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4a1b96bf52
The left shift overflows for 'int', use uint64_t instead. It syncs with CORE-MATH commit 4d6192d2. Checked on aarch64-linux-gnu, x86_64-linux-gnu, and i686-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
96 lines
3.2 KiB
C
96 lines
3.2 KiB
C
/* Correctly-rounded hyperbolic cosine function for binary32 value.
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Copyright (c) 2022-2024 Alexei Sibidanov.
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The original version of this file was copied from the CORE-MATH
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project (file src/binary32/cosh/coshf.c, revision de59ecfb).
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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*/
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#include <stdint.h>
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#include <math.h>
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#include <libm-alias-finite.h>
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#include "math_config.h"
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#include "e_sincoshf_data.h"
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float
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__ieee754_coshf (float x)
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{
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const double iln2 = 0x1.71547652b82fep+5;
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double z = x;
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uint32_t ax = asuint (x) << 1;
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if (__glibc_unlikely (ax > 0x8565a9f8u))
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{ /* |x| >~ 89.4 */
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if (ax >= 0xff000000u)
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{
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if (ax << 8)
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return x + x; /* nan */
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return INFINITY; /* +-inf */
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}
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return __math_oflowf (0);
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}
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if (__glibc_unlikely (ax < 0x7c000000u))
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{ /* |x| < 0.125 */
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if (__glibc_unlikely (ax < 0x74000000u))
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{ /* |x| < 0x1p-11 */
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if (__glibc_unlikely (ax < 0x66000000u)) /* |x| < 0x1p-24 */
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return fmaf (fabsf (x), 0x1p-25, 1.0f);
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return (0.5f * x) * x + 1.0f;
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}
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static const double cp[] =
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{
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0x1.fffffffffffe3p-2, 0x1.55555555723cfp-5,
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0x1.6c16bee4a5986p-10, 0x1.a0483fc0328f7p-16
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};
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double z2 = z * z;
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double z4 = z2 * z2;
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return 1.0 + z2 * ((cp[0] + z2 * cp[1]) + z4 * (cp[2] + z2 * (cp[3])));
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}
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double a = iln2 * z;
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double ia = roundeven_finite (a);
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double h = a - ia;
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double h2 = h * h;
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int64_t jp = asuint64 (ia + 0x1.8p52);
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int64_t jm = -jp;
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double sp = asdouble (TB[jp & 31] + ((uint64_t)(jp >> 5) << 52));
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double sm = asdouble (TB[jm & 31] + ((uint64_t)(jm >> 5) << 52));
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double te = C[0] + h2 * C[2];
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double to = (C[1] + h2 * C[3]);
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double rp = sp * (te + h * to);
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double rm = sm * (te - h * to);
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double r = rp + rm;
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float ub = r;
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double lb = r - 1.45e-10 * r;
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if (__glibc_unlikely (ub != lb))
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{
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const double iln2h = 0x1.7154765p+5;
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const double iln2l = 0x1.5c17f0bbbe88p-26;
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h = (iln2h * z - ia) + iln2l * z;
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h2 = h * h;
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te = CH[0] + h2 * CH[2] + (h2 * h2) * (CH[4] + h2 * CH[6]);
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to = CH[1] + h2 * (CH[3] + h2
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* CH[5]);
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r = sp * (te + h * to) + sm * (te - h * to);
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ub = r;
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}
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return ub;
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}
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libm_alias_finite (__ieee754_coshf, __coshf)
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