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
16 #include "fdlibm.h"
17
18 static const float
19 two25 = 3.355443200e+07, /* 0x4c000000 */
20 twom25 = 2.9802322388e-08; /* 0x33000000 */
21
22 float
scalblnf(float x,long int n)23 scalblnf (float x, long int n)
24 {
25 __int32_t ix;
26 uint32_t hx;
27 long int k;
28
29 GET_FLOAT_WORD(ix,x);
30 hx = ix&0x7fffffff;
31 k = hx>>23; /* extract exponent */
32 if (k==0) { /* 0 or subnormal x */
33 if (hx == 0) return x; /* +-0 */
34 x *= two25;
35 GET_FLOAT_WORD(ix,x);
36 k = ((ix&0x7f800000)>>23) - 25;
37 if (n< -50000)
38 return __math_uflowf(ix<0); /*underflow*/
39 }
40 if (k==0xff) return x+x; /* NaN or Inf */
41 k = k+n;
42 if (n> 50000 || k > 0xfe)
43 return __math_oflowf(ix < 0); /* overflow */
44 if (k > 0) /* normal result */
45 {SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;}
46 if (k <= -25)
47 return __math_uflowf(ix < 0); /*underflow*/
48 k += 25; /* subnormal result */
49 SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23));
50 return check_uflowf(x*twom25);
51 }
52
53 _MATH_ALIAS_f_fj(scalbln)
54
