forked from OSchip/llvm-project
50 lines
1.4 KiB
C
50 lines
1.4 KiB
C
/* ===-- fixunsxfti.c - Implement __fixunsxfti -----------------------------===
|
|
*
|
|
* 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 __fixunsxfti for the compiler_rt library.
|
|
*
|
|
* ===----------------------------------------------------------------------===
|
|
*/
|
|
|
|
#include "int_lib.h"
|
|
|
|
#if __x86_64
|
|
|
|
/* Returns: convert a to a unsigned long long, rounding toward zero.
|
|
* Negative values all become zero.
|
|
*/
|
|
|
|
/* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
|
|
* tu_int is a 64 bit integral type
|
|
* value in long double is representable in tu_int or is negative
|
|
* (no range checking performed)
|
|
*/
|
|
|
|
/* 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
|
|
*/
|
|
|
|
tu_int
|
|
__fixunsxfti(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;
|
|
tu_int r = fb.u.low.all;
|
|
if (e > 63)
|
|
r <<= (e - 63);
|
|
else
|
|
r >>= (63 - e);
|
|
return r;
|
|
}
|
|
|
|
#endif
|