1 //===-- fixxfti.c - Implement __fixxfti -----------------------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file implements __fixxfti for the compiler_rt library.
11 //===----------------------------------------------------------------------===//
17 // Returns: convert a to a signed long long, rounding toward zero.
19 // Assumption: long double is an intel 80 bit floating point type padded with 6
20 // bytes ti_int is a 128 bit integral type value in long double is representable
23 // gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee
24 // eeee | 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm
27 COMPILER_RT_ABI ti_int __fixxfti(long double a) {
28 const ti_int ti_max = (ti_int)((~(tu_int)0) / 2);
29 const ti_int ti_min = -ti_max - 1;
32 int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
35 ti_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15);
36 ti_int r = fb.u.low.all;
37 if ((unsigned)e >= sizeof(ti_int) * CHAR_BIT)
38 return a > 0 ? ti_max : ti_min;
46 #endif // CRT_HAS_128BIT