xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/fixunsxfdi.c (revision 5f757f3ff9144b609b3c433dfd370cc6bdc191ad)
10b57cec5SDimitry Andric //===-- fixunsxfdi.c - Implement __fixunsxfdi -----------------------------===//
20b57cec5SDimitry Andric //
30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
60b57cec5SDimitry Andric //
70b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
80b57cec5SDimitry Andric //
90b57cec5SDimitry Andric // This file implements __fixunsxfdi for the compiler_rt library.
100b57cec5SDimitry Andric //
110b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
120b57cec5SDimitry Andric 
130b57cec5SDimitry Andric #if !_ARCH_PPC
140b57cec5SDimitry Andric 
150b57cec5SDimitry Andric #include "int_lib.h"
160b57cec5SDimitry Andric 
170b57cec5SDimitry Andric // Returns: convert a to a unsigned long long, rounding toward zero.
180b57cec5SDimitry Andric //          Negative values all become zero.
190b57cec5SDimitry Andric 
200b57cec5SDimitry Andric // Assumption: long double is an intel 80 bit floating point type padded with 6
210b57cec5SDimitry Andric // bytes du_int is a 64 bit integral type value in long double is representable
220b57cec5SDimitry Andric // in du_int or is negative (no range checking performed)
230b57cec5SDimitry Andric 
240b57cec5SDimitry Andric // gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee
250b57cec5SDimitry Andric // eeee | 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm
260b57cec5SDimitry Andric // mmmm mmmm mmmm
270b57cec5SDimitry Andric 
2868d75effSDimitry Andric #if defined(_MSC_VER) && !defined(__clang__)
29349cc55cSDimitry Andric // MSVC throws a warning about 'uninitialized variable use' here,
3068d75effSDimitry Andric // disable it for builds that warn-as-error
3168d75effSDimitry Andric #pragma warning(push)
3268d75effSDimitry Andric #pragma warning(disable : 4700)
3368d75effSDimitry Andric #endif
3468d75effSDimitry Andric 
35*5f757f3fSDimitry Andric COMPILER_RT_ABI du_int __fixunsxfdi(xf_float a) {
36*5f757f3fSDimitry Andric   xf_bits fb;
370b57cec5SDimitry Andric   fb.f = a;
380b57cec5SDimitry Andric   int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
390b57cec5SDimitry Andric   if (e < 0 || (fb.u.high.s.low & 0x00008000))
400b57cec5SDimitry Andric     return 0;
410b57cec5SDimitry Andric   if ((unsigned)e > sizeof(du_int) * CHAR_BIT)
420b57cec5SDimitry Andric     return ~(du_int)0;
430b57cec5SDimitry Andric   return fb.u.low.all >> (63 - e);
440b57cec5SDimitry Andric }
450b57cec5SDimitry Andric 
4668d75effSDimitry Andric #if defined(_MSC_VER) && !defined(__clang__)
4768d75effSDimitry Andric #pragma warning(pop)
480b57cec5SDimitry Andric #endif
4968d75effSDimitry Andric 
5068d75effSDimitry Andric #endif //!_ARCH_PPC
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