cosmopolitan/third_party/compiler_rt/fixunsxfsi.c
Justine Tunney fa20edc44d
Reduce header complexity
- Remove most __ASSEMBLER__ __LINKER__ ifdefs
- Rename libc/intrin/bits.h to libc/serialize.h
- Block pthread cancelation in fchmodat() polyfill
- Remove `clang-format off` statements in third_party
2023-11-28 14:39:42 -08:00

51 lines
1.6 KiB
C

/* ===-- fixunsxfsi.c - Implement __fixunsxfsi -----------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* This file implements __fixunsxfsi for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "libc/math.h"
#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
__static_yoink("huge_compiler_rt_license");
#if !_ARCH_PPC
#include "third_party/compiler_rt/int_lib.h"
/* Returns: convert a to a unsigned int, rounding toward zero.
* Negative values all become zero.
*/
/* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
* su_int is a 32 bit integral type
* value in long double is representable in su_int or is negative
*/
/* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
* 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
*/
COMPILER_RT_ABI su_int
__fixunsxfsi(long double a)
{
long_double_bits fb;
fb.f = a;
int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
if (e < 0 || (fb.u.high.s.low & 0x00008000))
return 0;
if ((unsigned)e > sizeof(su_int) * CHAR_BIT)
return ~(su_int)0;
return fb.u.low.s.high >> (31 - e);
}
#endif /* !_ARCH_PPC */
#endif /* long double is long */