1 //===-- fixunsxfsi.c - Implement __fixunsxfsi -----------------------------===//
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 __fixunsxfsi for the compiler_rt library.
11 //===----------------------------------------------------------------------===//
17 // Returns: convert a to a unsigned int, rounding toward zero.
18 // Negative values all become zero.
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
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
28 #if defined(_MSC_VER) && !defined(__clang__)
29 // MSVC throws a warning about 'unitialized variable use' here,
30 // disable it for builds that warn-as-error
32 #pragma warning(disable : 4700)
35 COMPILER_RT_ABI su_int __fixunsxfsi(long double a) {
38 int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
39 if (e < 0 || (fb.u.high.s.low & 0x00008000))
41 if ((unsigned)e > sizeof(su_int) * CHAR_BIT)
43 return fb.u.low.s.high >> (31 - e);
46 #if defined(_MSC_VER) && !defined(__clang__)