GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libm/src/e_log10f.c Lines: 0 15 0.0 %
Date: 2017-11-13 Branches: 0 8 0.0 %

Line Branch Exec Source
1
/* e_log10f.c -- float version of e_log10.c.
2
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3
 */
4
5
/*
6
 * ====================================================
7
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8
 *
9
 * Developed at SunPro, a Sun Microsystems, Inc. business.
10
 * Permission to use, copy, modify, and distribute this
11
 * software is freely granted, provided that this notice
12
 * is preserved.
13
 * ====================================================
14
 */
15
16
#include "math.h"
17
#include "math_private.h"
18
19
static const float
20
two25      =  3.3554432000e+07, /* 0x4c000000 */
21
ivln10     =  4.3429449201e-01, /* 0x3ede5bd9 */
22
log10_2hi  =  3.0102920532e-01, /* 0x3e9a2080 */
23
log10_2lo  =  7.9034151668e-07; /* 0x355427db */
24
25
static const float zero   =  0.0;
26
27
float
28
log10f(float x)
29
{
30
	float y,z;
31
	int32_t i,k,hx;
32
33
	GET_FLOAT_WORD(hx,x);
34
35
        k=0;
36
        if (hx < 0x00800000) {                  /* x < 2**-126  */
37
            if ((hx&0x7fffffff)==0)
38
                return -two25/zero;             /* log(+-0)=-inf */
39
            if (hx<0) return (x-x)/zero;        /* log(-#) = NaN */
40
            k -= 25; x *= two25; /* subnormal number, scale up x */
41
	    GET_FLOAT_WORD(hx,x);
42
        }
43
	if (hx >= 0x7f800000) return x+x;
44
	k += (hx>>23)-127;
45
	i  = ((u_int32_t)k&0x80000000)>>31;
46
        hx = (hx&0x007fffff)|((0x7f-i)<<23);
47
        y  = (float)(k+i);
48
	SET_FLOAT_WORD(x,hx);
49
	z  = y*log10_2lo + ivln10*logf(x);
50
	return  z+y*log10_2hi;
51
}