ipiq: Add simple IPI latency measure sysctls (2)
[dragonfly.git] / lib / libm / src / s_scalbnf.c
CommitLineData
2fedfd5c
JM
1/* s_scalbnf.c -- float version of s_scalbn.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 * $FreeBSD: head/lib/msun/src/s_scalbnf.c 143205 2005-03-07 04:52:43Z das $
16 */
17
18
19#include "math.h"
20#include "math_private.h"
21
22static const float
23two25 = 3.355443200e+07, /* 0x4c000000 */
24twom25 = 2.9802322388e-08, /* 0x33000000 */
25huge = 1.0e+30,
26tiny = 1.0e-30;
27
28float
29scalbnf (float x, int n)
30{
31 int32_t k,ix;
32 GET_FLOAT_WORD(ix,x);
33 k = (ix&0x7f800000)>>23; /* extract exponent */
34 if (k==0) { /* 0 or subnormal x */
35 if ((ix&0x7fffffff)==0) return x; /* +-0 */
36 x *= two25;
37 GET_FLOAT_WORD(ix,x);
38 k = ((ix&0x7f800000)>>23) - 25;
39 if (n< -50000) return tiny*x; /*underflow*/
40 }
41 if (k==0xff) return x+x; /* NaN or Inf */
42 k = k+n;
43 if (k > 0xfe) return huge*copysignf(huge,x); /* overflow */
44 if (k > 0) /* normal result */
45 {SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;}
46 if (k <= -25)
47 if (n > 50000) /* in case integer overflow in n+k */
48 return huge*copysignf(huge,x); /*overflow*/
49 else return tiny*copysignf(tiny,x); /*underflow*/
50 k += 25; /* subnormal result */
51 SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23));
52 return x*twom25;
53}
54
55__strong_reference(scalbnf, ldexpf);