1 /* Round a double value to a long long in the current rounding mode. 2 Copyright (C) 1997-2021 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <https://www.gnu.org/licenses/>. */ 18 19 #include <limits.h> 20 #include <math.h> 21 #include <math_ldbl_opt.h> 22 #include <math_private.h> 23 #include <stdint.h> 24 #include <libm-alias-double.h> 25 26 long long int __llrint(double x)27__llrint (double x) 28 { 29 #ifdef _ARCH_PWR4 30 /* Assume powerpc64 instructions availability. */ 31 long long int ret; 32 __asm__ ("fctid %0, %1" : "=d" (ret) : "d" (x)); 33 return ret; 34 #else 35 double rx = rint (x); 36 if (HAVE_PPC_FCTIDZ || rx != x) 37 return (long long int) rx; 38 else 39 { 40 /* Avoid incorrect exceptions from libgcc conversions (as of GCC 41 5): <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412>. */ 42 if (fabs (rx) < 0x1p31) 43 return (long long int) (long int) rx; 44 uint64_t i0; 45 EXTRACT_WORDS64 (i0, rx); 46 int exponent = ((i0 >> 52) & 0x7ff) - 0x3ff; 47 if (exponent < 63) 48 { 49 unsigned long long int mant 50 = (i0 & ((1ULL << 52) - 1)) | (1ULL << 52); 51 if (exponent < 52) 52 mant >>= 52 - exponent; 53 else 54 mant <<= exponent - 52; 55 return (long long int) ((i0 & (1ULL << 63)) != 0 ? -mant : mant); 56 } 57 else if (rx == (double) LLONG_MIN) 58 return LLONG_MIN; 59 else 60 return (long long int) (long int) rx << 32; 61 } 62 #endif 63 } 64 #ifndef __llrint 65 libm_alias_double (__llrint, llrint) 66 #endif 67