forked from OSchip/llvm-project
46 lines
1.3 KiB
C
46 lines
1.3 KiB
C
/* ===-- fixdfti.c - Implement __fixdfti -----------------------------------===
|
|
*
|
|
* 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 __fixdfti for the compiler_rt library.
|
|
*
|
|
* ===----------------------------------------------------------------------===
|
|
*/
|
|
|
|
#include "int_lib.h"
|
|
|
|
#if __x86_64
|
|
|
|
/* Returns: convert a to a signed long long, rounding toward zero. */
|
|
|
|
/* Assumption: double is a IEEE 64 bit floating point type
|
|
* su_int is a 32 bit integral type
|
|
* value in double is representable in ti_int (no range checking performed)
|
|
*/
|
|
|
|
/* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */
|
|
|
|
ti_int
|
|
__fixdfti(double a)
|
|
{
|
|
double_bits fb;
|
|
fb.f = a;
|
|
int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023;
|
|
if (e < 0)
|
|
return 0;
|
|
ti_int s = (si_int)(fb.u.s.high & 0x80000000) >> 31;
|
|
ti_int r = 0x0010000000000000uLL | (0x000FFFFFFFFFFFFFuLL & fb.u.all);
|
|
if (e > 52)
|
|
r <<= (e - 52);
|
|
else
|
|
r >>= (52 - e);
|
|
return (r ^ s) - s;
|
|
}
|
|
|
|
#endif
|