1//===-- fixxfdi.c - Implement __fixxfdi -----------------------------------===// 2// 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 6// 7//===----------------------------------------------------------------------===// 8// 9// This file implements __fixxfdi for the compiler_rt library. 10// 11//===----------------------------------------------------------------------===// 12 13#if !_ARCH_PPC 14 15#include "int_lib.h" 16 17// Returns: convert a to a signed long long, rounding toward zero. 18 19// Assumption: long double is an intel 80 bit floating point type padded with 6 20// bytes di_int is a 64 bit integral type value in long double is representable 21// in di_int (no range checking performed) 22 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 25// mmmm mmmm mmmm 26 27#if defined(_MSC_VER) && !defined(__clang__) 28// MSVC throws a warning about 'unitialized variable use' here, 29// disable it for builds that warn-as-error 30#pragma warning(push) 31#pragma warning(disable : 4700) 32#endif 33 34COMPILER_RT_ABI di_int __fixxfdi(long double a) { 35 const di_int di_max = (di_int)((~(du_int)0) / 2); 36 const di_int di_min = -di_max - 1; 37 long_double_bits fb; 38 fb.f = a; 39 int e = (fb.u.high.s.low & 0x00007FFF) - 16383; 40 if (e < 0) 41 return 0; 42 if ((unsigned)e >= sizeof(di_int) * CHAR_BIT) 43 return a > 0 ? di_max : di_min; 44 di_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15); 45 di_int r = fb.u.low.all; 46 r = (du_int)r >> (63 - e); 47 return (r ^ s) - s; 48} 49 50#if defined(_MSC_VER) && !defined(__clang__) 51#pragma warning(pop) 52#endif 53 54#endif // !_ARCH_PPC 55