xref: /openbsd-src/gnu/llvm/compiler-rt/lib/builtins/multc3.c (revision 3cab2bb3f667058bece8e38b12449a63a9d73c4b)
1*3cab2bb3Spatrick //===-- multc3.c - Implement __multc3 -------------------------------------===//
2*3cab2bb3Spatrick //
3*3cab2bb3Spatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*3cab2bb3Spatrick // See https://llvm.org/LICENSE.txt for license information.
5*3cab2bb3Spatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*3cab2bb3Spatrick //
7*3cab2bb3Spatrick //===----------------------------------------------------------------------===//
8*3cab2bb3Spatrick //
9*3cab2bb3Spatrick // This file implements __multc3 for the compiler_rt library.
10*3cab2bb3Spatrick //
11*3cab2bb3Spatrick //===----------------------------------------------------------------------===//
12*3cab2bb3Spatrick 
13*3cab2bb3Spatrick #include "int_lib.h"
14*3cab2bb3Spatrick #include "int_math.h"
15*3cab2bb3Spatrick 
16*3cab2bb3Spatrick // Returns: the product of a + ib and c + id
17*3cab2bb3Spatrick 
__multc3(long double a,long double b,long double c,long double d)18*3cab2bb3Spatrick COMPILER_RT_ABI long double _Complex __multc3(long double a, long double b,
19*3cab2bb3Spatrick                                               long double c, long double d) {
20*3cab2bb3Spatrick   long double ac = a * c;
21*3cab2bb3Spatrick   long double bd = b * d;
22*3cab2bb3Spatrick   long double ad = a * d;
23*3cab2bb3Spatrick   long double bc = b * c;
24*3cab2bb3Spatrick   long double _Complex z;
25*3cab2bb3Spatrick   __real__ z = ac - bd;
26*3cab2bb3Spatrick   __imag__ z = ad + bc;
27*3cab2bb3Spatrick   if (crt_isnan(__real__ z) && crt_isnan(__imag__ z)) {
28*3cab2bb3Spatrick     int recalc = 0;
29*3cab2bb3Spatrick     if (crt_isinf(a) || crt_isinf(b)) {
30*3cab2bb3Spatrick       a = crt_copysignl(crt_isinf(a) ? 1 : 0, a);
31*3cab2bb3Spatrick       b = crt_copysignl(crt_isinf(b) ? 1 : 0, b);
32*3cab2bb3Spatrick       if (crt_isnan(c))
33*3cab2bb3Spatrick         c = crt_copysignl(0, c);
34*3cab2bb3Spatrick       if (crt_isnan(d))
35*3cab2bb3Spatrick         d = crt_copysignl(0, d);
36*3cab2bb3Spatrick       recalc = 1;
37*3cab2bb3Spatrick     }
38*3cab2bb3Spatrick     if (crt_isinf(c) || crt_isinf(d)) {
39*3cab2bb3Spatrick       c = crt_copysignl(crt_isinf(c) ? 1 : 0, c);
40*3cab2bb3Spatrick       d = crt_copysignl(crt_isinf(d) ? 1 : 0, d);
41*3cab2bb3Spatrick       if (crt_isnan(a))
42*3cab2bb3Spatrick         a = crt_copysignl(0, a);
43*3cab2bb3Spatrick       if (crt_isnan(b))
44*3cab2bb3Spatrick         b = crt_copysignl(0, b);
45*3cab2bb3Spatrick       recalc = 1;
46*3cab2bb3Spatrick     }
47*3cab2bb3Spatrick     if (!recalc &&
48*3cab2bb3Spatrick         (crt_isinf(ac) || crt_isinf(bd) || crt_isinf(ad) || crt_isinf(bc))) {
49*3cab2bb3Spatrick       if (crt_isnan(a))
50*3cab2bb3Spatrick         a = crt_copysignl(0, a);
51*3cab2bb3Spatrick       if (crt_isnan(b))
52*3cab2bb3Spatrick         b = crt_copysignl(0, b);
53*3cab2bb3Spatrick       if (crt_isnan(c))
54*3cab2bb3Spatrick         c = crt_copysignl(0, c);
55*3cab2bb3Spatrick       if (crt_isnan(d))
56*3cab2bb3Spatrick         d = crt_copysignl(0, d);
57*3cab2bb3Spatrick       recalc = 1;
58*3cab2bb3Spatrick     }
59*3cab2bb3Spatrick     if (recalc) {
60*3cab2bb3Spatrick       __real__ z = CRT_INFINITY * (a * c - b * d);
61*3cab2bb3Spatrick       __imag__ z = CRT_INFINITY * (a * d + b * c);
62*3cab2bb3Spatrick     }
63*3cab2bb3Spatrick   }
64*3cab2bb3Spatrick   return z;
65*3cab2bb3Spatrick }
66