freebsd-skq/contrib/compiler-rt/lib/floatundixf.c
Ed Schouten ef8821e5db Upgrade libcompiler_rt from revision 117047 to 132478.
It seems there have only been a small amount to the compiler-rt source
code in the mean time. I'd rather have the code in sync as much as
possible by the time we release 9.0. Changes:

- The libcompiler_rt library is now dual licensed under both the
  University of Illinois "BSD-Like" license and the MIT license.

- Our local modifications for using .hidden instead of .private_extern
  have been upstreamed, meaning our changes to lib/assembly.h can now be
  reverted.

- A possible endless recursion in __modsi3() has been fixed.

- Support for ARM EABI has been added, but it has no effect on FreeBSD
  (yet).

- The functions __udivmodsi4 and __divmodsi4 have been added.

Requested by:	many, including bf@ and Pedro Giffuni
2011-06-03 17:49:16 +00:00

43 lines
1.3 KiB
C

/* ===-- floatundixf.c - Implement __floatundixf ---------------------------===
*
* 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 __floatundixf for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#if !_ARCH_PPC
#include "int_lib.h"
/* Returns: convert a to a long double, rounding toward even. */
/* Assumption: long double is a IEEE 80 bit floating point type padded to 128 bits
* du_int is a 64 bit integral type
*/
/* 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
*/
long double
__floatundixf(du_int a)
{
if (a == 0)
return 0.0;
const unsigned N = sizeof(du_int) * CHAR_BIT;
int clz = __builtin_clzll(a);
int e = (N - 1) - clz ; /* exponent */
long_double_bits fb;
fb.u.high.s.low = (e + 16383); /* exponent */
fb.u.low.all = a << clz; /* mantissa */
return fb.f;
}
#endif /* _ARCH_PPC */