Module Name: src
Committed By: christos
Date: Sat Aug 27 10:01:08 UTC 2016
Modified Files:
src/lib/libm/src: e_pow.c e_powf.c
Log Message:
sync with FreeBSD
To generate a diff of this commit:
cvs rdiff -u -r1.16 -r1.17 src/lib/libm/src/e_pow.c
cvs rdiff -u -r1.15 -r1.16 src/lib/libm/src/e_powf.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/libm/src/e_pow.c
diff -u src/lib/libm/src/e_pow.c:1.16 src/lib/libm/src/e_pow.c:1.17
--- src/lib/libm/src/e_pow.c:1.16 Fri Apr 23 15:17:07 2010
+++ src/lib/libm/src/e_pow.c Sat Aug 27 06:01:08 2016
@@ -1,9 +1,8 @@
-/* @(#)e_pow.c 5.1 93/09/24 */
+/* @(#)e_pow.c 1.5 04/04/22 SMI */
/*
* ====================================================
- * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ * Copyright (C) 2004 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.
@@ -12,7 +11,7 @@
#include <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
-__RCSID("$NetBSD: e_pow.c,v 1.16 2010/04/23 19:17:07 drochner Exp $");
+__RCSID("$NetBSD: e_pow.c,v 1.17 2016/08/27 10:01:08 christos Exp $");
#endif
/* __ieee754_pow(x,y) return x**y
@@ -29,13 +28,13 @@ __RCSID("$NetBSD: e_pow.c,v 1.16 2010/04
* Special cases:
* 1. (anything) ** 0 is 1
* 2. (anything) ** 1 is itself
- * 3. (anything) ** NAN is NAN
+ * 3. (anything) ** NAN is NAN except 1 ** NAN = 1
* 4. NAN ** (anything except 0) is NAN
* 5. +-(|x| > 1) ** +INF is +INF
* 6. +-(|x| > 1) ** -INF is +0
* 7. +-(|x| < 1) ** +INF is +0
* 8. +-(|x| < 1) ** -INF is +INF
- * 9. +-1 ** +-INF is NAN
+ * 9. +-1 ** +-INF is 1
* 10. +0 ** (+anything except 0, NAN) is +0
* 11. -0 ** (+anything except 0, NAN, odd integer) is +0
* 12. +0 ** (-anything except 0, NAN) is +INF
@@ -113,10 +112,13 @@ __ieee754_pow(double x, double y)
/* y==zero: x**0 = 1 */
if((iy|ly)==0) return one;
- /* +-NaN return x+y */
+ /* x==1: 1**y = 1, even if y is NaN */
+ if (hx==0x3ff00000 && lx == 0) return one;
+
+ /* y!=zero: result is NaN if either arg is NaN */
if(ix > 0x7ff00000 || ((ix==0x7ff00000)&&(lx!=0)) ||
iy > 0x7ff00000 || ((iy==0x7ff00000)&&(ly!=0)))
- return x+y;
+ return (x+0.0)+(y+0.0);
/* determine if y is an odd int when x < 0
* yisint = 0 ... y is not an integer
@@ -142,7 +144,7 @@ __ieee754_pow(double x, double y)
if(ly==0) {
if (iy==0x7ff00000) { /* y is +-inf */
if(((ix-0x3ff00000)|lx)==0)
- return y - y; /* inf**+-1 is NaN */
+ return one; /* (-1)**+-inf is 1 */
else if (ix >= 0x3ff00000)/* (|x|>1)**+-inf = inf,0 */
return (hy>=0)? y: zero;
else /* (|x|<1)**-,+inf = inf,0 */
@@ -174,7 +176,11 @@ __ieee754_pow(double x, double y)
}
}
+ /* CYGNUS LOCAL + fdlibm-5.3 fix: This used to be
n = (hx>>31)+1;
+ but ANSI C says a right shift of a signed negative quantity is
+ implementation defined. */
+ n = ((u_int32_t)hx>>31)-1;
/* (x<0)**(non-int) is NaN */
if((n|yisint)==0) return (x-x)/(x-x);
Index: src/lib/libm/src/e_powf.c
diff -u src/lib/libm/src/e_powf.c:1.15 src/lib/libm/src/e_powf.c:1.16
--- src/lib/libm/src/e_powf.c:1.15 Fri Apr 23 15:17:07 2010
+++ src/lib/libm/src/e_powf.c Sat Aug 27 06:01:08 2016
@@ -15,15 +15,13 @@
#include <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
-__RCSID("$NetBSD: e_powf.c,v 1.15 2010/04/23 19:17:07 drochner Exp $");
+__RCSID("$NetBSD: e_powf.c,v 1.16 2016/08/27 10:01:08 christos Exp $");
#endif
#include "namespace.h"
#include "math.h"
#include "math_private.h"
-static const float huge = 1.0e+30, tiny = 1.0e-30;
-
static const float
bp[] = {1.0, 1.5,},
dp_h[] = { 0.0, 5.84960938e-01,}, /* 0x3f15c000 */
@@ -32,6 +30,8 @@ zero = 0.0,
one = 1.0,
two = 2.0,
two24 = 16777216.0, /* 0x4b800000 */
+huge = 1.0e30,
+tiny = 1.0e-30,
/* poly coefs for (3/2)*(log(x)-2s-2/3*s**3 */
L1 = 6.0000002384e-01, /* 0x3f19999a */
L2 = 4.2857143283e-01, /* 0x3edb6db7 */
@@ -49,8 +49,8 @@ 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 */
+cp_h = 9.6191406250e-01, /* 0x3f764000 =12b cp */
+cp_l = -1.1736857402e-04, /* 0xb8f623c6 =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*/
@@ -59,7 +59,7 @@ float
__ieee754_powf(float x, float y)
{
float z,ax,z_h,z_l,p_h,p_l;
- float yy1,t1,t2,r,s,t,u,v,w;
+ float yy1,t1,t2,r,s,sn,t,u,v,w;
int32_t i,j,k,yisint,n;
int32_t hx,hy,ix,iy,is;
@@ -70,10 +70,13 @@ __ieee754_powf(float x, float y)
/* y==zero: x**0 = 1 */
if(iy==0) return one;
- /* +-NaN return x+y */
+ /* x==1: 1**y = 1, even if y is NaN */
+ if (hx==0x3f800000) return one;
+
+ /* y!=zero: result is NaN if either arg is NaN */
if(ix > 0x7f800000 ||
iy > 0x7f800000)
- return x+y;
+ return (x+0.0F)+(y+0.0F);
/* determine if y is an odd int when x < 0
* yisint = 0 ... y is not an integer
@@ -84,8 +87,8 @@ __ieee754_powf(float x, float y)
if(hx<0) {
if(iy>=0x4b800000) yisint = 2; /* even integer y */
else if(iy>=0x3f800000) {
- k = (iy>>23)-0x7f; /* exponent */
- j = iy>>(23-k);
+ k = ((uint32_t)iy>>23)-0x7f; /* exponent */
+ j = (uint32_t)iy>>(23-k);
if((j<<(23-k))==iy) yisint = 2-(j&1);
}
}
@@ -93,7 +96,7 @@ __ieee754_powf(float x, float y)
/* special value of y */
if (iy==0x7f800000) { /* y is +-inf */
if (ix==0x3f800000)
- return y - y; /* inf**+-1 is NaN */
+ return one; /* (-1)**+-inf is NaN */
else if (ix > 0x3f800000)/* (|x|>1)**+-inf = inf,0 */
return (hy>=0)? y: zero;
else /* (|x|<1)**-,+inf = inf,0 */
@@ -122,17 +125,22 @@ __ieee754_powf(float x, float y)
return z;
}
+ n = ((u_int32_t)hx>>31)-1;
+
/* (x<0)**(non-int) is NaN */
- if(((((u_int32_t)hx>>31)-1)|yisint)==0) return (x-x)/(x-x);
+ if((n|yisint)==0) return (x-x)/(x-x);
+
+ sn = one; /* s (sign of result -ve**odd) = -1 else = 1 */
+ if((n|(yisint-1))==0) sn = -one;/* (-ve)**(odd int) */
/* |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;
+ if(ix<0x3f7ffff8) return (hy<0)? sn*huge*huge:sn*tiny*tiny;
+ if(ix>0x3f800007) return (hy>0)? sn*huge*huge:sn*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 = ax-one; /* t has 20 trailing zeros */
+ t = ax-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;
@@ -146,7 +154,7 @@ __ieee754_powf(float x, float y)
/* take care subnormal number */
if(ix<0x00800000)
{ax *= two24; n -= 24; GET_FLOAT_WORD(ix,ax); }
- n += ((ix)>>23)-0x7f;
+ n += (((uint32_t)ix)>>23)-0x7f;
j = ix&0x007fffff;
/* determine interval */
ix = j|0x3f800000; /* normalize ix */
@@ -163,7 +171,8 @@ __ieee754_powf(float x, float y)
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));
+ is = (((uint32_t)ix>>1)&0xfffff000)|0x20000000;
+ SET_FLOAT_WORD(t_h,is+0x00400000+(k<<21));
t_l = ax - (t_h-bp[k]);
s_l = v*((u-s_h*t_h)-s_h*t_l);
/* compute log(ax) */
@@ -193,10 +202,6 @@ __ieee754_powf(float x, float y)
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 yy1+y2 and compute (yy1+y2)*(t1+t2) */
GET_FLOAT_WORD(is,y);
SET_FLOAT_WORD(yy1,is&0xfffff000);
@@ -205,32 +210,32 @@ __ieee754_powf(float x, float y)
z = p_l+p_h;
GET_FLOAT_WORD(j,z);
if (j>0x43000000) /* if z > 128 */
- return s*huge*huge; /* overflow */
+ return sn*huge*huge; /* overflow */
else if (j==0x43000000) { /* if z == 128 */
- if(p_l+ovt>z-p_h) return s*huge*huge; /* overflow */
- }
- else if ((uint32_t)j==0xc3160000){ /* z == -150 */
- if(p_l<=z-p_h) return s*tiny*tiny; /* underflow */
+ if(p_l+ovt>z-p_h) return sn*huge*huge; /* overflow */
}
else if ((j&0x7fffffff)>0x43160000) /* z <= -150 */
- return s*tiny*tiny; /* underflow */
+ return sn*tiny*tiny; /* underflow */
+ else if (j==(int)0xc3160000){ /* z == -150 */
+ if(p_l<=z-p_h) return sn*tiny*tiny; /* underflow */
+ }
/*
* compute 2**(p_h+p_l)
*/
i = j&0x7fffffff;
- k = (i>>23)-0x7f;
+ k = ((uint32_t)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 */
+ k = (((uint32_t)n&0x7fffffff)>>23)-0x7f; /* new k for n */
SET_FLOAT_WORD(t,n&~(0x007fffff>>k));
- n = ((n&0x007fffff)|0x00800000)>>(23-k);
+ n = (((uint32_t)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);
+ SET_FLOAT_WORD(t,is&0xffff8000);
u = t*lg2_h;
v = (p_l-(t-p_h))*lg2+t*lg2_l;
z = u+v;
@@ -243,5 +248,5 @@ __ieee754_powf(float x, float y)
j += (n<<23);
if((j>>23)<=0) z = scalbnf(z,n); /* subnormal output */
else SET_FLOAT_WORD(z,j);
- return s*z;
+ return sn*z;
}
