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bb2376a6ed
nearbyint(), remquof(), remquo(), roundf(), round(), tgammaf(), tgamma(), truncf(), trunc(). Sort of implemented fmaf() and fma(), which really ought to be done in "SIMD" fashion. This completes the "real" floating point math library (ignoring for a moment that the floating point environment code is still not implemented). git-svn-id: file:///Users/olsen/Code/migration-svn-zu-git/logical-line-staging/clib2/trunk@15035 87f5fb63-7c3d-0410-a384-fd976d0f7a62
112 lines
3.6 KiB
C
Executable File
112 lines
3.6 KiB
C
Executable File
/*
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* $Id: math_lrintf.c,v 1.2 2005-10-09 10:38:55 obarthel Exp $
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*
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* :ts=4
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*
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* Portable ISO 'C' (1994) runtime library for the Amiga computer
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* Copyright (c) 2002-2005 by Olaf Barthel <olsen@sourcery.han.de>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* - Neither the name of Olaf Barthel nor the names of contributors
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* may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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*
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* PowerPC math library based in part on work by Sun Microsystems
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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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#ifndef _MATH_HEADERS_H
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#include "math_headers.h"
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#endif /* _MATH_HEADERS_H */
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/****************************************************************************/
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#if defined(FLOATING_POINT_SUPPORT)
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/****************************************************************************/
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/* Adding a float, x, to 2^23 will cause the result to be rounded based on
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the fractional part of x, according to the implementation's current rounding
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mode. 2^23 is the smallest float that can be represented using all 23 significant
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digits. */
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static const float TWO23[2]={
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8.3886080000e+06, /* 0x4b000000 */
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-8.3886080000e+06, /* 0xcb000000 */
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};
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/****************************************************************************/
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long int
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lrintf(float x)
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{
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LONG j0,sx;
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ULONG i0;
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float t;
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volatile float w;
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long int result;
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GET_FLOAT_WORD(i0,x);
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/* Extract sign bit. */
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sx = (i0 >> 31);
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/* Extract exponent field. */
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j0 = ((i0 & 0x7f800000) >> 23) - 127;
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if (j0 < (int)(sizeof (long int) * 8) - 1)
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{
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if (j0 < -1)
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return 0;
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else if (j0 >= 23)
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result = (long int) ((i0 & 0x7fffff) | 0x800000) << (j0 - 23);
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else
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{
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w = TWO23[sx] + x;
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t = w - TWO23[sx];
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GET_FLOAT_WORD (i0, t);
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/* Detect the all-zeros representation of plus and
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minus zero, which fails the calculation below. */
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if ((i0 & ~(1 << 31)) == 0)
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return 0;
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j0 = ((i0 >> 23) & 0xff) - 0x7f;
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i0 &= 0x7fffff;
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i0 |= 0x800000;
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result = i0 >> (23 - j0);
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}
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}
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else
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{
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return (long int) x;
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}
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return sx ? -result : result;
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}
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/****************************************************************************/
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#endif /* FLOATING_POINT_SUPPORT */
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