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 <math.h>
7
8#if !defined(INFINITY) && defined(HUGE_VAL)
9#define INFINITY HUGE_VAL
10#endif /* INFINITY */
11
12#define makeFinite(x)	{ \
13							(x).s.hi = __builtin_copysign(isinf((x).s.hi) ? 1.0 : 0.0, (x).s.hi); \
14							(x).s.lo = 0.0; \
15						}
16
17#define zeroNaN(x)		{ \
18							if (isnan((x).s.hi)) { \
19								(x).s.hi = __builtin_copysign(0.0, (x).s.hi); \
20								(x).s.lo = 0.0; \
21							} \
22						}
23
24long double __gcc_qadd(long double, long double);
25long double __gcc_qsub(long double, long double);
26long double __gcc_qmul(long double, long double);
27
28long double _Complex
29__multc3(long double a, long double b, long double c, long double d)
30{
31	long double ac = __gcc_qmul(a,c);
32	long double bd = __gcc_qmul(b,d);
33	long double ad = __gcc_qmul(a,d);
34	long double bc = __gcc_qmul(b,c);
35
36	DD real = { .ld = __gcc_qsub(ac,bd) };
37	DD imag = { .ld = __gcc_qadd(ad,bc) };
38
39	if (isnan(real.s.hi) && isnan(imag.s.hi))
40	{
41		int recalc = 0;
42
43		DD aDD = { .ld = a };
44		DD bDD = { .ld = b };
45		DD cDD = { .ld = c };
46		DD dDD = { .ld = d };
47
48		if (isinf(aDD.s.hi) || isinf(bDD.s.hi))
49		{
50			makeFinite(aDD);
51			makeFinite(bDD);
52			zeroNaN(cDD);
53			zeroNaN(dDD);
54			recalc = 1;
55		}
56
57		if (isinf(cDD.s.hi) || isinf(dDD.s.hi))
58		{
59			makeFinite(cDD);
60			makeFinite(dDD);
61			zeroNaN(aDD);
62			zeroNaN(bDD);
63			recalc = 1;
64		}
65
66		if (!recalc)
67		{
68			DD acDD = { .ld = ac };
69			DD bdDD = { .ld = bd };
70			DD adDD = { .ld = ad };
71			DD bcDD = { .ld = bc };
72
73			if (isinf(acDD.s.hi) || isinf(bdDD.s.hi) || isinf(adDD.s.hi) || isinf(bcDD.s.hi))
74			{
75				zeroNaN(aDD);
76				zeroNaN(bDD);
77				zeroNaN(cDD);
78				zeroNaN(dDD);
79				recalc = 1;
80			}
81		}
82
83		if (recalc)
84		{
85			real.s.hi = INFINITY * (aDD.s.hi*cDD.s.hi - bDD.s.hi*dDD.s.hi);
86			real.s.lo = 0.0;
87			imag.s.hi = INFINITY * (aDD.s.hi*dDD.s.hi + bDD.s.hi*cDD.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