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/* ===-- fixxfti.c - Implement __fixxfti -----------------------------------===
*
* 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 __fixxfti for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
#ifdef CRT_HAS_128BIT
/* Returns: convert a to a signed long long, rounding toward zero. */
/* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
* ti_int is a 128 bit integral type
* value in long double is representable in ti_int
*/
/* 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 ti_int
__fixxfti(long double a)
{
const ti_int ti_max = (ti_int)((~(tu_int)0) / 2);
const ti_int ti_min = -ti_max - 1;
long_double_bits fb;
fb.f = a;
int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
if (e < 0)
return 0;
ti_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15);
ti_int r = fb.u.low.all;
if ((unsigned)e >= sizeof(ti_int) * CHAR_BIT)
return a > 0 ? ti_max : ti_min;
if (e > 63)
r <<= (e - 63);
else
r >>= (63 - e);
return (r ^ s) - s;
}
#endif /* CRT_HAS_128BIT */
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