s_scalbnf.c - vx32 - Local 9vx git repository for patches.
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       ---
       s_scalbnf.c (1744B)
       ---
            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 #ifndef lint
           17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_scalbnf.c,v 1.7 2002/05/28 18:15:04 alfred Exp $";
           18 #endif
           19 
           20 #include "math.h"
           21 #include "math_private.h"
           22 
           23 static const float
           24 two25   =  3.355443200e+07,        /* 0x4c000000 */
           25 twom25  =  2.9802322388e-08,        /* 0x33000000 */
           26 huge   = 1.0e+30,
           27 tiny   = 1.0e-30;
           28 
           29 float
           30 scalbnf (float x, int n)
           31 {
           32         int32_t k,ix;
           33         GET_FLOAT_WORD(ix,x);
           34         k = (ix&0x7f800000)>>23;                /* extract exponent */
           35         if (k==0) {                                /* 0 or subnormal x */
           36             if ((ix&0x7fffffff)==0) return x; /* +-0 */
           37             x *= two25;
           38             GET_FLOAT_WORD(ix,x);
           39             k = ((ix&0x7f800000)>>23) - 25;
           40             if (n< -50000) return tiny*x;         /*underflow*/
           41             }
           42         if (k==0xff) return x+x;                /* NaN or Inf */
           43         k = k+n;
           44         if (k >  0xfe) return huge*copysignf(huge,x); /* overflow  */
           45         if (k > 0)                                 /* normal result */
           46             {SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;}
           47         if (k <= -25)
           48             if (n > 50000)         /* in case integer overflow in n+k */
           49                 return huge*copysignf(huge,x);        /*overflow*/
           50             else return tiny*copysignf(tiny,x);        /*underflow*/
           51         k += 25;                                /* subnormal result */
           52         SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23));
           53         return x*twom25;
           54 }