1 // Copyright 2010 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4
5 // gcc '-std=c99' cmplxdivide.c && a.out >cmplxdivide1.go
6
7 #include <complex.h>
8 #include <math.h>
9 #include <stdio.h>
10 #include <string.h>
11
12 #define nelem(x) (sizeof(x)/sizeof((x)[0]))
13
14 double f[] = {
15 0,
16 1,
17 -1,
18 2,
19 NAN,
20 INFINITY,
21 -INFINITY,
22 };
23
24 char*
fmt(double g)25 fmt(double g)
26 {
27 static char buf[10][30];
28 static int n;
29 char *p;
30
31 p = buf[n++];
32 if(n == 10)
33 n = 0;
34 sprintf(p, "%g", g);
35 if(strcmp(p, "-0") == 0)
36 strcpy(p, "negzero");
37 return p;
38 }
39
40 int
iscnan(double complex d)41 iscnan(double complex d)
42 {
43 return !isinf(creal(d)) && !isinf(cimag(d)) && (isnan(creal(d)) || isnan(cimag(d)));
44 }
45
46 double complex zero; // attempt to hide zero division from gcc
47
48 int
main(void)49 main(void)
50 {
51 int i, j, k, l;
52 double complex n, d, q;
53
54 printf("// skip\n");
55 printf("// # generated by cmplxdivide.c\n");
56 printf("\n");
57 printf("package main\n");
58 printf("var tests = []Test{\n");
59 for(i=0; i<nelem(f); i++)
60 for(j=0; j<nelem(f); j++)
61 for(k=0; k<nelem(f); k++)
62 for(l=0; l<nelem(f); l++) {
63 n = f[i] + f[j]*I;
64 d = f[k] + f[l]*I;
65 q = n/d;
66
67 // BUG FIX.
68 // Gcc gets the wrong answer for NaN/0 unless both sides are NaN.
69 // That is, it treats (NaN+NaN*I)/0 = NaN+NaN*I (a complex NaN)
70 // but it then computes (1+NaN*I)/0 = Inf+NaN*I (a complex infinity).
71 // Since both numerators are complex NaNs, it seems that the
72 // results should agree in kind. Override the gcc computation in this case.
73 if(iscnan(n) && d == 0)
74 q = (NAN+NAN*I) / zero;
75
76 printf("\tTest{complex(%s, %s), complex(%s, %s), complex(%s, %s)},\n",
77 fmt(creal(n)), fmt(cimag(n)),
78 fmt(creal(d)), fmt(cimag(d)),
79 fmt(creal(q)), fmt(cimag(q)));
80 }
81 printf("}\n");
82 return 0;
83 }
84