a0ee07829a
This brings us up to date with FreeBSD HEAD, fixes various bugs, unifies the set of functions we support on ARM, MIPS, and x86, fixes "long double", adds ISO C99 support, and adds basic unit tests. It turns out that our "long double" functions have always been broken for non-normal numbers. This patch fixes that by not using the upstream implementations and just forwarding to the regular "double" implementation instead (since "long double" on Android is just "double" anyway, which is what BSD doesn't support). All the tests pass on ARM, MIPS, and x86, plus glibc on x86-64. Bug: 3169850 Bug: 8012787 Bug: https://code.google.com/p/android/issues/detail?id=6697 Change-Id: If0c343030959c24bfc50d4d21c9530052c581837
102 lines
3.4 KiB
C
102 lines
3.4 KiB
C
/*-
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* Copyright (c) 2007 David Schultz <das@FreeBSD.ORG>
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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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* 1. 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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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* 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 AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* Derived from s_modf.c, which has the following Copyright:
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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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* $FreeBSD$
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*/
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#include <float.h>
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#include <math.h>
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#include <sys/types.h>
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#include "fpmath.h"
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#if LDBL_MANL_SIZE > 32
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#define MASK ((uint64_t)-1)
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#else
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#define MASK ((uint32_t)-1)
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#endif
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/* Return the last n bits of a word, representing the fractional part. */
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#define GETFRAC(bits, n) ((bits) & ~(MASK << (n)))
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/* The number of fraction bits in manh, not counting the integer bit */
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#define HIBITS (LDBL_MANT_DIG - LDBL_MANL_SIZE)
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static const long double zero[] = { 0.0L, -0.0L };
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long double
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modfl(long double x, long double *iptr)
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{
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union IEEEl2bits ux;
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int e;
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ux.e = x;
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e = ux.bits.exp - LDBL_MAX_EXP + 1;
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if (e < HIBITS) { /* Integer part is in manh. */
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if (e < 0) { /* |x|<1 */
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*iptr = zero[ux.bits.sign];
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return (x);
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} else {
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if ((GETFRAC(ux.bits.manh, HIBITS - 1 - e) |
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ux.bits.manl) == 0) { /* X is an integer. */
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*iptr = x;
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return (zero[ux.bits.sign]);
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} else {
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/* Clear all but the top e+1 bits. */
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ux.bits.manh >>= HIBITS - 1 - e;
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ux.bits.manh <<= HIBITS - 1 - e;
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ux.bits.manl = 0;
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*iptr = ux.e;
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return (x - ux.e);
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}
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}
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} else if (e >= LDBL_MANT_DIG - 1) { /* x has no fraction part. */
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*iptr = x;
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if (x != x) /* Handle NaNs. */
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return (x);
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return (zero[ux.bits.sign]);
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} else { /* Fraction part is in manl. */
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if (GETFRAC(ux.bits.manl, LDBL_MANT_DIG - 1 - e) == 0) {
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/* x is integral. */
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*iptr = x;
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return (zero[ux.bits.sign]);
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} else {
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/* Clear all but the top e+1 bits. */
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ux.bits.manl >>= LDBL_MANT_DIG - 1 - e;
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ux.bits.manl <<= LDBL_MANT_DIG - 1 - e;
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*iptr = ux.e;
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return (x - ux.e);
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}
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}
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}
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