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