1 /* origin: FreeBSD /usr/src/lib/msun/src/s_scalbnf.c */
3 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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
13 * ====================================================
19 two25 = 3.355443200e+07, /* 0x4c000000 */
20 twom25 = 2.9802322388e-08, /* 0x33000000 */
24 float scalbnf(float x, int n)
27 GET_FLOAT_WORD(ix, x);
28 k = (ix&0x7f800000)>>23; /* extract exponent */
29 if (k == 0) { /* 0 or subnormal x */
30 if ((ix&0x7fffffff) == 0) /* +-0 */
33 GET_FLOAT_WORD(ix, x);
34 k = ((ix&0x7f800000)>>23) - 25;
36 return tiny*x; /*underflow*/
38 if (k == 0xff) /* NaN or Inf */
42 return huge*copysignf(huge, x); /* overflow */
43 if (k > 0) { /* normal result */
44 SET_FLOAT_WORD(x, (ix&0x807fffff)|(k<<23));
48 if (n > 50000) /* in case integer overflow in n+k */
49 return huge*copysignf(huge,x); /*overflow*/
50 return tiny*copysignf(tiny, x); /*underflow*/
51 k += 25; /* subnormal result */
52 SET_FLOAT_WORD(x, (ix&0x807fffff)|(k<<23));