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
35COMPILER_RT_ABI su_int __fixunsxfsi(xf_float a) {
36 xf_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

source code of compiler-rt/lib/builtins/fixunsxfsi.c