1 //===-- fixunsxfsi.c - Implement __fixunsxfsi -----------------------------===// 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 __fixunsxfsi 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 unsigned int, rounding toward zero. 18 // Negative values all become zero. 19 20 // Assumption: long double is an intel 80 bit floating point type padded with 6 21 // bytes su_int is a 32 bit integral type value in long double is representable 22 // in su_int or is negative 23 24 // gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee 25 // eeee | 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm 26 // mmmm mmmm mmmm 27 28 #if defined(_MSC_VER) && !defined(__clang__) 29 // MSVC throws a warning about 'uninitialized variable use' here, 30 // disable it for builds that warn-as-error 31 #pragma warning(push) 32 #pragma warning(disable : 4700) 33 #endif 34 35 COMPILER_RT_ABI su_int __fixunsxfsi(long double a) { 36 long_double_bits fb; 37 fb.f = a; 38 int e = (fb.u.high.s.low & 0x00007FFF) - 16383; 39 if (e < 0 || (fb.u.high.s.low & 0x00008000)) 40 return 0; 41 if ((unsigned)e > sizeof(su_int) * CHAR_BIT) 42 return ~(su_int)0; 43 return fb.u.low.s.high >> (31 - e); 44 } 45 46 #if defined(_MSC_VER) && !defined(__clang__) 47 #pragma warning(pop) 48 #endif 49 50 #endif // !_ARCH_PPC 51