hy<0) z = one/z; /* z = (1/|x|) */
if(hx<0) {
if(((ix-0x3f800000)|yisint)==0) {
z = (z-z)/(z-z); /* (-1)**non-int is NaN */
} else if(yisint==1)
z = -z; /* (x<0)**odd = -(|x|**odd) */
}
return z;
}
/* (x<0)**(non-int) is NaN */
if(((((u_int32_t)hx>>31)-1)|yisint)==0) return (x-x)/(x-x);
/* |y| is huge */
if(iy>0x4d000000) { /* if |y| > 2**27 */
/* over/underflow if x is not close to one */
if(ix<0x3f7ffff8) return (hy<0)? huge*huge:tiny*tiny;
if(ix>0x3f800007) return (hy>0)? huge*huge:tiny*tiny;
/* now |1-x| is tiny <= 2**-20, suffice to compute
log(x) by x-x^2/2+x^3/3-x^4/4 */
t = x-1; /* t has 20 trailing zeros */
w = (t*t)*((float)0.5-t*((float)0.333333333333-t*(float)0.25));
u = ivln2_h*t; /* ivln2_h has 16 sig. bits */
v = t*ivln2_l-w*ivln2;
t1 = u+v;
GET_FLOAT_WORD(is,t1);
SET_FLOAT_WORD(t1,is&0xfffff000);
t2 = v-(t1-u);
} else {
float s2,s_h,s_l,t_h,t_l;
n = 0;
/* take care subnormal number */
if(ix<0x00800000)
{ax *= two24; n -= 24; GET_FLOAT_WORD(ix,ax); }
n += ((ix)>>23)-0x7f;
j = ix&0x007fffff;
/* determine interval */
ix = j|0x3f800000; /* normalize ix */
if(j<=0x1cc471) k=0; /* |x|<sqrt(3/2) */
else if(j<0x5db3d7) k=1; /* |x|<sqrt(3) */
else {k=0;n+=1;ix -= 0x00800000;}
SET_FLOAT_WORD(ax,ix);
/* compute s = s_h+s_l = (x-1)/(x+1) or (x-1.5)/(x+1.5) */
u = ax-bp[k]; /* bp[0]=1.0, bp[1]=1.5 */
v = one/(ax+bp[k]);
s = u*v;
s_h = s;
GET_FLOAT_WORD(is,s_h);
SET_FLOAT_WORD(s_h,is&0xfffff000);
/* t_h=ax+bp[k] High */
SET_FLOAT_WORD(t_h,((ix>>1)|0x20000000)+0x0040000+(k<<21));
t_l = ax - (t_h-bp[k]);
s_l = v*((u-s_h*t_h)-s_h*t_l);
/* compute log(ax) */
s2 = s*s;
r = s2*s2*(L1+s2*(L2+s2*(L3+s2*(L4+s2*(L5+s2*L6)))));
r += s_l*(s_h+s);
s2 = s_h*s_h;
t_h = (float)3.0+s2+r;
GET_FLOAT_WORD(is,t_h);
SET_FLOAT_WORD(t_h,is&0xfffff000);
t_l = r-((t_h-(float)3.0)-s2);
/* u+v = s*(1+...) */
u = s_h*t_h;
v = s_l*t_h+t_l*s;
/* 2/(3log2)*(s+...) */
p_h = u+v;
GET_FLOAT_WORD(is,p_h);
SET_FLOAT_WORD(p_h,is&0xfffff000);
p_l = v-(p_h-u);
z_h = cp_h*p_h; /* cp_h+cp_l = 2/(3*log2) */
z_l = cp_l*p_h+p_l*cp+dp_l[k];
/* log2(ax) = (s+..)*2/(3*log2) = n + dp_h + z_h + z_l */
t = (float)n;
t1 = (((z_h+z_l)+dp_h[k])+t);
GET_FLOAT_WORD(is,t1);
SET_FLOAT_WORD(t1,is&0xfffff000);
t2 = z_l-(((t1-t)-dp_h[k])-z_h);
}
s = one; /* s (sign of result -ve**odd) = -1 else = 1 */
if(((((u_int32_t)hx>>31)-1)|(yisint-1))==0)
s = -one; /* (-ve)**(odd int) */
/* split up y into y1+y2 and compute (y1+y2)*(t1+t2) */
GET_FLOAT_WORD(is,y);
SET_FLOAT_WORD(y1,is&0xfffff000);
p_l = (y-y1)*t1+y*t2;
p_h = y1*t1;
z = p_l+p_h;
GET_FLOAT_WORD(j,z);
if (j>0x43000000) /* if z > 128 */
return s*huge*huge; /* overflow */
else if (j==0x43000000) { /* if z == 128 */
if(p_l+ovt>z-p_h) return s*huge*huge; /* overflow */
}
else if ((j&0x7fffffff)>0x43160000) /* z <= -150 */
return s*tiny*tiny; /* underflow */
else if ((u_int32_t) j==0xc3160000){ /* z == -150 */
if(p_l<=z-p_h) return s*tiny*tiny; /* underflow */
}
/*
* compute 2**(p_h+p_l)
*/
i = j&0x7fffffff;
k = (i>>23)-0x7f;
n = 0;
if(i>0x3f000000) { /* if |z| > 0.5, set n = [z+0.5] */
n = j+(0x00800000>>(k+1));
k = ((n&0x7fffffff)>>23)-0x7f; /* new k for n */
SET_FLOAT_WORD(t,n&~(0x007fffff>>k));
n = ((n&0x007fffff)|0x00800000)>>(23-k);
if(j<0) n = -n;
p_h -= t;
}
t = p_l+p_h;
GET_FLOAT_WORD(is,t);
SET_FLOAT_WORD(t,is&0xfffff000);
u = t*lg2_h;
v = (p_l-(t-p_h))*lg2+t*lg2_l;
z = u+v;
w = v-(z-u);
t = z*z;
t1 = z - t*(P1+t*(P2+t*(P3+t*(P4+t*P5))));
r = (z*t1)/(t1-two)-(w+z*w);
z = one-(r-z);
GET_FLOAT_WORD(j,z);
j += (n<<23);
if((j>>23)<=0) z = __scalbnf(z,n); /* subnormal output */
else SET_FLOAT_WORD(z,j);
return s*z;
}