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/* ===-- floatdixf.c - Implement __floatdixf -------------------------------===
*
* 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 __floatdixf 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
* di_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
*/
COMPILER_RT_ABI long double
__floatdixf(di_int a)
{
if (a == 0)
return 0.0;
const unsigned N = sizeof(di_int) * CHAR_BIT;
const di_int s = a >> (N-1);
a = (a ^ s) - s;
int clz = __builtin_clzll(a);
int e = (N - 1) - clz ; /* exponent */
long_double_bits fb;
fb.u.high.s.low = ((su_int)s & 0x00008000) | /* sign */
(e + 16383); /* exponent */
fb.u.low.all = a << clz; /* mantissa */
return fb.f;
}
#endif /* !_ARCH_PPC */
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