diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128/s_fromfpl_main.c')
-rw-r--r-- | sysdeps/ieee754/ldbl-128/s_fromfpl_main.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128/s_fromfpl_main.c b/sysdeps/ieee754/ldbl-128/s_fromfpl_main.c new file mode 100644 index 0000000000..cfff2c697f --- /dev/null +++ b/sysdeps/ieee754/ldbl-128/s_fromfpl_main.c @@ -0,0 +1,90 @@ +/* Round to integer type. ldbl-128 version. + Copyright (C) 2016 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/>. */ + +#include <errno.h> +#include <fenv.h> +#include <math.h> +#include <math_private.h> +#include <stdbool.h> +#include <stdint.h> + +#define BIAS 0x3fff +#define MANT_DIG 113 + +#if UNSIGNED +# define RET_TYPE uintmax_t +#else +# define RET_TYPE intmax_t +#endif + +#include <fromfp.h> + +RET_TYPE +FUNC (_Float128 x, int round, unsigned int width) +{ + if (width > INTMAX_WIDTH) + width = INTMAX_WIDTH; + uint64_t hx, lx; + GET_LDOUBLE_WORDS64 (hx, lx, x); + bool negative = (hx & 0x8000000000000000ULL) != 0; + if (width == 0) + return fromfp_domain_error (negative, width); + hx &= 0x7fffffffffffffffULL; + if ((hx | lx) == 0) + return 0; + int exponent = hx >> (MANT_DIG - 1 - 64); + exponent -= BIAS; + int max_exponent = fromfp_max_exponent (negative, width); + if (exponent > max_exponent) + return fromfp_domain_error (negative, width); + + hx &= ((1ULL << (MANT_DIG - 1 - 64)) - 1); + hx |= 1ULL << (MANT_DIG - 1 - 64); + uintmax_t uret; + bool half_bit, more_bits; + /* The exponent is at most 63, so we are shifting right by at least + 49 bits. */ + if (exponent >= -1) + { + int shift = MANT_DIG - 1 - exponent; + if (shift <= 64) + { + uint64_t h = 1ULL << (shift - 1); + half_bit = (lx & h) != 0; + more_bits = (lx & (h - 1)) != 0; + uret = hx << (64 - shift); + if (shift != 64) + uret |= lx >> shift; + } + else + { + uint64_t h = 1ULL << (shift - 1 - 64); + half_bit = (hx & h) != 0; + more_bits = ((hx & (h - 1)) | lx) != 0; + uret = hx >> (shift - 64); + } + } + else + { + uret = 0; + half_bit = false; + more_bits = true; + } + return fromfp_round_and_return (negative, uret, half_bit, more_bits, round, + exponent, max_exponent, width); +} |