freebsd-dev/contrib/compiler-rt/lib/builtins/fixunsxfdi.c
Dimitry Andric 25e141edd2 Pull in r231965 from upstream compiler-rt trunk (by Jörg Sonnenberger):
Refactor float to integer conversion to share the same code.
  80bit Intel/PPC long double is excluded due to lacking support
  for the abstraction. Consistently provide saturation logic.
  Extend to long double on 128bit IEEE extended platforms.

  Initial patch with test cases from GuanHong Liu.
  Reviewed by Steve Canon.

  Differential Revision: http://reviews.llvm.org/D2804

Pull in r232107 from upstream compiler-rt trunk (by Ed Maste):

  Use signed int implementation for __fixint

Requested by:	emaste
2015-03-14 12:40:19 +00:00

47 lines
1.4 KiB
C

/* ===-- fixunsxfdi.c - Implement __fixunsxfdi -----------------------------===
*
* 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 __fixunsxfdi for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#if !_ARCH_PPC
#include "int_lib.h"
/* 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
* du_int is a 64 bit integral type
* value in long double is representable in du_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
*/
COMPILER_RT_ABI du_int
__fixunsxfdi(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(du_int) * CHAR_BIT)
return ~(du_int)0;
return fb.u.low.all >> (63 - e);
}
#endif