1/* This file is distributed under the University of Illinois Open Source
2 * License. See LICENSE.TXT for details.
3 */
4
5#include "DD.h"
6#include "../int_math.h"
7
8#if !defined(CRT_INFINITY) && defined(HUGE_VAL)
9#define CRT_INFINITY HUGE_VAL
10#endif /* CRT_INFINITY */
11
12#define makeFinite(x) { \
13    (x).s.hi = crt_copysign(crt_isinf((x).s.hi) ? 1.0 : 0.0, (x).s.hi); \
14    (x).s.lo = 0.0;                                                     \
15  }
16
17long double __gcc_qadd(long double, long double);
18long double __gcc_qsub(long double, long double);
19long double __gcc_qmul(long double, long double);
20long double __gcc_qdiv(long double, long double);
21
22long double _Complex
23__divtc3(long double a, long double b, long double c, long double d)
24{
25	DD cDD = { .ld = c };
26	DD dDD = { .ld = d };
27
28	int ilogbw = 0;
29	const double logbw = crt_logb(crt_fmax(crt_fabs(cDD.s.hi), crt_fabs(dDD.s.hi) ));
30
31	if (crt_isfinite(logbw))
32	{
33		ilogbw = (int)logbw;
34
35		cDD.s.hi = crt_scalbn(cDD.s.hi, -ilogbw);
36		cDD.s.lo = crt_scalbn(cDD.s.lo, -ilogbw);
37		dDD.s.hi = crt_scalbn(dDD.s.hi, -ilogbw);
38		dDD.s.lo = crt_scalbn(dDD.s.lo, -ilogbw);
39	}
40
41	const long double denom = __gcc_qadd(__gcc_qmul(cDD.ld, cDD.ld), __gcc_qmul(dDD.ld, dDD.ld));
42	const long double realNumerator = __gcc_qadd(__gcc_qmul(a,cDD.ld), __gcc_qmul(b,dDD.ld));
43	const long double imagNumerator = __gcc_qsub(__gcc_qmul(b,cDD.ld), __gcc_qmul(a,dDD.ld));
44
45	DD real = { .ld = __gcc_qdiv(realNumerator, denom) };
46	DD imag = { .ld = __gcc_qdiv(imagNumerator, denom) };
47
48	real.s.hi = crt_scalbn(real.s.hi, -ilogbw);
49	real.s.lo = crt_scalbn(real.s.lo, -ilogbw);
50	imag.s.hi = crt_scalbn(imag.s.hi, -ilogbw);
51	imag.s.lo = crt_scalbn(imag.s.lo, -ilogbw);
52
53	if (crt_isnan(real.s.hi) && crt_isnan(imag.s.hi))
54	{
55		DD aDD = { .ld = a };
56		DD bDD = { .ld = b };
57		DD rDD = { .ld = denom };
58
59		if ((rDD.s.hi == 0.0) && (!crt_isnan(aDD.s.hi) ||
60                                          !crt_isnan(bDD.s.hi)))
61		{
62			real.s.hi = crt_copysign(CRT_INFINITY,cDD.s.hi) * aDD.s.hi;
63			real.s.lo = 0.0;
64			imag.s.hi = crt_copysign(CRT_INFINITY,cDD.s.hi) * bDD.s.hi;
65			imag.s.lo = 0.0;
66		}
67
68		else if ((crt_isinf(aDD.s.hi) || crt_isinf(bDD.s.hi)) &&
69                         crt_isfinite(cDD.s.hi) && crt_isfinite(dDD.s.hi))
70		{
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		{
82			makeFinite(cDD);
83			makeFinite(dDD);
84			real.s.hi = 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 = crt_copysign(0.0,(bDD.s.hi*cDD.s.hi - aDD.s.hi*dDD.s.hi));
87			imag.s.lo = 0.0;
88		}
89	}
90
91	long double _Complex z;
92	__real__ z = real.ld;
93	__imag__ z = imag.ld;
94
95	return z;
96}
97