llvm-project

1
//===-- muldc3.c - Implement __muldc3 -------------------------------------===//
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 __muldc3 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

18
COMPILER_RT_ABI Dcomplex __muldc3(double __a, double __b, double __c,
19
                                  double __d) {
20
  double __ac = __a * __c;
21
  double __bd = __b * __d;
22
  double __ad = __a * __d;
23
  double __bc = __b * __c;
24
  Dcomplex z;
25
  COMPLEX_REAL(z) = __ac - __bd;
26
  COMPLEX_IMAGINARY(z) = __ad + __bc;
27
  if (crt_isnan(COMPLEX_REAL(z)) && crt_isnan(COMPLEX_IMAGINARY(z))) {
28
    int __recalc = 0;
29
    if (crt_isinf(__a) || crt_isinf(__b)) {
30
      __a = crt_copysign(crt_isinf(__a) ? 1 : 0, __a);
31
      __b = crt_copysign(crt_isinf(__b) ? 1 : 0, __b);
32
      if (crt_isnan(__c))
33
        __c = crt_copysign(0, __c);
34
      if (crt_isnan(__d))
35
        __d = crt_copysign(0, __d);
36
      __recalc = 1;
37
    }
38
    if (crt_isinf(__c) || crt_isinf(__d)) {
39
      __c = crt_copysign(crt_isinf(__c) ? 1 : 0, __c);
40
      __d = crt_copysign(crt_isinf(__d) ? 1 : 0, __d);
41
      if (crt_isnan(__a))
42
        __a = crt_copysign(0, __a);
43
      if (crt_isnan(__b))
44
        __b = crt_copysign(0, __b);
45
      __recalc = 1;
46
    }
47
    if (!__recalc && (crt_isinf(__ac) || crt_isinf(__bd) || crt_isinf(__ad) ||
48
                      crt_isinf(__bc))) {
49
      if (crt_isnan(__a))
50
        __a = crt_copysign(0, __a);
51
      if (crt_isnan(__b))
52
        __b = crt_copysign(0, __b);
53
      if (crt_isnan(__c))
54
        __c = crt_copysign(0, __c);
55
      if (crt_isnan(__d))
56
        __d = crt_copysign(0, __d);
57
      __recalc = 1;
58
    }
59
    if (__recalc) {
60
      COMPLEX_REAL(z) = CRT_INFINITY * (__a * __c - __b * __d);
61
      COMPLEX_IMAGINARY(z) = CRT_INFINITY * (__a * __d + __b * __c);
62
    }
63
  }
64
  return z;
65
}
66