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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4973 | right-hear | 1 | /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */ |
| 2 | /* s_frexpf.c -- float version of s_frexp.c. |
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| 3 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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| 4 | */ |
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| 5 | |||
| 6 | /* |
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| 7 | * ==================================================== |
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| 8 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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| 9 | * |
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| 10 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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| 11 | * Permission to use, copy, modify, and distribute this |
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| 12 | * software is freely granted, provided that this notice |
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| 13 | * is preserved. |
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| 14 | * ==================================================== |
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| 15 | */ |
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| 16 | |||
| 17 | #if defined(LIBM_SCCS) && !defined(lint) |
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| 18 | static char rcsid[] = "$Id: s_frexpf.c,v 1.2 1994/08/18 23:06:51 jtc Exp $"; |
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| 19 | #endif |
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| 20 | |||
| 21 | #include "math.h" |
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| 22 | #include "math_private.h" |
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| 23 | |||
| 24 | #ifdef __STDC__ |
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| 25 | static const float |
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| 26 | #else |
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| 27 | static float |
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| 28 | #endif |
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| 29 | one = 1.0000000000e+00, /* 0x3F800000 */ |
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| 30 | two25 = 3.3554432000e+07; /* 0x4c000000 */ |
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| 31 | |||
| 32 | #ifdef __STDC__ |
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| 33 | float frexpf(float x, int *eptr) |
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| 34 | #else |
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| 35 | float frexpf(x, eptr) |
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| 36 | float x; int *eptr; |
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| 37 | #endif |
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| 38 | { |
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| 39 | int32_t hx,ix; |
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| 40 | GET_FLOAT_WORD(hx,x); |
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| 41 | ix = 0x7fffffff&hx; |
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| 42 | *eptr = 0; |
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| 43 | if(ix>=0x7f800000||(ix==0)) return x; /* 0,inf,nan */ |
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| 44 | if (ix<0x00800000) { /* subnormal */ |
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| 45 | x *= two25; |
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| 46 | GET_FLOAT_WORD(hx,x); |
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| 47 | ix = hx&0x7fffffff; |
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| 48 | *eptr = -25; |
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| 49 | } |
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| 50 | *eptr += (ix>>23)-126; |
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| 51 | hx = (hx&0x807fffff)|0x3f000000; |
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| 52 | *(int*)&x = hx; |
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| 53 | return x; |
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| 54 | } |