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Last change
on this file was 2006, checked in by bird, 20 years ago |
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Initial revision
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Property cvs2svn:cvs-rev
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1.1
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Property svn:eol-style
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native
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Property svn:executable
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*
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File size:
932 bytes
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| 1 | /* s_logbf.c -- float version of s_logb.c.
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| 2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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| 3 | */
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| 4 |
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| 5 | /*
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| 6 | * ====================================================
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| 7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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| 8 | *
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| 9 | * Developed at SunPro, a Sun Microsystems, Inc. business.
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| 10 | * Permission to use, copy, modify, and distribute this
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| 11 | * software is freely granted, provided that this notice
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| 12 | * is preserved.
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| 13 | * ====================================================
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| 14 | */
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| 15 |
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| 16 | #ifndef lint
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| 17 | static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_logbf.c,v 1.7 2002/05/28 18:15:04 alfred Exp $";
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| 18 | #endif
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| 19 |
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| 20 | #include "math.h"
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| 21 | #include "math_private.h"
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| 22 |
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| 23 | float
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| 24 | logbf(float x)
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| 25 | {
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| 26 | int32_t ix;
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| 27 | GET_FLOAT_WORD(ix,x);
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| 28 | ix &= 0x7fffffff; /* high |x| */
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| 29 | if(ix==0) return (float)-1.0/fabsf(x);
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| 30 | if(ix>=0x7f800000) return x*x;
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| 31 | if((ix>>=23)==0) /* IEEE 754 logb */
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| 32 | return -126.0;
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| 33 | else
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| 34 | return (float) (ix-127);
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| 35 | }
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