1// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
2// See https://llvm.org/LICENSE.txt for license information.
3// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
4
5#include "../int_math.h"
6#include "DD.h"
7// Use DOUBLE_PRECISION because the soft-fp method we use is logb (on the upper
8// half of the long doubles), even though this file defines complex division for
9// 128-bit floats.
10#define DOUBLE_PRECISION
11#include "../fp_lib.h"
12
13#if !defined(CRT_INFINITY) && defined(HUGE_VAL)
14#define CRT_INFINITY HUGE_VAL
15#endif // CRT_INFINITY
16
17#define makeFinite(x)                                                          \
18  {                                                                            \
19    (x).s.hi = crt_copysign(crt_isinf((x).s.hi) ? 1.0 : 0.0, (x).s.hi);        \
20    (x).s.lo = 0.0;                                                            \
21  }
22
23long double _Complex __divtc3(long double a, long double b, long double c,
24                              long double d) {
25  DD cDD = {.ld = c};
26  DD dDD = {.ld = d};
27
28  int ilogbw = 0;
29  const double logbw =
30      __compiler_rt_logb(__compiler_rt_fmax(crt_fabs(cDD.s.hi),
31                                            crt_fabs(dDD.s.hi)));
32
33  if (crt_isfinite(logbw)) {
34    ilogbw = (int)logbw;
35
36    cDD.s.hi = __compiler_rt_scalbn(cDD.s.hi, -ilogbw);
37    cDD.s.lo = __compiler_rt_scalbn(cDD.s.lo, -ilogbw);
38    dDD.s.hi = __compiler_rt_scalbn(dDD.s.hi, -ilogbw);
39    dDD.s.lo = __compiler_rt_scalbn(dDD.s.lo, -ilogbw);
40  }
41
42  const long double denom =
43      __gcc_qadd(__gcc_qmul(cDD.ld, cDD.ld), __gcc_qmul(dDD.ld, dDD.ld));
44  const long double realNumerator =
45      __gcc_qadd(__gcc_qmul(a, cDD.ld), __gcc_qmul(b, dDD.ld));
46  const long double imagNumerator =
47      __gcc_qsub(__gcc_qmul(b, cDD.ld), __gcc_qmul(a, dDD.ld));
48
49  DD real = {.ld = __gcc_qdiv(realNumerator, denom)};
50  DD imag = {.ld = __gcc_qdiv(imagNumerator, denom)};
51
52  real.s.hi = __compiler_rt_scalbn(real.s.hi, -ilogbw);
53  real.s.lo = __compiler_rt_scalbn(real.s.lo, -ilogbw);
54  imag.s.hi = __compiler_rt_scalbn(imag.s.hi, -ilogbw);
55  imag.s.lo = __compiler_rt_scalbn(imag.s.lo, -ilogbw);
56
57  if (crt_isnan(real.s.hi) && crt_isnan(imag.s.hi)) {
58    DD aDD = {.ld = a};
59    DD bDD = {.ld = b};
60    DD rDD = {.ld = denom};
61
62    if ((rDD.s.hi == 0.0) && (!crt_isnan(aDD.s.hi) || !crt_isnan(bDD.s.hi))) {
63      real.s.hi = crt_copysign(CRT_INFINITY, cDD.s.hi) * aDD.s.hi;
64      real.s.lo = 0.0;
65      imag.s.hi = crt_copysign(CRT_INFINITY, cDD.s.hi) * bDD.s.hi;
66      imag.s.lo = 0.0;
67    }
68
69    else if ((crt_isinf(aDD.s.hi) || crt_isinf(bDD.s.hi)) &&
70             crt_isfinite(cDD.s.hi) && crt_isfinite(dDD.s.hi)) {
71      makeFinite(aDD);
72      makeFinite(bDD);
73      real.s.hi = CRT_INFINITY * (aDD.s.hi * cDD.s.hi + bDD.s.hi * dDD.s.hi);
74      real.s.lo = 0.0;
75      imag.s.hi = CRT_INFINITY * (bDD.s.hi * cDD.s.hi - aDD.s.hi * dDD.s.hi);
76      imag.s.lo = 0.0;
77    }
78
79    else if ((crt_isinf(cDD.s.hi) || crt_isinf(dDD.s.hi)) &&
80             crt_isfinite(aDD.s.hi) && crt_isfinite(bDD.s.hi)) {
81      makeFinite(cDD);
82      makeFinite(dDD);
83      real.s.hi =
84          crt_copysign(0.0, (aDD.s.hi * cDD.s.hi + bDD.s.hi * dDD.s.hi));
85      real.s.lo = 0.0;
86      imag.s.hi =
87          crt_copysign(0.0, (bDD.s.hi * cDD.s.hi - aDD.s.hi * dDD.s.hi));
88      imag.s.lo = 0.0;
89    }
90  }
91
92  long double _Complex z;
93  __real__ z = real.ld;
94  __imag__ z = imag.ld;
95
96  return z;
97}
98