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  // This C program generates the file cmplxdivide1.go. It uses the
       6  // output of the operations by C99 as the reference to check
       7  // the implementation of complex numbers in Go.
       8  // The generated file, cmplxdivide1.go, is compiled along
       9  // with the driver cmplxdivide.go (the names are confusing
      10  // and unimaginative) to run the actual test. This is done by
      11  // the usual test runner.
      12  //
      13  // The file cmplxdivide1.go is checked in to the repository, but
      14  // if it needs to be regenerated, compile and run this C program
      15  // like this:
      16  //	gcc '-std=c99' cmplxdivide.c && a.out >cmplxdivide1.go
      17  
      18  #include <complex.h>
      19  #include <math.h>
      20  #include <stdio.h>
      21  #include <string.h>
      22  
      23  #define nelem(x) (sizeof(x)/sizeof((x)[0]))
      24  
      25  double f[] = {
      26  	0.0,
      27  	-0.0,
      28  	1.0,
      29  	-1.0,
      30  	2.0,
      31  	NAN,
      32  	INFINITY,
      33  	-INFINITY,
      34  };
      35  
      36  char* fmt(double g) {
      37  	static char buf[10][30];
      38  	static int n;
      39  	char *p;
      40  
      41  	p = buf[n++];
      42  	if(n == 10) {
      43  		n = 0;
      44  	}
      45  
      46  	sprintf(p, "%g", g);
      47  
      48  	if(strcmp(p, "0") == 0) {
      49  		strcpy(p, "zero");
      50  		return p;
      51  	}
      52  
      53  	if(strcmp(p, "-0") == 0) {
      54  		strcpy(p, "-zero");
      55  		return p;
      56  	}
      57  
      58  	return p;
      59  }
      60  
      61  int main(void) {
      62  	int i, j, k, l;
      63  	double complex n, d, q;
      64  
      65  	printf("// skip\n");
      66  	printf("// # generated by cmplxdivide.c\n");
      67  	printf("\n");
      68  	printf("package main\n");
      69  	printf("\n");
      70  	printf("import \"math\"\n");
      71  	printf("\n");
      72  	printf("var (\n");
      73  	printf("\tnan     = math.NaN()\n");
      74  	printf("\tinf     = math.Inf(1)\n");
      75  	printf("\tzero    = 0.0\n");
      76  	printf(")\n");
      77  	printf("\n");
      78  	printf("var tests = []struct {\n");
      79  	printf("\tf, g complex128\n");
      80  	printf("\tout  complex128\n");
      81  	printf("}{\n");
      82  
      83  	for(i=0; i<nelem(f); i++)
      84  	for(j=0; j<nelem(f); j++)
      85  	for(k=0; k<nelem(f); k++)
      86  	for(l=0; l<nelem(f); l++) {
      87  		n = f[i] + f[j]*I;
      88  		d = f[k] + f[l]*I;
      89  		q = n/d;
      90  
      91  		printf("\t{complex(%s, %s), complex(%s, %s), complex(%s, %s)},\n",
      92  			fmt(creal(n)), fmt(cimag(n)),
      93  			fmt(creal(d)), fmt(cimag(d)),
      94  			fmt(creal(q)), fmt(cimag(q)));
      95  	}
      96  	printf("}\n");
      97  	return 0;
      98  }