Log2 and log10 for wordsize-64.

This patch also fixes indentation on default dbl-64 code.
This commit is contained in:
Adhemerval Zanella 2012-05-14 16:49:42 -03:00
parent 02a9193863
commit 9ea01d93f7
5 changed files with 313 additions and 82 deletions

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@ -1,3 +1,11 @@
2012-05-15 Adhemerval Zanella <azanella@linux.vnet.ibm.com>
* sysdeps/ieee754/dbl-64/wordsize-64/e_log10.c: New file.
* sysdeps/ieee754/dbl-64/wordsize-64/e_log2.c: New file.
* sysdeps/ieee754/dbl-64/e_log2.c: Fixing indents.
* sysdeps/ieee754/dbl-64/e_log10.c: Likewise and also
remove unused global constant.
2012-05-15 Chris Metcalf <cmetcalf@tilera.com>
* sysdeps/unix/sysv/linux/getsysstats.c: Remove duplicate

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@ -46,39 +46,40 @@
#include <math.h>
#include <math_private.h>
static const double
two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
ivln10 = 4.34294481903251816668e-01, /* 0x3FDBCB7B, 0x1526E50E */
log10_2hi = 3.01029995663611771306e-01, /* 0x3FD34413, 0x509F6000 */
log10_2lo = 3.69423907715893078616e-13; /* 0x3D59FEF3, 0x11F12B36 */
static const double zero = 0.0;
static const double two54 = 1.80143985094819840000e+16; /* 0x43500000, 0x00000000 */
static const double ivln10 = 4.34294481903251816668e-01; /* 0x3FDBCB7B, 0x1526E50E */
static const double log10_2hi = 3.01029995663611771306e-01; /* 0x3FD34413, 0x509F6000 */
static const double log10_2lo = 3.69423907715893078616e-13; /* 0x3D59FEF3, 0x11F12B36 */
double
__ieee754_log10(double x)
__ieee754_log10 (double x)
{
double y,z;
int32_t i,k,hx;
u_int32_t lx;
double y, z;
int32_t i, k, hx;
u_int32_t lx;
EXTRACT_WORDS(hx,lx,x);
EXTRACT_WORDS (hx, lx, x);
k=0;
if (hx < 0x00100000) { /* x < 2**-1022 */
if (__builtin_expect(((hx&0x7fffffff)|lx)==0, 0))
return -two54/(x-x); /* log(+-0)=-inf */
if (__builtin_expect(hx<0, 0))
return (x-x)/(x-x); /* log(-#) = NaN */
k -= 54; x *= two54; /* subnormal number, scale up x */
GET_HIGH_WORD(hx,x);
}
if (__builtin_expect(hx >= 0x7ff00000, 0)) return x+x;
k += (hx>>20)-1023;
i = ((u_int32_t)k&0x80000000)>>31;
hx = (hx&0x000fffff)|((0x3ff-i)<<20);
y = (double)(k+i);
SET_HIGH_WORD(x,hx);
z = y*log10_2lo + ivln10*__ieee754_log(x);
return z+y*log10_2hi;
k = 0;
if (hx < 0x00100000)
{ /* x < 2**-1022 */
if (__builtin_expect (((hx & 0x7fffffff) | lx) == 0, 0))
return -two54 / (x - x); /* log(+-0)=-inf */
if (__builtin_expect (hx < 0, 0))
return (x - x) / (x - x); /* log(-#) = NaN */
k -= 54;
x *= two54; /* subnormal number, scale up x */
GET_HIGH_WORD (hx, x);
}
if (__builtin_expect (hx >= 0x7ff00000, 0))
return x + x;
k += (hx >> 20) - 1023;
i = ((u_int32_t) k & 0x80000000) >> 31;
hx = (hx & 0x000fffff) | ((0x3ff - i) << 20);
y = (double) (k + i);
SET_HIGH_WORD (x, hx);
z = y * log10_2lo + ivln10 * __ieee754_log (x);
return z + y * log10_2hi;
}
strong_alias (__ieee754_log10, __log10_finite)

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@ -57,64 +57,72 @@
#include <math.h>
#include <math_private.h>
static const double
ln2 = 0.69314718055994530942,
two54 = 1.80143985094819840000e+16, /* 43500000 00000000 */
Lg1 = 6.666666666666735130e-01, /* 3FE55555 55555593 */
Lg2 = 3.999999999940941908e-01, /* 3FD99999 9997FA04 */
Lg3 = 2.857142874366239149e-01, /* 3FD24924 94229359 */
Lg4 = 2.222219843214978396e-01, /* 3FCC71C5 1D8E78AF */
Lg5 = 1.818357216161805012e-01, /* 3FC74664 96CB03DE */
Lg6 = 1.531383769920937332e-01, /* 3FC39A09 D078C69F */
Lg7 = 1.479819860511658591e-01; /* 3FC2F112 DF3E5244 */
static const double ln2 = 0.69314718055994530942;
static const double two54 = 1.80143985094819840000e+16; /* 43500000 00000000 */
static const double Lg1 = 6.666666666666735130e-01; /* 3FE55555 55555593 */
static const double Lg2 = 3.999999999940941908e-01; /* 3FD99999 9997FA04 */
static const double Lg3 = 2.857142874366239149e-01; /* 3FD24924 94229359 */
static const double Lg4 = 2.222219843214978396e-01; /* 3FCC71C5 1D8E78AF */
static const double Lg5 = 1.818357216161805012e-01; /* 3FC74664 96CB03DE */
static const double Lg6 = 1.531383769920937332e-01; /* 3FC39A09 D078C69F */
static const double Lg7 = 1.479819860511658591e-01; /* 3FC2F112 DF3E5244 */
static const double zero = 0.0;
static const double zero = 0.0;
double
__ieee754_log2(double x)
__ieee754_log2 (double x)
{
double hfsq,f,s,z,R,w,t1,t2,dk;
int32_t k,hx,i,j;
u_int32_t lx;
double hfsq, f, s, z, R, w, t1, t2, dk;
int32_t k, hx, i, j;
u_int32_t lx;
EXTRACT_WORDS(hx,lx,x);
EXTRACT_WORDS (hx, lx, x);
k=0;
if (hx < 0x00100000) { /* x < 2**-1022 */
if (__builtin_expect(((hx&0x7fffffff)|lx)==0, 0))
return -two54/(x-x); /* log(+-0)=-inf */
if (__builtin_expect(hx<0, 0))
return (x-x)/(x-x); /* log(-#) = NaN */
k -= 54; x *= two54; /* subnormal number, scale up x */
GET_HIGH_WORD(hx,x);
}
if (__builtin_expect(hx >= 0x7ff00000, 0)) return x+x;
k += (hx>>20)-1023;
hx &= 0x000fffff;
i = (hx+0x95f64)&0x100000;
SET_HIGH_WORD(x,hx|(i^0x3ff00000)); /* normalize x or x/2 */
k += (i>>20);
dk = (double) k;
f = x-1.0;
if((0x000fffff&(2+hx))<3) { /* |f| < 2**-20 */
if(f==zero) return dk;
R = f*f*(0.5-0.33333333333333333*f);
return dk-(R-f)/ln2;
}
s = f/(2.0+f);
z = s*s;
i = hx-0x6147a;
w = z*z;
j = 0x6b851-hx;
t1= w*(Lg2+w*(Lg4+w*Lg6));
t2= z*(Lg1+w*(Lg3+w*(Lg5+w*Lg7)));
i |= j;
R = t2+t1;
if(i>0) {
hfsq=0.5*f*f;
return dk-((hfsq-(s*(hfsq+R)))-f)/ln2;
} else {
return dk-((s*(f-R))-f)/ln2;
}
k = 0;
if (hx < 0x00100000)
{ /* x < 2**-1022 */
if (__builtin_expect (((hx & 0x7fffffff) | lx) == 0, 0))
return -two54 / (x - x); /* log(+-0)=-inf */
if (__builtin_expect (hx < 0, 0))
return (x - x) / (x - x); /* log(-#) = NaN */
k -= 54;
x *= two54; /* subnormal number, scale up x */
GET_HIGH_WORD (hx, x);
}
if (__builtin_expect (hx >= 0x7ff00000, 0))
return x + x;
k += (hx >> 20) - 1023;
hx &= 0x000fffff;
i = (hx + 0x95f64) & 0x100000;
SET_HIGH_WORD (x, hx | (i ^ 0x3ff00000)); /* normalize x or x/2 */
k += (i >> 20);
dk = (double) k;
f = x - 1.0;
if ((0x000fffff & (2 + hx)) < 3)
{ /* |f| < 2**-20 */
if (f == zero)
return dk;
R = f * f * (0.5 - 0.33333333333333333 * f);
return dk - (R - f) / ln2;
}
s = f / (2.0 + f);
z = s * s;
i = hx - 0x6147a;
w = z * z;
j = 0x6b851 - hx;
t1 = w * (Lg2 + w * (Lg4 + w * Lg6));
t2 = z * (Lg1 + w * (Lg3 + w * (Lg5 + w * Lg7)));
i |= j;
R = t2 + t1;
if (i > 0)
{
hfsq = 0.5 * f * f;
return dk - ((hfsq - (s * (hfsq + R))) - f) / ln2;
}
else
{
return dk - ((s * (f - R)) - f) / ln2;
}
}
strong_alias (__ieee754_log2, __log2_finite)

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@ -0,0 +1,86 @@
/* @(#)e_log10.c 5.1 93/09/24 */
/*
* ====================================================
* 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.
* ====================================================
*/
/* __ieee754_log10(x)
* Return the base 10 logarithm of x
*
* Method :
* Let log10_2hi = leading 40 bits of log10(2) and
* log10_2lo = log10(2) - log10_2hi,
* ivln10 = 1/log(10) rounded.
* Then
* n = ilogb(x),
* if(n<0) n = n+1;
* x = scalbn(x,-n);
* log10(x) := n*log10_2hi + (n*log10_2lo + ivln10*log(x))
*
* Note 1:
* To guarantee log10(10**n)=n, where 10**n is normal, the rounding
* mode must set to Round-to-Nearest.
* Note 2:
* [1/log(10)] rounded to 53 bits has error .198 ulps;
* log10 is monotonic at all binary break points.
*
* Special cases:
* log10(x) is NaN with signal if x < 0;
* log10(+INF) is +INF with no signal; log10(0) is -INF with signal;
* log10(NaN) is that NaN with no signal;
* log10(10**N) = N for N=0,1,...,22.
*
* Constants:
* The hexadecimal values are the intended ones for the following constants.
* The decimal values may be used, provided that the compiler will convert
* from decimal to binary accurately enough to produce the hexadecimal values
* shown.
*/
#include <math.h>
#include <math_private.h>
static const double two54 = 1.80143985094819840000e+16; /* 0x4350000000000000 */
static const double ivln10 = 4.34294481903251816668e-01; /* 0x3FDBCB7B1526E50E */
static const double log10_2hi = 3.01029995663611771306e-01; /* 0x3FD34413509F6000 */
static const double log10_2lo = 3.69423907715893078616e-13; /* 0x3D59FEF311F12B36 */
double
__ieee754_log10 (double x)
{
double y, z;
int64_t i, hx;
int32_t k;
EXTRACT_WORDS64 (hx, x);
k = 0;
if (hx < INT64_C(0x0010000000000000))
{ /* x < 2**-1022 */
if (__builtin_expect ((hx & UINT64_C(0x7fffffffffffffff)) == 0, 0))
return -two54 / (x - x); /* log(+-0)=-inf */
if (__builtin_expect (hx < 0, 0))
return (x - x) / (x - x); /* log(-#) = NaN */
k -= 54;
x *= two54; /* subnormal number, scale up x */
EXTRACT_WORDS64 (hx, x);
}
/* scale up resulted in a NaN number */
if (__builtin_expect (hx >= UINT64_C(0x7ff0000000000000), 0))
return x + x;
k += (hx >> 52) - 1023;
i = ((uint64_t) k & UINT64_C(0x8000000000000000)) >> 63;
hx = (hx & UINT64_C(0x000fffffffffffff)) | ((0x3ff - i) << 52);
y = (double) (k + i);
INSERT_WORDS64 (x, hx);
z = y * log10_2lo + ivln10 * __ieee754_log (x);
return z + y * log10_2hi;
}
strong_alias (__ieee754_log10, __log10_finite)

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@ -0,0 +1,128 @@
/*
* ====================================================
* 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.
* ====================================================
*/
/* __ieee754_log2(x)
* Return the logarithm to base 2 of x
*
* Method :
* 1. Argument Reduction: find k and f such that
* x = 2^k * (1+f),
* where sqrt(2)/2 < 1+f < sqrt(2) .
*
* 2. Approximation of log(1+f).
* Let s = f/(2+f) ; based on log(1+f) = log(1+s) - log(1-s)
* = 2s + 2/3 s**3 + 2/5 s**5 + .....,
* = 2s + s*R
* We use a special Reme algorithm on [0,0.1716] to generate
* a polynomial of degree 14 to approximate R The maximum error
* of this polynomial approximation is bounded by 2**-58.45. In
* other words,
* 2 4 6 8 10 12 14
* R(z) ~ Lg1*s +Lg2*s +Lg3*s +Lg4*s +Lg5*s +Lg6*s +Lg7*s
* (the values of Lg1 to Lg7 are listed in the program)
* and
* | 2 14 | -58.45
* | Lg1*s +...+Lg7*s - R(z) | <= 2
* | |
* Note that 2s = f - s*f = f - hfsq + s*hfsq, where hfsq = f*f/2.
* In order to guarantee error in log below 1ulp, we compute log
* by
* log(1+f) = f - s*(f - R) (if f is not too large)
* log(1+f) = f - (hfsq - s*(hfsq+R)). (better accuracy)
*
* 3. Finally, log(x) = k + log(1+f).
* = k+(f-(hfsq-(s*(hfsq+R))))
*
* Special cases:
* log2(x) is NaN with signal if x < 0 (including -INF) ;
* log2(+INF) is +INF; log(0) is -INF with signal;
* log2(NaN) is that NaN with no signal.
*
* Constants:
* The hexadecimal values are the intended ones for the following
* constants. The decimal values may be used, provided that the
* compiler will convert from decimal to binary accurately enough
* to produce the hexadecimal values shown.
*/
#include <math.h>
#include <math_private.h>
static const double ln2 = 0.69314718055994530942;
static const double two54 = 1.80143985094819840000e+16; /* 4350000000000000 */
static const double Lg1 = 6.666666666666735130e-01; /* 3FE5555555555593 */
static const double Lg2 = 3.999999999940941908e-01; /* 3FD999999997FA04 */
static const double Lg3 = 2.857142874366239149e-01; /* 3FD2492494229359 */
static const double Lg4 = 2.222219843214978396e-01; /* 3FCC71C51D8E78AF */
static const double Lg5 = 1.818357216161805012e-01; /* 3FC7466496CB03DE */
static const double Lg6 = 1.531383769920937332e-01; /* 3FC39A09D078C69F */
static const double Lg7 = 1.479819860511658591e-01; /* 3FC2F112DF3E5244 */
static const double zero = 0.0;
double
__ieee754_log2 (double x)
{
double hfsq, f, s, z, R, w, t1, t2, dk;
int64_t hx, i, j;
int32_t k;
EXTRACT_WORDS64 (hx, x);
k = 0;
if (hx < INT64_C(0x0010000000000000))
{ /* x < 2**-1022 */
if (__builtin_expect ((hx & UINT64_C(0x7fffffffffffffff)) == 0, 0))
return -two54 / (x - x); /* log(+-0)=-inf */
if (__builtin_expect (hx < 0, 0))
return (x - x) / (x - x); /* log(-#) = NaN */
k -= 54;
x *= two54; /* subnormal number, scale up x */
EXTRACT_WORDS64 (hx, x);
}
if (__builtin_expect (hx >= UINT64_C(0x7ff0000000000000), 0))
return x + x;
k += (hx >> 52) - 1023;
hx &= UINT64_C(0x000fffffffffffff);
i = (hx + UINT64_C(0x95f6400000000)) & UINT64_C(0x10000000000000);
/* normalize x or x/2 */
INSERT_WORDS64 (x, hx | (i ^ UINT64_C(0x3ff0000000000000)));
k += (i >> 52);
dk = (double) k;
f = x - 1.0;
if ((UINT64_C(0x000fffffffffffff) & (2 + hx)) < 3)
{ /* |f| < 2**-20 */
if (f == zero)
return dk;
R = f * f * (0.5 - 0.33333333333333333 * f);
return dk - (R - f) / ln2;
}
s = f / (2.0 + f);
z = s * s;
i = hx - UINT64_C(0x6147a00000000);
w = z * z;
j = UINT64_C(0x6b85100000000) - hx;
t1 = w * (Lg2 + w * (Lg4 + w * Lg6));
t2 = z * (Lg1 + w * (Lg3 + w * (Lg5 + w * Lg7)));
i |= j;
R = t2 + t1;
if (i > 0)
{
hfsq = 0.5 * f * f;
return dk - ((hfsq - (s * (hfsq + R))) - f) / ln2;
}
else
{
return dk - ((s * (f - R)) - f) / ln2;
}
}
strong_alias (__ieee754_log2, __log2_finite)