divxc3.c revision 2d1fdb26e458c4ddc04155c1d421bced3ba90cd0 
1/* ===-- divxc3.c - Implement __divxc3 -------------------------------------===
2 *
3 *                     The LLVM Compiler Infrastructure
4 *
5 * This file is dual licensed under the MIT and the University of Illinois Open
6 * Source Licenses. See LICENSE.TXT for details.
7 *
8 * ===----------------------------------------------------------------------===
9 *
10 * This file implements __divxc3 for the compiler_rt library.
11 *
12 */
13
14#if !_ARCH_PPC
15
16#include "int_lib.h"
17#include "int_math.h"
18
19/* Returns: the quotient of (a + ib) / (c + id) */
20
21COMPILER_RT_ABI long double _Complex
22__divxc3(long double __a, long double __b, long double __c, long double __d)
23{
24    int __ilogbw = 0;
25    long double __logbw = crt_logbl(crt_fmaxl(crt_fabsl(__c), crt_fabsl(__d)));
26    if (crt_isfinite(__logbw))
27    {
28        __ilogbw = (int)__logbw;
29        __c = crt_scalbnl(__c, -__ilogbw);
30        __d = crt_scalbnl(__d, -__ilogbw);
31    }
32    long double __denom = __c * __c + __d * __d;
33    long double _Complex z;
34    __real__ z = crt_scalbnl((__a * __c + __b * __d) / __denom, -__ilogbw);
35    __imag__ z = crt_scalbnl((__b * __c - __a * __d) / __denom, -__ilogbw);
36    if (crt_isnan(__real__ z) && crt_isnan(__imag__ z))
37    {
38        if ((__denom == 0) && (!crt_isnan(__a) || !crt_isnan(__b)))
39        {
40            __real__ z = crt_copysignl(CRT_INFINITY, __c) * __a;
41            __imag__ z = crt_copysignl(CRT_INFINITY, __c) * __b;
42        }
43        else if ((crt_isinf(__a) || crt_isinf(__b)) &&
44                 crt_isfinite(__c) && crt_isfinite(__d))
45        {
46            __a = crt_copysignl(crt_isinf(__a) ? 1 : 0, __a);
47            __b = crt_copysignl(crt_isinf(__b) ? 1 : 0, __b);
48            __real__ z = CRT_INFINITY * (__a * __c + __b * __d);
49            __imag__ z = CRT_INFINITY * (__b * __c - __a * __d);
50        }
51        else if (crt_isinf(__logbw) && __logbw > 0 &&
52                 crt_isfinite(__a) && crt_isfinite(__b))
53        {
54            __c = crt_copysignl(crt_isinf(__c) ? 1 : 0, __c);
55            __d = crt_copysignl(crt_isinf(__d) ? 1 : 0, __d);
56            __real__ z = 0 * (__a * __c + __b * __d);
57            __imag__ z = 0 * (__b * __c - __a * __d);
58        }
59    }
60    return z;
61}
62
63#endif
64