diff options
Diffstat (limited to 'sysdeps/powerpc/fpu')
| -rw-r--r-- | sysdeps/powerpc/fpu/s_logb.c | 64 | ||||
| -rw-r--r-- | sysdeps/powerpc/fpu/s_logbf.c | 56 | ||||
| -rw-r--r-- | sysdeps/powerpc/fpu/s_logbl.c | 78 |
3 files changed, 198 insertions, 0 deletions
diff --git a/sysdeps/powerpc/fpu/s_logb.c b/sysdeps/powerpc/fpu/s_logb.c new file mode 100644 index 0000000..364f7f0 --- /dev/null +++ b/sysdeps/powerpc/fpu/s_logb.c @@ -0,0 +1,64 @@ +/* Get exponent of a floating-point value. PowerPC version. + Copyright (C) 2012-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* ISA 2.07 provides fast GPR to FP instruction (mfvsr{d,wz}) which make + generic implementation faster. */ +#if defined(_ARCH_PWR8) || !defined(_ARCH_PWR7) +# include <sysdeps/ieee754/dbl-64/s_logb.c> +#else +# include <math.h> +# include <math_private.h> +# include <math_ldbl_opt.h> +# include <libm-alias-double.h> + +/* This implementation avoids FP to INT conversions by using VSX + bitwise instructions over FP values. */ +double +__logb (double x) +{ + double ret; + + if (__glibc_unlikely (x == 0.0)) + /* Raise FE_DIVBYZERO and return -HUGE_VAL[LF]. */ + return -1.0 / fabs (x); + + /* Mask to extract the exponent. */ + asm ("xxland %x0,%x1,%x2\n" + "fcfid %0,%0" + : "=d" (ret) + : "d" (x), "d" (0x7ff0000000000000ULL)); + ret = (ret * 0x1p-52) - 1023.0; + if (ret > 1023.0) + /* Multiplication is used to set logb (+-INF) = INF. */ + return (x * x); + else if (ret == -1023.0) + { + /* POSIX specifies that denormal numbers are treated as + though they were normalized. */ + int64_t ix; + EXTRACT_WORDS64 (ix, x); + ix &= UINT64_C (0x7fffffffffffffff); + return (double) (-1023 - (__builtin_clzll (ix) - 12)); + } + /* Test to avoid logb_downward (0.0) == -0.0. */ + return ret == -0.0 ? 0.0 : ret; +} +# ifndef __logb +libm_alias_double (__logb, logb) +# endif +#endif diff --git a/sysdeps/powerpc/fpu/s_logbf.c b/sysdeps/powerpc/fpu/s_logbf.c new file mode 100644 index 0000000..cf564ad --- /dev/null +++ b/sysdeps/powerpc/fpu/s_logbf.c @@ -0,0 +1,56 @@ +/* Get exponent of a floating-point value. PowerPC version. + Copyright (C) 2012-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* ISA 2.07 provides fast GPR to FP instruction (mfvsr{d,wz}) which make + generic implementation faster. */ +#if defined(_ARCH_PWR8) || !defined(_ARCH_PWR7) +# include <sysdeps/ieee754/flt-32/s_logbf.c> +#else +# include <math.h> +# include <libm-alias-float.h> +/* This implementation avoids FP to INT conversions by using VSX + bitwise instructions over FP values. */ +float +__logbf (float x) +{ + /* VSX operation are all done internally as double. */ + double ret; + + if (__glibc_unlikely (x == 0.0)) + /* Raise FE_DIVBYZERO and return -HUGE_VAL[LF]. */ + return -1.0 / fabs (x); + + /* mask to extract the exponent. */ + asm ("xxland %x0,%x1,%x2\n" + "fcfid %0,%0" + : "=d"(ret) + : "d" (x), "d" (0x7ff0000000000000ULL)); + /* ret = (ret >> 52) - 1023.0, since ret is double. */ + ret = (ret * 0x1p-52) - 1023.0; + if (ret > 127.0) + /* Multiplication is used to set logb (+-INF) = INF. */ + return (x * x); + /* Since operations are done with double we don't need + additional tests for subnormal numbers. + The test is to avoid logb_downward (0.0) == -0.0. */ + return ret == -0.0 ? 0.0 : ret; +} +# ifndef __logbf +libm_alias_float (__logb, logb) +# endif +#endif diff --git a/sysdeps/powerpc/fpu/s_logbl.c b/sysdeps/powerpc/fpu/s_logbl.c new file mode 100644 index 0000000..543cd4a --- /dev/null +++ b/sysdeps/powerpc/fpu/s_logbl.c @@ -0,0 +1,78 @@ +/* Get exponent of a floating-point value. PowerPC version. + Copyright (C) 2012-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* ISA 2.07 provides fast GPR to FP instruction (mfvsr{d,wz}) which make + generic implementation faster. */ +#if defined(_ARCH_PWR8) || !defined(_ARCH_PWR7) +# include <./sysdeps/ieee754/ldbl-128ibm/s_logbl.c> +#else +# include <math.h> +# include <math_private.h> +# include <math_ldbl_opt.h> + +/* This implementation avoids FP to INT conversions by using VSX + bitwise instructions over FP values. */ +long double +__logbl (long double x) +{ + double xh, xl; + double ret; + int64_t hx; + + if (__glibc_unlikely (x == 0.0)) + /* Raise FE_DIVBYZERO and return -HUGE_VAL[LF]. */ + return -1.0L / __builtin_fabsl (x); + + ldbl_unpack (x, &xh, &xl); + EXTRACT_WORDS64 (hx, xh); + + /* Mask to extract the exponent. */ + asm ("xxland %x0,%x1,%x2\n" + "fcfid %0,%0" + : "=d" (ret) + : "d" (xh), "d" (0x7ff0000000000000ULL)); + ret = (ret * 0x1p-52) - 1023.0; + if (ret > 1023.0) + /* Multiplication is used to set logb (+-INF) = INF. */ + return (xh * xh); + else if (ret == -1023.0) + { + /* POSIX specifies that denormal number is treated as + though it were normalized. */ + return (long double) (- (__builtin_clzll (hx & 0x7fffffffffffffffLL) \ + - 12) - 1023); + } + else if ((hx & 0x000fffffffffffffLL) == 0) + { + /* If the high part is a power of 2, and the low part is nonzero + with the opposite sign, the low part affects the + exponent. */ + int64_t lx, rhx; + EXTRACT_WORDS64 (lx, xl); + rhx = (hx & 0x7ff0000000000000LL) >> 52; + if ((hx ^ lx) < 0 && (lx & 0x7fffffffffffffffLL) != 0) + rhx--; + return (long double) (rhx - 1023); + } + /* Test to avoid logb_downward (0.0) == -0.0. */ + return ret == -0.0 ? 0.0 : ret; +} +# ifndef __logbl +long_double_symbol (libm, __logbl, logbl); +# endif +#endif |