5980be9b3c
This work is based in part on code from NetBSD libm, libc and kernel. The library is partly public domain and partly BSD-style licensed.
41 lines
1 KiB
C
41 lines
1 KiB
C
/* s_ilogbf.c -- float version of s_ilogb.c.
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include <sys/cdefs.h>
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#if defined(LIBM_SCCS) && !defined(lint)
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__RCSID("$NetBSD: s_ilogbf.c,v 1.7 2002/05/26 22:01:56 wiz Exp $");
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#endif
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#include "math.h"
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#include "math_private.h"
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int
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ilogbf(float x)
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{
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int32_t hx,ix;
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GET_FLOAT_WORD(hx,x);
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hx &= 0x7fffffff;
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if(hx<0x00800000) {
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if(hx==0)
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return 0x80000001; /* ilogb(0) = 0x80000001 */
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else /* subnormal x */
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for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1;
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return ix;
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}
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else if (hx<0x7f800000) return (hx>>23)-127;
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else return 0x7fffffff;
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}
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