1 /* ===-- muldc3.c - Implement __muldc3 -------------------------------------===
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 __muldc3 for the compiler_rt library.
11  *
12  * ===----------------------------------------------------------------------===
13  */
14 
15 #include "int_lib.h"
16 #include "int_math.h"
17 
18 /* Returns: the product of a + ib and c + id */
19 
20 COMPILER_RT_ABI double _Complex
__muldc3(double __a,double __b,double __c,double __d)21 __muldc3(double __a, double __b, double __c, double __d)
22 {
23     double __ac = __a * __c;
24     double __bd = __b * __d;
25     double __ad = __a * __d;
26     double __bc = __b * __c;
27     double _Complex z;
28     __real__ z = __ac - __bd;
29     __imag__ z = __ad + __bc;
30     if (crt_isnan(__real__ z) && crt_isnan(__imag__ z))
31     {
32         int __recalc = 0;
33         if (crt_isinf(__a) || crt_isinf(__b))
34         {
35             __a = crt_copysign(crt_isinf(__a) ? 1 : 0, __a);
36             __b = crt_copysign(crt_isinf(__b) ? 1 : 0, __b);
37             if (crt_isnan(__c))
38                 __c = crt_copysign(0, __c);
39             if (crt_isnan(__d))
40                 __d = crt_copysign(0, __d);
41             __recalc = 1;
42         }
43         if (crt_isinf(__c) || crt_isinf(__d))
44         {
45             __c = crt_copysign(crt_isinf(__c) ? 1 : 0, __c);
46             __d = crt_copysign(crt_isinf(__d) ? 1 : 0, __d);
47             if (crt_isnan(__a))
48                 __a = crt_copysign(0, __a);
49             if (crt_isnan(__b))
50                 __b = crt_copysign(0, __b);
51             __recalc = 1;
52         }
53         if (!__recalc && (crt_isinf(__ac) || crt_isinf(__bd) ||
54                           crt_isinf(__ad) || crt_isinf(__bc)))
55         {
56             if (crt_isnan(__a))
57                 __a = crt_copysign(0, __a);
58             if (crt_isnan(__b))
59                 __b = crt_copysign(0, __b);
60             if (crt_isnan(__c))
61                 __c = crt_copysign(0, __c);
62             if (crt_isnan(__d))
63                 __d = crt_copysign(0, __d);
64             __recalc = 1;
65         }
66         if (__recalc)
67         {
68             __real__ z = CRT_INFINITY * (__a * __c - __b * __d);
69             __imag__ z = CRT_INFINITY * (__a * __d + __b * __c);
70         }
71     }
72     return z;
73 }
74