1 /* ===-- muldc3.c - Implement __muldc3 -------------------------------------===
3 * The LLVM Compiler Infrastructure
5 * This file is dual licensed under the MIT and the University of Illinois Open
6 * Source Licenses. See LICENSE.TXT for details.
8 * ===----------------------------------------------------------------------===
10 * This file implements __muldc3 for the compiler_rt library.
12 * ===----------------------------------------------------------------------===
18 /* Returns: the product of a + ib and c + id */
21 __muldc3(double __a, double __b, double __c, double __d)
23 double __ac = __a * __c;
24 double __bd = __b * __d;
25 double __ad = __a * __d;
26 double __bc = __b * __c;
28 __real__ z = __ac - __bd;
29 __imag__ z = __ad + __bc;
30 if (crt_isnan(__real__ z) && crt_isnan(__imag__ z))
33 if (crt_isinf(__a) || crt_isinf(__b))
35 __a = crt_copysign(crt_isinf(__a) ? 1 : 0, __a);
36 __b = crt_copysign(crt_isinf(__b) ? 1 : 0, __b);
38 __c = crt_copysign(0, __c);
40 __d = crt_copysign(0, __d);
43 if (crt_isinf(__c) || crt_isinf(__d))
45 __c = crt_copysign(crt_isinf(__c) ? 1 : 0, __c);
46 __d = crt_copysign(crt_isinf(__d) ? 1 : 0, __d);
48 __a = crt_copysign(0, __a);
50 __b = crt_copysign(0, __b);
53 if (!__recalc && (crt_isinf(__ac) || crt_isinf(__bd) ||
54 crt_isinf(__ad) || crt_isinf(__bc)))
57 __a = crt_copysign(0, __a);
59 __b = crt_copysign(0, __b);
61 __c = crt_copysign(0, __c);
63 __d = crt_copysign(0, __d);
68 __real__ z = CRT_INFINITY * (__a * __c - __b * __d);
69 __imag__ z = CRT_INFINITY * (__a * __d + __b * __c);