1214152Sed/* ===-- floatundixf.c - Implement __floatundixf ---------------------------===
2214152Sed *
3214152Sed *                     The LLVM Compiler Infrastructure
4214152Sed *
5222656Sed * This file is dual licensed under the MIT and the University of Illinois Open
6222656Sed * Source Licenses. See LICENSE.TXT for details.
7214152Sed *
8214152Sed * ===----------------------------------------------------------------------===
9214152Sed *
10214152Sed * This file implements __floatundixf for the compiler_rt library.
11214152Sed *
12214152Sed * ===----------------------------------------------------------------------===
13214152Sed */
14214152Sed
15214152Sed#if !_ARCH_PPC
16214152Sed
17214152Sed#include "int_lib.h"
18214152Sed
19214152Sed/* Returns: convert a to a long double, rounding toward even. */
20214152Sed
21214152Sed/* Assumption: long double is a IEEE 80 bit floating point type padded to 128 bits
22214152Sed *             du_int is a 64 bit integral type
23214152Sed */
24214152Sed
25214152Sed/* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
26214152Sed * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
27214152Sed */
28214152Sedlong double
29214152Sed__floatundixf(du_int a)
30214152Sed{
31214152Sed    if (a == 0)
32214152Sed        return 0.0;
33214152Sed    const unsigned N = sizeof(du_int) * CHAR_BIT;
34214152Sed    int clz = __builtin_clzll(a);
35214152Sed    int e = (N - 1) - clz ;    /* exponent */
36214152Sed    long_double_bits fb;
37214152Sed    fb.u.high.s.low = (e + 16383);              /* exponent */
38214152Sed    fb.u.low.all = a << clz;                   /* mantissa */
39214152Sed    return fb.f;
40214152Sed}
41214152Sed
42214152Sed#endif /* _ARCH_PPC */
43