1*0b57cec5SDimitry Andric //===-- fixxfti.c - Implement __fixxfti -----------------------------------===// 2*0b57cec5SDimitry Andric // 3*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*0b57cec5SDimitry Andric // 7*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 8*0b57cec5SDimitry Andric // 9*0b57cec5SDimitry Andric // This file implements __fixxfti for the compiler_rt library. 10*0b57cec5SDimitry Andric // 11*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 12*0b57cec5SDimitry Andric 13*0b57cec5SDimitry Andric #include "int_lib.h" 14*0b57cec5SDimitry Andric 15*0b57cec5SDimitry Andric #ifdef CRT_HAS_128BIT 16*0b57cec5SDimitry Andric 17*0b57cec5SDimitry Andric // Returns: convert a to a signed long long, rounding toward zero. 18*0b57cec5SDimitry Andric 19*0b57cec5SDimitry Andric // Assumption: long double is an intel 80 bit floating point type padded with 6 20*0b57cec5SDimitry Andric // bytes ti_int is a 128 bit integral type value in long double is representable 21*0b57cec5SDimitry Andric // in ti_int 22*0b57cec5SDimitry Andric 23*0b57cec5SDimitry Andric // gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee 24*0b57cec5SDimitry Andric // eeee | 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm 25*0b57cec5SDimitry Andric // mmmm mmmm mmmm 26*0b57cec5SDimitry Andric 27*0b57cec5SDimitry Andric COMPILER_RT_ABI ti_int __fixxfti(long double a) { 28*0b57cec5SDimitry Andric const ti_int ti_max = (ti_int)((~(tu_int)0) / 2); 29*0b57cec5SDimitry Andric const ti_int ti_min = -ti_max - 1; 30*0b57cec5SDimitry Andric long_double_bits fb; 31*0b57cec5SDimitry Andric fb.f = a; 32*0b57cec5SDimitry Andric int e = (fb.u.high.s.low & 0x00007FFF) - 16383; 33*0b57cec5SDimitry Andric if (e < 0) 34*0b57cec5SDimitry Andric return 0; 35*0b57cec5SDimitry Andric ti_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15); 36*0b57cec5SDimitry Andric ti_int r = fb.u.low.all; 37*0b57cec5SDimitry Andric if ((unsigned)e >= sizeof(ti_int) * CHAR_BIT) 38*0b57cec5SDimitry Andric return a > 0 ? ti_max : ti_min; 39*0b57cec5SDimitry Andric if (e > 63) 40*0b57cec5SDimitry Andric r <<= (e - 63); 41*0b57cec5SDimitry Andric else 42*0b57cec5SDimitry Andric r >>= (63 - e); 43*0b57cec5SDimitry Andric return (r ^ s) - s; 44*0b57cec5SDimitry Andric } 45*0b57cec5SDimitry Andric 46*0b57cec5SDimitry Andric #endif // CRT_HAS_128BIT 47