-/*
- * ====================================================
- * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
- *
- * Developed at SunPro, a Sun Microsystems, Inc. business.
- * Permission to use, copy, modify, and distribute this
- * software is freely granted, provided that this notice
- * is preserved.
- * ====================================================
- */
-
-/* __ieee754_acosh(x)
- * Method :
- * Based on
- * acosh(x) = log [ x + sqrt(x*x-1) ]
- * we have
- * acosh(x) := log(x)+ln2, if x is large; else
- * acosh(x) := log(2x-1/(sqrt(x*x-1)+x)) if x>2; else
- * acosh(x) := log1p(t+sqrt(2.0*t+t*t)); where t=x-1.
- *
- * Special cases:
- * acosh(x) is NaN with signal if x<1.
- * acosh(NaN) is NaN without signal.
- */
+/* Correctly-rounded inverse hyperbolic cosine function for the
+ binary64 floating point format.
+Copyright (c) 2023-2025 Alexei Sibidanov.
+
+The original version of this file was copied from the CORE-MATH
+project (file src/binary64/acosh/acosh.c, revision 69062c4d).
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE. */
+
+/* References:
+ [1] Tight and rigourous error bounds for basic building blocks of
+ double-word arithmetic, by Mioara Joldeş, Jean-Michel Muller,
+ and Valentina Popescu, ACM Transactions on Mathematical Software,
+ 44(2), 2017.
+ [2] Formalization of double-word arithmetic, and comments on ”Tight and
+ rigorous error bounds for basic building blocks of double-word
+ arithmetic”, Jean-Michel Muller, Laurence Rideau,
+ https://hal.science/hal-02972245v2, 2021.
+*/
+
+#include <array_length.h>
+#include <stdint.h>
#include <math.h>
-#include <math_private.h>
#include <libm-alias-finite.h>
+#include "math_config.h"
+
+static inline double
+fasttwosum (double x, double y, double *e)
+{
+ double s = x + y, z = s - x;
+ *e = y - z;
+ return s;
+}
+
+static inline double
+adddd (double xh, double xl, double ch, double cl, double *l)
+{
+ double s = xh + ch, d = s - xh;
+ *l = ((ch - d) + (xh + (d - s))) + (xl + cl);
+ return s;
+}
+
+/* This function implements Algorithm 10 (DWTimesDW1) from [1]
+ Its relative error (for round-to-nearest ties-to-even) is bounded by 5u^2
+ (Theorem 2.6 of [2]), where u = 2^-53 for double precision,
+ assuming xh = RN(xh + xl), which implies |xl| <= 1/2 ulp(xh),
+ and similarly for ch, cl. */
+static inline double
+muldd (double xh, double xl, double ch, double cl, double *l)
+{
+ double ahlh = ch * xl, alhh = cl * xh, ahhh = ch * xh,
+ ahhl = fma (ch, xh, -ahhh);
+ ahhl += alhh + ahlh;
+ ch = ahhh + ahhl;
+ *l = (ahhh - ch) + ahhl;
+ return ch;
+}
+
+static inline double
+mulddd (double xh, double xl, double ch, double *l)
+{
+ double ahlh = ch * xl, ahhh = ch * xh, ahhl = fma (ch, xh, -ahhh);
+ ahhl += ahlh;
+ ch = ahhh + ahhl;
+ *l = (ahhh - ch) + ahhl;
+ return ch;
+}
+
+static inline double
+polydd (double xh, double xl, int n, const double c[][2], double *l)
+{
+ int i = n - 1;
+ double ch = c[i][0] + *l, cl = ((c[i][0] - ch) + *l) + c[i][1];
+ while (--i >= 0)
+ {
+ ch = muldd (xh, xl, ch, cl, &cl);
+ double th = ch + c[i][0], tl = (c[i][0] - th) + ch;
+ ch = th;
+ cl += tl + c[i][1];
+ }
+ *l = cl;
+ return ch;
+}
+
+static double __attribute__ ((noinline)) as_acosh_refine (double, double);
+static double __attribute__ ((noinline))
+as_acosh_one (double x, double sh, double sl)
+{
+ static const double ch[][2]
+ = { { -0x1.5555555555555p-4, -0x1.5555555554af1p-58 },
+ { 0x1.3333333333333p-6, 0x1.9999998933f0ep-61 },
+ { -0x1.6db6db6db6db7p-8, 0x1.24929b16ec6b7p-63 },
+ { 0x1.f1c71c71c71c7p-10, 0x1.c56d45e265e2cp-66 },
+ { -0x1.6e8ba2e8ba2e9p-11, 0x1.6d50ce7188d3dp-65 },
+ { 0x1.1c4ec4ec4ec43p-12, 0x1.c6791d1cf399ap-66 },
+ { -0x1.c99999999914fp-14, 0x1.ee0d9408a2e2ap-68 },
+ { 0x1.7a878787648e2p-15, -0x1.1cea281e08012p-69 },
+ { -0x1.3fde50d0cb4b9p-16, 0x1.0335101403d9dp-72 },
+ { 0x1.12ef3bf8a0a74p-17, 0x1.f9c6b51787043p-80 } };
+
+ static const double cl[]
+ = { -0x1.df3b9d1296ea9p-19, 0x1.a681d7d2298ebp-20,
+ -0x1.77ead7b1ca449p-21, 0x1.4edd2ddb3721fp-22,
+ -0x1.1bf173531ee23p-23, 0x1.613229230e255p-25 };
+
+ double y2
+ = x
+ * (cl[0]
+ + x
+ * (cl[1]
+ + x * (cl[2] + x * (cl[3] + x * (cl[4] + x * (cl[5]))))));
+ double y1 = polydd (x, 0, 10, ch, &y2);
+ y1 = mulddd (y1, y2, x, &y2);
+ double y0 = fasttwosum (1, y1, &y1);
+ y1 += y2;
+ y0 = muldd (y0, y1, sh, sl, &y1);
+ return y0 + y1;
+}
-static const double
-one = 1.0,
-ln2 = 6.93147180559945286227e-01; /* 0x3FE62E42, 0xFEFA39EF */
+static const struct
+{
+ uint64_t c0;
+ short c1;
+} B[] = {
+ { 301, 27565 }, { 7189, 24786 }, { 13383, 22167 }, { 18923, 19696 },
+ { 23845, 17361 }, { 28184, 15150 }, { 31969, 13054 }, { 35231, 11064 },
+ { 37996, 9173 }, { 40288, 7372 }, { 42129, 5657 }, { 43542, 4020 },
+ { 44546, 2457 }, { 45160, 962 }, { 45399, -468 }, { 45281, -1838 },
+ { 44821, -3151 }, { 44032, -4412 }, { 42929, -5622 }, { 41522, -6786 },
+ { 39825, -7905 }, { 37848, -8982 }, { 35602, -10020 }, { 33097, -11020 },
+ { 30341, -11985 }, { 27345, -12916 }, { 24115, -13816 }, { 20661, -14685 },
+ { 16989, -15526 }, { 13107, -16339 }, { 9022, -17126 }, { 4740, -17889 }
+};
+static const double r1[]
+ = { 0x1p+0, 0x1.f5076p-1, 0x1.ea4bp-1, 0x1.dfc98p-1, 0x1.d5818p-1,
+ 0x1.cb72p-1, 0x1.c199cp-1, 0x1.b7f76p-1, 0x1.ae8ap-1, 0x1.a5504p-1,
+ 0x1.9c492p-1, 0x1.93738p-1, 0x1.8ace6p-1, 0x1.8258ap-1, 0x1.7a114p-1,
+ 0x1.71f76p-1, 0x1.6a09ep-1, 0x1.6247ep-1, 0x1.5ab08p-1, 0x1.5342cp-1,
+ 0x1.4bfdap-1, 0x1.44e08p-1, 0x1.3dea6p-1, 0x1.371a8p-1, 0x1.306fep-1,
+ 0x1.29e9ep-1, 0x1.2387ap-1, 0x1.1d488p-1, 0x1.172b8p-1, 0x1.11302p-1,
+ 0x1.0b558p-1, 0x1.059bp-1, 0x1p-1 };
+static const double r2[]
+ = { 0x1p+0, 0x1.ffa74p-1, 0x1.ff4eap-1, 0x1.fef62p-1, 0x1.fe9dap-1,
+ 0x1.fe452p-1, 0x1.fdeccp-1, 0x1.fd946p-1, 0x1.fd3c2p-1, 0x1.fce3ep-1,
+ 0x1.fc8bcp-1, 0x1.fc33ap-1, 0x1.fbdbap-1, 0x1.fb83ap-1, 0x1.fb2bcp-1,
+ 0x1.fad3ep-1, 0x1.fa7c2p-1, 0x1.fa246p-1, 0x1.f9ccap-1, 0x1.f975p-1,
+ 0x1.f91d8p-1, 0x1.f8c6p-1, 0x1.f86e8p-1, 0x1.f8172p-1, 0x1.f7bfep-1,
+ 0x1.f768ap-1, 0x1.f7116p-1, 0x1.f6ba4p-1, 0x1.f6632p-1, 0x1.f60c2p-1,
+ 0x1.f5b52p-1, 0x1.f55e4p-1, 0x1.f5076p-1 };
+static const double l1[][2] = { { 0x0p+0, 0x0p+0 },
+ { -0x1.269e2038315b3p-46, 0x1.62e4eacd4p-6 },
+ { -0x1.3f2558bddfc47p-45, 0x1.62e3ce7218p-5 },
+ { 0x1.07ea13c34efb5p-45, 0x1.0a2ab6d3ecp-4 },
+ { 0x1.8f3e77084d3bap-44, 0x1.62e4a86d8cp-4 },
+ { -0x1.8d92a005f1a7ep-46, 0x1.bb9db7062cp-4 },
+ { 0x1.58239e799bfe5p-44, 0x1.0a2b1a22ccp-3 },
+ { -0x1.a93fcf5f593b7p-44, 0x1.3687f0a298p-3 },
+ { -0x1.db4cac32fd2b5p-46, 0x1.62e4116b64p-3 },
+ { -0x1.0e65a92ee0f3bp-46, 0x1.8f409e4df6p-3 },
+ { -0x1.8261383d475f1p-44, 0x1.bb9d15001cp-3 },
+ { -0x1.359886207513bp-44, 0x1.e7f9a8c94p-3 },
+ { 0x1.811f87496ceb7p-44, 0x1.0a2b052ddbp-2 },
+ { 0x1.4991ec6cb435cp-44, 0x1.205955ef73p-2 },
+ { -0x1.4581abfeb8927p-44, 0x1.3687bd9121p-2 },
+ { 0x1.cab48f6942703p-44, 0x1.4cb5e8f2b5p-2 },
+ { -0x1.df2c452fde132p-47, 0x1.62e4420e2p-2 },
+ { 0x1.6109f4fdb74bdp-45, 0x1.791292c46ap-2 },
+ { -0x1.6b95fbdac7696p-44, 0x1.8f40af84e7p-2 },
+ { 0x1.7394fa880cbdap-46, 0x1.a56ed8f865p-2 },
+ { -0x1.50b06a94eccabp-46, 0x1.bb9d6505b4p-2 },
+ { -0x1.be2abf0b38989p-44, 0x1.d1cb91e728p-2 },
+ { -0x1.7d6bf1e34da04p-44, 0x1.e7f9d139e2p-2 },
+ { -0x1.423c1e14de6edp-44, 0x1.fe27db9b0ep-2 },
+ { 0x1.c46f1a0efbbc2p-44, 0x1.0a2b25060a8p-1 },
+ { 0x1.834fe4e3e6018p-45, 0x1.154244482ap-1 },
+ { 0x1.6a03d0f02b65p-46, 0x1.20597312988p-1 },
+ { 0x1.d437056526f3p-44, 0x1.2b707145dep-1 },
+ { -0x1.a0233728405c5p-45, 0x1.3687b0e0b28p-1 },
+ { -0x1.4dbdda10d2bf1p-45, 0x1.419ec5d3f68p-1 },
+ { 0x1.f7d0a25d154f2p-44, 0x1.4cb5f9fc02p-1 },
+ { 0x1.15ede4d803b18p-44, 0x1.57cd28421a8p-1 },
+ { 0x1.ef35793c7673p-45, 0x1.62e42fefa38p-1 } };
+static const double l2[][2] = { { 0x0p+0, 0x0p+0 },
+ { 0x1.5abdac3638e99p-44, 0x1.631ec81ep-11 },
+ { -0x1.16b8be9bbe239p-45, 0x1.62fd8127p-10 },
+ { -0x1.364c6315542ebp-44, 0x1.0a2520508p-9 },
+ { 0x1.734abe459c9p-45, 0x1.62dadc1dp-9 },
+ { 0x1.0cf8a761431bfp-44, 0x1.bb9ff94dp-9 },
+ { 0x1.da2718eb78708p-45, 0x1.0a2a2def8p-8 },
+ { 0x1.34ada62c59b93p-44, 0x1.368c0fae4p-8 },
+ { 0x1.d09ab376682d4p-44, 0x1.62e58e4f8p-8 },
+ { -0x1.3cb7b94329211p-45, 0x1.8f46bd28cp-8 },
+ { -0x1.eec5c297c41dp-45, 0x1.bb9f8312p-8 },
+ { -0x1.6411b9395d15p-44, 0x1.e7fff8f3p-8 },
+ { -0x1.1c0e59a43053cp-44, 0x1.0a2c0006ep-7 },
+ { 0x1.6506596e077b6p-46, 0x1.205bdb6fp-7 },
+ { 0x1.e256bce6faa27p-44, 0x1.36877c86ep-7 },
+ { 0x1.bd42467b0c8d1p-51, 0x1.4cb6f5578p-7 },
+ { -0x1.c4f92132ff0fp-44, 0x1.62e230e8cp-7 },
+ { -0x1.80be08bfab39p-44, 0x1.7911440f6p-7 },
+ { -0x1.f0b1319ceb1f7p-44, 0x1.8f443020ap-7 },
+ { 0x1.a65fcfb8de99bp-45, 0x1.a572dbef4p-7 },
+ { 0x1.4233885d3779cp-46, 0x1.bb9d449a6p-7 },
+ { 0x1.f46a59e646edbp-44, 0x1.d1cb8491cp-7 },
+ { -0x1.c3d2f11c11446p-44, 0x1.e7fd9d2aap-7 },
+ { 0x1.7763f78a1e0ccp-45, 0x1.fe2b6f978p-7 },
+ { 0x1.b4c37fc60c043p-44, 0x1.0a2a7c7a5p-6 },
+ { -0x1.5b8a822859be3p-46, 0x1.15412ca86p-6 },
+ { -0x1.f2d8c9fc064p-44, 0x1.2059c9005p-6 },
+ { -0x1.e80e79c20378dp-44, 0x1.2b703f49bp-6 },
+ { 0x1.68256e4329bdbp-44, 0x1.3688a1a8dp-6 },
+ { 0x1.7e9741da248c3p-44, 0x1.419edc7bap-6 },
+ { 0x1.e330dccce602bp-45, 0x1.4cb7034fap-6 },
+ { 0x1.2f32b5d18eefbp-49, 0x1.57cd01187p-6 },
+ { -0x1.269e2038315b3p-46, 0x1.62e4eacd4p-6 } };
+static const double c[] = { -0x1p-1, 0x1.555555555553p-2, -0x1.fffffffffffap-3,
+ 0x1.99999e33a6366p-3, -0x1.555559ef9525fp-3 };
double
__ieee754_acosh (double x)
{
- int64_t hx;
- EXTRACT_WORDS64 (hx, x);
+ uint64_t ix = asuint64 (x);
+ if (__glibc_unlikely (ix >= UINT64_C (0x7ff0000000000000)))
+ {
+ uint64_t aix = ix << 1;
+ if (ix == UINT64_C (0x7ff0000000000000)
+ || aix > (UINT64_C (0x7ff) << 53))
+ return x + x; /* +inf or nan */
+ return __math_invalid (x);
+ }
- if (hx > INT64_C (0x4000000000000000))
+ if (__glibc_unlikely (ix <= UINT64_C (0x3ff0000000000000)))
{
- if (__glibc_unlikely (hx >= INT64_C (0x41b0000000000000)))
+ if (ix == UINT64_C (0x3ff0000000000000))
+ return 0;
+ return __math_invalid (x);
+ }
+ double g;
+ int off = 0x3fe;
+ uint64_t t = ix;
+ if (ix < UINT64_C (0x3ff1e83e425aee63))
+ {
+ double z = x - 1;
+ double iz = (-0.25) / z, zt = 2 * z;
+ double sh = sqrt (zt),
+ sl = fma (sh, sh, -zt) * (sh * iz);
+ static const double cl[] = {
+ -0x1.5555555555555p-4, 0x1.3333333332f95p-6, -0x1.6db6db6d5534cp-8,
+ 0x1.f1c71c1e04356p-10, -0x1.6e8b8e3e40d58p-11, 0x1.1c4ba825ac4fep-12,
+ -0x1.c9045534e6d9ep-14, 0x1.71fedae26a76bp-15, -0x1.f1f4f8cc65342p-17
+ };
+ double z2 = z * z, z4 = z2 * z2,
+ ds = (sh * z)
+ * (cl[0]
+ + z
+ * (((cl[1] + z * cl[2]) + z2 * (cl[3] + z * cl[4]))
+ + z4
+ * ((cl[5] + z * cl[6])
+ + z2 * (cl[7] + z * cl[8]))));
+ double eps = ds * 0x1.04p-50 - 0x1p-104 * sh;
+ ds += sl;
+ double lb = sh + (ds - eps), ub = sh + (ds + eps);
+ if (lb == ub)
+ return lb;
+ return as_acosh_one (z, sh, sl);
+ }
+ else if (__glibc_likely (ix < UINT64_C (0x405bf00000000000)))
+ {
+ off = 0x3ff;
+ double x2h = x * x, wh = x2h - 1, wl = fma (x, x, -x2h);
+ double sh = sqrt (wh), ish = 0.5 / wh,
+ sl = (wl - fma (sh, sh, -wh)) * (sh * ish);
+ double tl, th = fasttwosum (x, sh, &tl);
+ tl += sl;
+ t = asuint64 (th);
+ g = tl / th;
+ }
+ else if (ix < UINT64_C (0x4087100000000000))
+ {
+ static const double cl[]
+ = { 0x1.5c4b6148816e2p-66, -0x1.000000000005cp-2,
+ -0x1.7fffffebf3e6cp-4, -0x1.aab6691f2bae7p-5 };
+ double z = 1 / (x * x);
+ g = cl[0] + z * (cl[1] + z * (cl[2] + z * cl[3]));
+ }
+ else if (ix < UINT64_C (0x40e0100000000000))
+ {
+ static const double cl[]
+ = { -0x1.7f77c8429c6c6p-67, -0x1.ffffffffff214p-3,
+ -0x1.8000268641bfep-4 };
+ double z = 1 / (x * x);
+ g = cl[0] + z * (cl[1] + z * cl[2]);
+ }
+ else if (ix < UINT64_C (0x41ea000000000000))
+ {
+ static const double cl[]
+ = { 0x1.7a0ed2effdd1p-67, -0x1.000000017d048p-2 };
+ double z = 1 / (x * x);
+ g = cl[0] + z * cl[1];
+ }
+ else
+ {
+ g = 0;
+ }
+ int ex = t >> 52, e = ex - off;
+ t &= ~UINT64_C (0) >> 12;
+ double ed = e;
+ uint64_t i = t >> (52 - 5);
+ int64_t d = t & (~UINT64_C (0) >> 17);
+ uint64_t j
+ = (t + ((uint64_t) B[i].c0 << 33) + ((int64_t) B[i].c1 * (d >> 16)))
+ >> (52 - 10);
+ t |= UINT64_C (0x3ff) << 52;
+ int i1 = j >> 5, i2 = j & 0x1f;
+ double r = r1[i1] * r2[i2], dx = fma (r, asdouble(t), -1), dx2 = dx * dx;
+ double f
+ = dx2 * ((c[0] + dx * c[1]) + dx2 * ((c[2] + dx * c[3]) + dx2 * c[4]));
+ const double l2h = 0x1.62e42fefa38p-1, l2l = 0x1.ef35793c7673p-45;
+ double lh = (l1[i1][1] + l2[i2][1]) + l2h * ed, ll = dx + l2l * ed;
+ ll += g;
+ ll += l1[i1][0] + l2[i2][0];
+ ll += f;
+ double eps = 2.8e-19;
+ double lb = lh + (ll - eps), ub = lh + (ll + eps);
+ if (__glibc_likely (lb == ub))
+ return lb;
+ return as_acosh_refine (x, 0x1.71547652b82fep+0 * lb);
+}
+libm_alias_finite (__ieee754_acosh, __acosh)
+
+static __attribute__ ((noinline)) double
+as_acosh_database (double x, double f)
+{
+ static const double db[][3] = {
+ { 0x1.5bff041b260fep+0, 0x1.a6031cd5f93bap-1, 0x1p-55 },
+ { 0x1.9efdca62b700ap+0, 0x1.104b648f113a1p+0, 0x1p-54 },
+ { 0x1.9efdca62b700ap+0, 0x1.104b648f113a1p+0, 0x1p-54 },
+ { 0x1.a5bf3acfde4b2p+0, 0x1.1585720f35cd9p+0, -0x1p-54 },
+ { 0x1.d888dd2101d93p+1, 0x1.faf8b7a12cf9fp+0, -0x1p-54 },
+ { 0x1.0151def34c2b8p+5, 0x1.0a7b6e3fed72p+2, 0x1p-52 },
+ { 0x1.45ea160ddc71fp+7, 0x1.725811dcf6782p+2, 0x1p-52 },
+ { 0x1.13570067acc9fp+9, 0x1.c04672343dccfp+2, -0x1p-52 },
+ { 0x1.2a686e4b567cep+10, 0x1.f1c928e7f1e65p+2, 0x1p-52 },
+ { 0x1.cb62eec26bd78p+15, 0x1.759a2ad4c4d56p+3, 0x1p-51 },
+ };
+ int a = 0, b = array_length (db) - 1, m = (a + b) / 2;
+ while (a <= b)
+ { /* binary search */
+ if (db[m][0] < x)
+ a = m + 1;
+ else if (db[m][0] == x)
{
- /* x > 2**28 */
- if (hx >= INT64_C (0x7ff0000000000000))
- /* x is inf of NaN */
- return x + x;
- else
- return __ieee754_log (x) + ln2;/* acosh(huge)=log(2x) */
+ f = db[m][1] + db[m][2];
+ break;
}
+ else
+ b = m - 1;
+ m = (a + b) / 2;
+ }
+ return f;
+}
- /* 2**28 > x > 2 */
- double t = x * x;
- return __ieee754_log (2.0 * x - one / (x + sqrt (t - one)));
+static double
+as_acosh_refine (double x, double a)
+{
+ static const double t1[]
+ = { 0x1p+0, 0x1.ea4afap-1, 0x1.d5818ep-1, 0x1.c199bep-1,
+ 0x1.ae89f98p-1, 0x1.9c4918p-1, 0x1.8ace54p-1, 0x1.7a1147p-1,
+ 0x1.6a09e68p-1, 0x1.5ab07ep-1, 0x1.4bfdad8p-1, 0x1.3dea65p-1,
+ 0x1.306fe08p-1, 0x1.2387a7p-1, 0x1.172b84p-1, 0x1.0b5587p-1,
+ 0x1p-1 };
+ static const double t2[]
+ = { 0x1p+0, 0x1.fe9d968p-1, 0x1.fd3c228p-1, 0x1.fbdba38p-1,
+ 0x1.fa7c18p-1, 0x1.f91d8p-1, 0x1.f7bfdbp-1, 0x1.f663278p-1,
+ 0x1.f507658p-1, 0x1.f3ac948p-1, 0x1.f252b38p-1, 0x1.f0f9c2p-1,
+ 0x1.efa1bfp-1, 0x1.ee4aaap-1, 0x1.ecf483p-1, 0x1.eb9f488p-1 };
+ static const double t3[]
+ = { 0x1p+0, 0x1.ffe9d2p-1, 0x1.ffd3a58p-1, 0x1.ffbd798p-1,
+ 0x1.ffa74e8p-1, 0x1.ff91248p-1, 0x1.ff7afb8p-1, 0x1.ff64d38p-1,
+ 0x1.ff4eac8p-1, 0x1.ff38868p-1, 0x1.ff22618p-1, 0x1.ff0c3dp-1,
+ 0x1.fef61ap-1, 0x1.fedff78p-1, 0x1.fec9d68p-1, 0x1.feb3b6p-1 };
+ static const double t4[]
+ = { 0x1p+0, 0x1.fffe9dp-1, 0x1.fffd3ap-1, 0x1.fffbd78p-1,
+ 0x1.fffa748p-1, 0x1.fff9118p-1, 0x1.fff7ae8p-1, 0x1.fff64cp-1,
+ 0x1.fff4e9p-1, 0x1.fff386p-1, 0x1.fff2238p-1, 0x1.fff0c08p-1,
+ 0x1.ffef5d8p-1, 0x1.ffedfa8p-1, 0x1.ffec98p-1, 0x1.ffeb35p-1 };
+ static const double LL[4][17][3] = {
+ {
+ { 0x0p+0, 0x0p+0, 0x0p+0 },
+ { 0x1.62e432b24p-6, -0x1.745af34bb54b8p-42, -0x1.17e3ec05cde7p-97 },
+ { 0x1.62e42e4a8p-5, 0x1.111a4eadf312p-44, 0x1.cff3027abb119p-93 },
+ { 0x1.0a2b233f1p-4, -0x1.88ac4ec78af8p-42, 0x1.4fa087ca75dfdp-93 },
+ { 0x1.62e43056cp-4, 0x1.6bd65e8b0b7p-46, -0x1.b18e160362c24p-95 },
+ { 0x1.bb9d3cbd6p-4, 0x1.de14aa55ec2bp-42, -0x1.c6ac3f1862a6bp-94 },
+ { 0x1.0a2b244dap-3, 0x1.94def487fea7p-42, -0x1.dead1a4581acfp-94 },
+ { 0x1.3687aa9b78p-3, 0x1.9cec9a50db22p-43, 0x1.34a70684f8e0ep-93 },
+ { 0x1.62e42fabap-3, -0x1.d69047a3aebp-44, -0x1.4e061f79144e2p-95 },
+ { 0x1.8f40b56d28p-3, 0x1.de7d755fd2e2p-42, 0x1.bdc7ecf001489p-94 },
+ { 0x1.bb9d3b61fp-3, 0x1.c14f1445b12p-46, 0x1.a1d78cbdc5b58p-93 },
+ { 0x1.e7f9c11f08p-3, -0x1.6e3e0000dae7p-43, 0x1.6a4559fadde98p-94 },
+ { 0x1.0a2b242ec4p-2, 0x1.bb7cf852a5fe8p-42, 0x1.a6aef11ee43bdp-93 },
+ { 0x1.205966c764p-2, 0x1.ad3a5f214294p-45, 0x1.5cc344fa10652p-93 },
+ { 0x1.3687a98aacp-2, 0x1.1623671842fp-45, -0x1.0b428fe1f9e43p-94 },
+ { 0x1.4cb5ec93f4p-2, 0x1.3d50980ea513p-42, 0x1.67f0ea083b1c4p-93 },
+ { 0x1.62e42fefa4p-2, -0x1.8432a1b0e264p-44, 0x1.803f2f6af40f3p-93 },
+ },
+ {
+ { 0x0p+0, 0x0p+0, 0x0p+0 },
+ { 0x1.62e462b4p-10, 0x1.061d003b97318p-42, 0x1.d7faee66a2e1ep-93 },
+ { 0x1.62e44c92p-9, 0x1.95a7bff5e239p-42, -0x1.f7e788a87135p-95 },
+ { 0x1.0a2b1e33p-8, 0x1.2a3a1a65aa3ap-43, -0x1.54599c9605442p-93 },
+ { 0x1.62e4367cp-8, -0x1.4a995b6d9ddcp-45, -0x1.56bb79b254f33p-100 },
+ { 0x1.bb9d449ap-8, 0x1.8a119c42e9bcp-42, -0x1.8ecf7d8d661f1p-93 },
+ { 0x1.0a2b1f19p-7, 0x1.8863771bd10a8p-42, 0x1.e9731de7f0155p-94 },
+ { 0x1.3687ad11p-7, 0x1.e026a347ca1c8p-42, 0x1.fadc62522444dp-97 },
+ { 0x1.62e436f28p-7, 0x1.25b84f71b70b8p-42, -0x1.fcb3f98612d27p-96 },
+ { 0x1.8f40b7b38p-7, -0x1.62a0a4fd4758p-43, 0x1.3cb3c35d9f6a1p-93 },
+ { 0x1.bb9d3abbp-7, -0x1.0ec48f94d786p-42, -0x1.6b47d410e4cc7p-93 },
+ { 0x1.e7f9bb23p-7, 0x1.e4415cbc97ap-43, -0x1.3729fdb677231p-93 },
+ { 0x1.0a2b22478p-6, -0x1.cb73f4505b03p-42, -0x1.1b3b3a3bc370ap-93 },
+ { 0x1.2059691e8p-6, -0x1.abcc3412f264p-43, -0x1.fe6e998e48673p-95 },
+ { 0x1.3687a768p-6, -0x1.43901e5c97a9p-42, 0x1.b54cdd52a5d88p-96 },
+ { 0x1.4cb5eb5d8p-6, -0x1.8f106f00f13b8p-42, -0x1.8f793f5fce148p-93 },
+ { 0x1.62e432b24p-6, -0x1.745af34bb54b8p-42, -0x1.17e3ec05cde7p-97 },
+ },
+ {
+ { 0x0p+0, 0x0p+0, 0x0p+0 },
+ { 0x1.62e7bp-14, -0x1.868625640a68p-44, -0x1.34bf0db910f65p-93 },
+ { 0x1.62e35f6p-13, -0x1.2ee3d96b696ap-43, 0x1.a2948cd558655p-94 },
+ { 0x1.0a2b4b2p-12, 0x1.53edbcf1165p-47, -0x1.cfc26ccf6d0e4p-97 },
+ { 0x1.62e4be1p-12, 0x1.783e334614p-52, -0x1.04b96da30e63ap-93 },
+ { 0x1.bb9e085p-12, -0x1.60785f20acb2p-43, -0x1.f33369bf7dff1p-96 },
+ { 0x1.0a2b94dp-11, 0x1.fd4b3a273353p-42, -0x1.685a35575eff1p-96 },
+ { 0x1.368810f8p-11, 0x1.7ded26dc813p-47, -0x1.4c4d1abca79bfp-96 },
+ { 0x1.62e47878p-11, 0x1.7d2bee9a1f63p-42, 0x1.860233b7ad13p-93 },
+ { 0x1.8f40cb48p-11, -0x1.af034eaf471cp-42, 0x1.ae748822d57b7p-94 },
+ { 0x1.bb9d094p-11, -0x1.7a223013a20fp-42, -0x1.1e499087075b6p-93 },
+ { 0x1.e7fa32c8p-11, -0x1.b2e67b1b59bdp-43, -0x1.54a41eda30fa6p-93 },
+ { 0x1.0a2b237p-10, -0x1.7ad97ff4ac7ap-44, 0x1.f932da91371ddp-93 },
+ { 0x1.2059a338p-10, -0x1.96422d90df4p-44, -0x1.90800fbbf2ed3p-94 },
+ { 0x1.36879824p-10, 0x1.0f9054001812p-44, 0x1.9567e01e48f9ap-93 },
+ { 0x1.4cb602cp-10, -0x1.0d709a5ec0b5p-43, 0x1.253dfd44635d2p-94 },
+ { 0x1.62e462b4p-10, 0x1.061d003b97318p-42, 0x1.d7faee66a2e1ep-93 },
+ },
+ {
+ { 0x0p+0, 0x0p+0, 0x0p+0 },
+ { 0x1.63007cp-18, -0x1.db0e38e5aaaap-43, 0x1.259a7b94815b9p-93 },
+ { 0x1.6300f6p-17, 0x1.2b1c75580438p-44, 0x1.78cabba01e3e4p-93 },
+ { 0x1.0a2115p-16, -0x1.5ff223730759p-42, 0x1.8074feacfe49dp-95 },
+ { 0x1.62e1ecp-16, -0x1.85d6f6487ce4p-45, 0x1.05485074b9276p-93 },
+ { 0x1.bba301p-16, -0x1.af5d58a7c921p-43, -0x1.30a8c0fd2ff5fp-93 },
+ { 0x1.0a32298p-15, 0x1.590faa0883bdp-43, 0x1.95e9bda999947p-93 },
+ { 0x1.3682f1p-15, 0x1.f0224376efaf8p-42, -0x1.5843c0db50d1p-93 },
+ { 0x1.62e3d8p-15, -0x1.142c13daed4ap-43, 0x1.c68a61183ce87p-93 },
+ { 0x1.8f44dd8p-15, -0x1.aa489f399931p-43, 0x1.11c5c376854eap-94 },
+ { 0x1.bb9601p-15, 0x1.9904d8b6a3638p-42, 0x1.8c89554493c8fp-93 },
+ { 0x1.e7f744p-15, 0x1.5785ddbe7cba8p-42, 0x1.e7ff3cde7d70cp-94 },
+ { 0x1.0a2c53p-14, -0x1.6d9e8780d0d5p-43, 0x1.ad9c178106693p-94 },
+ { 0x1.205d134p-14, -0x1.214a2e893fccp-43, 0x1.548a9500c9822p-93 },
+ { 0x1.3685e28p-14, 0x1.e23588646103p-43, 0x1.2a97b26da2d88p-94 },
+ { 0x1.4cb6c18p-14, 0x1.2b7cfcea9e0d8p-42, -0x1.5095048a6b824p-93 },
+ { 0x1.62e7bp-14, -0x1.868625640a68p-44, -0x1.34bf0db910f65p-93 },
+ },
+ };
+ static const double ch[][2] = {
+ { 0x1p-1, 0x1.24b67ee516e3bp-111 },
+ { -0x1p-2, -0x1.932ce43199a8dp-110 },
+ { 0x1.5555555555555p-3, 0x1.55540c15cf91fp-57 },
+ };
+ static const double cl[3]
+ = { -0x1p-3, 0x1.9999999a0754fp-4, -0x1.55555555c3157p-4 };
+ uint64_t ix = asuint64 (x);
+ double zh, zl;
+ if (ix < UINT64_C (0x4190000000000000))
+ {
+ double x2h = x * x, x2l = fma (x, x, -x2h);
+ double wl, wh = x2h - 1;
+ wh = fasttwosum (wh, x2l, &wl);
+ double sh = sqrt (wh), ish = 0.5 / wh,
+ sl = (ish * sh) * (wl - fma (sh, sh, -wh));
+ zh = fasttwosum (x, sh, &zl);
+ zl += sl;
+ zh = fasttwosum (zh, zl, &zl);
}
- else if (__glibc_likely (hx > INT64_C (0x3ff0000000000000)))
+ else if (ix < UINT64_C (0x4330000000000000))
{
- /* 1<x<2 */
- double t = x - one;
- return __log1p (t + sqrt (2.0 * t + t * t));
+ zh = 2 * x;
+ zl = -0.5 / x;
}
- else if (__glibc_likely (hx == INT64_C (0x3ff0000000000000)))
- return 0.0; /* acosh(1) = 0 */
- else /* x < 1 */
- return (x - x) / (x - x);
+ else
+ {
+ zh = x;
+ zl = 0;
+ }
+ uint64_t t = asuint64 (zh);
+ int ex = t >> 52, e = ex - 0x3ff + (zl == 0.0);
+ t &= ~UINT64_C (0) >> 12;
+ t |= UINT64_C (0x3ff) << 52;
+ double ed = e;
+ uint64_t v = asuint64 (a - ed + 0x1.00008p+0);
+ uint64_t i = (v - (UINT64_C (0x3ff) << 52)) >> (52 - 16);
+ int i1 = (i >> 12) & 0x1f, i2 = (i >> 8) & 0xf, i3 = (i >> 4) & 0xf,
+ i4 = i & 0xf;
+ const double l20 = 0x1.62e42fefa38p-2, l21 = 0x1.ef35793c768p-46,
+ l22 = -0x1.9ff0342542fc3p-91;
+ double el2 = l22 * ed, el1 = l21 * ed, el0 = l20 * ed;
+ double L[3];
+ L[0] = LL[0][i1][0] + LL[1][i2][0] + (LL[2][i3][0] + LL[3][i4][0]);
+ L[1] = LL[0][i1][1] + LL[1][i2][1] + (LL[2][i3][1] + LL[3][i4][1]);
+ L[2] = LL[0][i1][2] + LL[1][i2][2] + (LL[2][i3][2] + LL[3][i4][2]);
+ L[0] += el0;
+ double t12 = t1[i1] * t2[i2], t34 = t3[i3] * t4[i4];
+ double th = t12 * t34, tl = fma (t12, t34, -th);
+ double tf = asdouble (t);
+ double dh = th * tf, dl = fma (th, tf, -dh);
+ double sh = tl * tf, sl = fma (tl, tf, -sh);
+ double xl, xh = fasttwosum (dh - 1, dl, &xl);
+ if (zl != 0.0)
+ {
+ t = asuint64 (zl);
+ t -= (int64_t) e << 52;
+ xl += th * asdouble (t);
+ }
+ xh = adddd (xh, xl, sh, sl, &xl);
+ sl = xh * (cl[0] + xh * (cl[1] + xh * cl[2]));
+ sh = polydd (xh, xl, 3, ch, &sl);
+ sh = muldd (xh, xl, sh, sl, &sl);
+ sh = adddd (sh, sl, el1, el2, &sl);
+ sh = adddd (sh, sl, L[1], L[2], &sl);
+ double v2, v0 = fasttwosum (L[0], sh, &v2), v1 = fasttwosum (v2, sl, &v2);
+ v0 *= 2;
+ v1 *= 2;
+ v2 *= 2;
+ t = asuint64 (v1);
+ if (__glibc_unlikely (!(t & (~UINT64_C (0) >> 12))))
+ {
+ uint64_t w = asuint64 (v2);
+ if ((w ^ t) >> 63)
+ t--;
+ else
+ t++;
+ v1 = asdouble (t);
+ }
+ uint64_t t0 = asuint64 (v0);
+ uint64_t er = ((t + 7) & (~UINT64_C (0) >> 12)),
+ de = ((t0 >> 52) & 0x7ff) - ((t >> 52) & 0x7ff);
+ double res = v0 + v1;
+ if (__glibc_unlikely (de > 102 || er < 15))
+ return as_acosh_database (x, res);
+ return res;
}
-libm_alias_finite (__ieee754_acosh, __acosh)
projects / thirdparty / glibc.git / commitdiff
