--- /dev/null
+/* Correctly-rounded biased argument base-10 logarithm function for binary32 value.
+
+Copyright (c) 2022-2023 Alexei Sibidanov.
+
+This file is part of the CORE-MATH project
+project (file src/binary32/log10p1/log10p1f.c revision bc385c2).
+
+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.
+*/
+
+#include <stdint.h>
+#include <errno.h>
+#include <fenv.h>
+#include <libm-alias-float.h>
+#include "math_config.h"
+
+static __attribute__ ((noinline)) float
+as_special (float x)
+{
+ uint32_t ux = asuint (x);
+ if (ux == 0x7f800000u)
+ return x; /* +inf */
+ uint32_t ax = ux << 1;
+ if (ax == 0x17fu << 24)
+ /* x+1 = 0.0 */
+ return __math_divzerof (1);
+ if (ax > 0xff000000u)
+ return x + x; /* nan */
+ return __math_invalidf (x);
+}
+
+float
+__log10p1f (float x)
+{
+ static const double tr[] =
+ {
+ 0x1p+0, 0x1.f81f82p-1, 0x1.f07c1fp-1, 0x1.e9131acp-1,
+ 0x1.e1e1e1ep-1, 0x1.dae6077p-1, 0x1.d41d41dp-1, 0x1.cd85689p-1,
+ 0x1.c71c71cp-1, 0x1.c0e0704p-1, 0x1.bacf915p-1, 0x1.b4e81b5p-1,
+ 0x1.af286bdp-1, 0x1.a98ef6p-1, 0x1.a41a41ap-1, 0x1.9ec8e95p-1,
+ 0x1.999999ap-1, 0x1.948b0fdp-1, 0x1.8f9c19p-1, 0x1.8acb90fp-1,
+ 0x1.8618618p-1, 0x1.8181818p-1, 0x1.7d05f41p-1, 0x1.78a4c81p-1,
+ 0x1.745d174p-1, 0x1.702e05cp-1, 0x1.6c16c17p-1, 0x1.6816817p-1,
+ 0x1.642c859p-1, 0x1.605816p-1, 0x1.5c9882cp-1, 0x1.58ed231p-1,
+ 0x1.5555555p-1, 0x1.51d07ebp-1, 0x1.4e5e0a7p-1, 0x1.4afd6ap-1,
+ 0x1.47ae148p-1, 0x1.446f865p-1, 0x1.4141414p-1, 0x1.3e22cbdp-1,
+ 0x1.3b13b14p-1, 0x1.3813814p-1, 0x1.3521cfbp-1, 0x1.323e34ap-1,
+ 0x1.2f684bep-1, 0x1.2c9fb4ep-1, 0x1.29e412ap-1, 0x1.27350b9p-1,
+ 0x1.2492492p-1, 0x1.21fb781p-1, 0x1.1f7047ep-1, 0x1.1cf06aep-1,
+ 0x1.1a7b961p-1, 0x1.1811812p-1, 0x1.15b1e5fp-1, 0x1.135c811p-1,
+ 0x1.1111111p-1, 0x1.0ecf56cp-1, 0x1.0c9715p-1, 0x1.0a6810ap-1,
+ 0x1.0842108p-1, 0x1.0624dd3p-1, 0x1.041041p-1, 0x1.0204081p-1,
+ 0.5
+ };
+ static const double tl[] =
+ {
+ 0x1.562ec497ef351p-43, 0x1.b9476892ea99cp-8, 0x1.b5e909c959eecp-7,
+ 0x1.45f4f59ec84fp-6, 0x1.af5f92cbcf2aap-6, 0x1.0ba01a6069052p-5,
+ 0x1.3ed119b99dd41p-5, 0x1.714834298a088p-5, 0x1.a30a9d98309c1p-5,
+ 0x1.d41d51266b9d9p-5, 0x1.02428c0f62dfcp-4, 0x1.1a23444eea521p-4,
+ 0x1.31b30543f2597p-4, 0x1.48f3ed39bd5e7p-4, 0x1.5fe8049a0bd06p-4,
+ 0x1.769140a6a78eap-4, 0x1.8cf1836c96595p-4, 0x1.a30a9d5551a84p-4,
+ 0x1.b8de4d1ee5b21p-4, 0x1.ce6e4202c7bc9p-4, 0x1.e3bc1accaa6eap-4,
+ 0x1.f8c9683b584b7p-4, 0x1.06cbd68ca86ep-3, 0x1.11142f19de3a2p-3,
+ 0x1.1b3e71fa795fp-3, 0x1.254b4d37a3354p-3, 0x1.2f3b6912cab79p-3,
+ 0x1.390f6831144f7p-3, 0x1.42c7e7fffb21ap-3, 0x1.4c65808c779aep-3,
+ 0x1.55e8c507508c7p-3, 0x1.5f52445deb049p-3, 0x1.68a288c3efe72p-3,
+ 0x1.71da17bdef98bp-3, 0x1.7af9736089c4bp-3, 0x1.84011952a11ebp-3,
+ 0x1.8cf1837a7d6d1p-3, 0x1.95cb2891e3048p-3, 0x1.9e8e7b0f85651p-3,
+ 0x1.a73beaa5d9dfep-3, 0x1.afd3e39454544p-3, 0x1.b856cf060c662p-3,
+ 0x1.c0c5134de0c6dp-3, 0x1.c91f1371bb611p-3, 0x1.d1652ffcd2bc5p-3,
+ 0x1.d997c6f634ae6p-3, 0x1.e1b733ab8fbadp-3, 0x1.e9c3ceadab4c8p-3,
+ 0x1.f1bdeec438f77p-3, 0x1.f9a5e7a5f906fp-3, 0x1.00be05ac02564p-2,
+ 0x1.04a054d81990cp-2, 0x1.087a083594e33p-2, 0x1.0c4b457098b4fp-2,
+ 0x1.101431aa1f48ap-2, 0x1.13d4f08b98411p-2, 0x1.178da53edaecbp-2,
+ 0x1.1b3e71e9f9391p-2, 0x1.1ee777defd526p-2, 0x1.2288d7b48d874p-2,
+ 0x1.2622b0f52dad8p-2, 0x1.29b522a4c594cp-2, 0x1.2d404b0e305b9p-2,
+ 0x1.30c4478f3f21dp-2, 0x1.34413509f6f4dp-2
+ };
+ static const union
+ {
+ float f;
+ uint32_t u;
+ } st[] =
+ {
+ { 0x0p+0 }, { 0x1.2p+3 }, { 0x1.8cp+6 },
+ { 0x1.f38p+9 }, { 0x1.3878p+13 }, { 0x1.869fp+16 },
+ { 0x1.e847ep+19 }, { 0x1.312cfep+23 }
+ };
+ double z = x;
+ uint32_t ux = asuint (x);
+ if (__glibc_unlikely (ux >= 0x17fu << 23)) /* x <= -1 */
+ return as_special (x);
+ uint32_t ax = ux & (~0u >> 1);
+ if (__glibc_unlikely (ax == 0))
+ return copysign (0, x);
+ if (__glibc_unlikely (ax >= (0xff << 23))) /* +inf, nan */
+ return as_special (x);
+ int ie = ux;
+ ie >>= 23;
+ unsigned int je = ie - 126;
+ je = (je * 0x9a209a8) >> 29;
+ if (__glibc_unlikely (ux == st[je].u))
+ return je;
+
+ uint64_t tz = asuint64 (z + 1.0);
+ uint64_t m = tz & (~(uint64_t) 0 >> 12);
+ int32_t e = (tz >> 52) - 1023, j = ((m + ((int64_t) 1 << 45)) >> 46);
+ tz = m | ((uint64_t) 0x3ff << 52);
+ double ix = tr[j], l = tl[j];
+ double off = e * 0x1.34413509f79ffp-2 + l;
+ double v = asdouble (tz) * ix - 1;
+
+ static const double h[] =
+ {
+ 0x1.bcb7b150bf6d8p-2, -0x1.bcb7b1738c07ep-3,
+ 0x1.287de19e795c5p-3, -0x1.bca44edc44bc4p-4
+ };
+ double v2 = v * v;
+ double f = (h[0] + v * h[1]) + v2 * (h[2] + v * h[3]);
+ double r = off + v * f;
+ float ub = r;
+ float lb = r + 0x1.5cp-42;
+ if (__glibc_unlikely (ub != lb))
+ {
+ if (__glibc_unlikely (ax < 0x3d32743eu))
+ { /* 0x1.64e87cp-5f */
+ if (__glibc_unlikely (ux == 0xa6aba8afu))
+ return -0x1.2a33bcp-51f + 0x1p-76f;
+ if (__glibc_unlikely (ux == 0xaf39b9a7u))
+ return -0x1.42a342p-34f + 0x1p-59f;
+ if (__glibc_unlikely (ux == 0x399a7c00u))
+ return 0x1.0c53cap-13f + 0x1p-38f;
+ z /= 2.0 + z;
+ double z2 = z * z, z4 = z2 * z2;
+ static const double c[] =
+ {
+ 0x1.bcb7b1526e50fp-1, 0x1.287a76370129dp-2,
+ 0x1.63c62378fa3dbp-3, 0x1.fca4139a42374p-4
+ };
+ float ret = z * ((c[0] + z2 * c[1]) + z4 * (c[2] + z2 * c[3]));
+ if (x != 0.0f && ret == 0.0)
+ __set_errno (ERANGE);
+ return ret;
+ }
+ if (__glibc_unlikely (ux == 0x7956ba5eu))
+ return 0x1.16bebap+5f + 0x1p-20f;
+ if (__glibc_unlikely (ux == 0xbd86ffb9u))
+ return -0x1.e53536p-6f + 0x1p-31f;
+ static const double c[] =
+ {
+ 0x1.bcb7b1526e50ep-2, -0x1.bcb7b1526e53dp-3, 0x1.287a7636f3fa2p-3,
+ -0x1.bcb7b146a14b3p-4, 0x1.63c627d5219cbp-4, -0x1.2880736c8762dp-4,
+ 0x1.fc1ecf913961ap-5
+ };
+ f = v
+ * ((c[0] + v * c[1])
+ + v2 * ((c[2] + v * c[3]) + v2 * (c[4] + v * c[5] + v2 * c[6])));
+ f += l - tl[0];
+ double el = e * 0x1.34413509f79ffp-2;
+ r = el + f;
+ ub = r;
+ }
+ return ub;
+}
+libm_alias_float (__log10p1, log10p1)
projects / thirdparty / glibc.git / commitdiff
