f029f4be17
2012-11-01 Tobias Burnus <burnus@net-b.de>
* Makefile.am (libquadmath_la_SOURCES): Add new math/* files.
* Makefile.in: Regenerated.
* math/acoshq.c: Update comment.
* math/acosq.c: Ditto.
* math/asinhq.c: Ditto.
* math/asinq.c: Ditto.
* math/atan2q.c: Ditto.
* math/atanhq.c: Ditto.
* math/ceilq.c: Ditto.
* math/copysignq.c: Ditto.
* math/cosq.c: Ditto.
* math/coshq.c: Ditto.
* math/erfq.c: Ditto.
* math/fabsq.c: Ditto.
* math/finiteq.c: Ditto.
* math/floorq.c: Ditto.
* math/fmodq.c: Ditto.
* math/frexpq.c: Ditto.
* math/isnanq.c: Ditto.
* math/j0q.c: Ditto.
* math/j1q.c: Ditto.
* math/ldexpq.c: Ditto.
* math/llroundq.c: Ditto.
* math/log10q.c: Ditto.
* math/log1pq.c: Ditto.
* math/log2q.c: Ditto.
* math/logq.c: Ditto.
* math/lroundq.c: Ditto.
* math/modfq.c: Ditto.
* math/nextafterq.c: Ditto.
* math/powq.c: Ditto.
* math/rem_pio2q.c: Ditto.
* math/remainderq.c: Ditto.
* math/rintq.c: Ditto.
* math/roundq.c: Ditto.
* math/scalblnq.c: Ditto.
* math/scalbnq.c: Ditto.
* math/sincosq_kernel.c: Ditto.
* math/sinq.c: Ditto.
* math/tanq.c: Ditto.
* math/expq.c: Ditto.
(__expq_table, expq): Renamed local array from __expl_table.
* math/cosq_kernel.c (__quadmath_kernel_cosq): Fix sign
* handling.
* math/cacoshq.c: Changes from GLIBC; fix returned sign.
* math/casinhq.c: Changes from GLIBC to fix special-case.
* math/cbrtq.c: Use modified GLIBC version.
* math/complex.c (ccoshd, cexpq, clog10q, clogq, csinhq, csinq,
ctanhq, ctanq): Moved to separates files.
(mult_c128, div_c128): Removed no longer needed functions.
(cexpiq): Call sincosq instead of sinq and cosq.
(cosq): Call cosh(-re,im) instead of cosq/sinq/sinh/cosh.
* math/ccoshq.c (ccoshq): New file, moved from complex.c and
modified based on GLIBC.
* math/cexpq.c (cexp): Ditto.
* math/clog10q.c (clog10q): Ditto.
* math/clogq.c (clogq): Ditto.
* math/csinhq.c: Ditto.
* math/csinq.c: Ditto.
* math/csqrtq.c: Ditto.
* math/ctanhq.c: Ditto.
* math/ctanq.c: Ditto.
* math/fmaq.c (fmaq): Port TININESS_AFTER_ROUNDING handling
from GLIBC.
* math/ilogbq.c (ilogbq): Add errno = EDOM handling.
* math/isinf_nsq.c (__quadmath_isinf_nsq): New file, ported
from GLIBC.
* math/lgammaq.c (lgammaq): Add signgam handling.
* math/sinhq.c (sinhq): Fix sign handling.
* math/sinq_kernel.c (__quadmath_kernel_sinq): Ditto.
* math/tgammaq.c (tgammaq): Ditto.
* math/x2y2m1q.c: New file.
* quadmath-imp.h (TININESS_AFTER_ROUNDING): New define.
(__quadmath_x2y2m1q, __quadmath_isinf_nsq): New prototypes.
From-SVN: r193063
94 lines
2.8 KiB
C
94 lines
2.8 KiB
C
/* Compute x^2 + y^2 - 1, without large cancellation error.
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Copyright (C) 2012 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include "quadmath-imp.h"
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#include <stdlib.h>
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/* Calculate X + Y exactly and store the result in *HI + *LO. It is
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given that |X| >= |Y| and the values are small enough that no
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overflow occurs. */
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static inline void
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add_split (__float128 *hi, __float128 *lo, __float128 x, __float128 y)
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{
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/* Apply Dekker's algorithm. */
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*hi = x + y;
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*lo = (x - *hi) + y;
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}
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/* Calculate X * Y exactly and store the result in *HI + *LO. It is
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given that the values are small enough that no overflow occurs and
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large enough (or zero) that no underflow occurs. */
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static inline void
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mul_split (__float128 *hi, __float128 *lo, __float128 x, __float128 y)
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{
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/* Fast built-in fused multiply-add. */
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*hi = x * y;
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*lo = fmaq (x, y, -*hi);
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}
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/* Compare absolute values of floating-point values pointed to by P
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and Q for qsort. */
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static int
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compare (const void *p, const void *q)
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{
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__float128 pld = fabsq (*(const __float128 *) p);
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__float128 qld = fabsq (*(const __float128 *) q);
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if (pld < qld)
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return -1;
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else if (pld == qld)
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return 0;
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else
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return 1;
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}
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/* Return X^2 + Y^2 - 1, computed without large cancellation error.
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It is given that 1 > X >= Y >= epsilon / 2, and that either X >=
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0.75 or Y >= 0.5. */
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__float128
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__quadmath_x2y2m1q (__float128 x, __float128 y)
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{
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__float128 vals[4];
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size_t i;
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/* FIXME: SET_RESTORE_ROUNDL (FE_TONEAREST); */
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mul_split (&vals[1], &vals[0], x, x);
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mul_split (&vals[3], &vals[2], y, y);
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if (x >= 0.75Q)
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vals[1] -= 1.0Q;
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else
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{
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vals[1] -= 0.5Q;
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vals[3] -= 0.5Q;
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}
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qsort (vals, 4, sizeof (__float128), compare);
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/* Add up the values so that each element of VALS has absolute value
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at most equal to the last set bit of the next nonzero
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element. */
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for (i = 0; i <= 2; i++)
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{
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add_split (&vals[i + 1], &vals[i], vals[i + 1], vals[i]);
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qsort (vals + i + 1, 3 - i, sizeof (__float128), compare);
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}
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/* Now any error from this addition will be small. */
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return vals[3] + vals[2] + vals[1] + vals[0];
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}
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