mirror of
https://github.com/golang/go
synced 2024-11-23 16:30:06 -07:00
3b63b69d2f
The various files are confusingly named and their operation not easy to see. Add a comment to cmplxdivide.c, one of the few C files that will endure in the repository, to explain how to build and run the test. Change-Id: I1fd5c564a14217e1b9815b09bc24cc43c54c096f Reviewed-on: https://go-review.googlesource.com/2850 Reviewed-by: Russ Cox <rsc@golang.org>
95 lines
2.3 KiB
C
95 lines
2.3 KiB
C
// Copyright 2010 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// This C program generates the file cmplxdivide1.go. It uses the
|
|
// output of the operations by C99 as the reference to check
|
|
// the implementation of complex numbers in Go.
|
|
// The generated file, cmplxdivide1.go, is compiled along
|
|
// with the driver cmplxdivide.go (the names are confusing
|
|
// and unimaginative) to run the actual test. This is done by
|
|
// the usual test runner.
|
|
//
|
|
// The file cmplxdivide1.go is checked in to the repository, but
|
|
// if it needs to be regenerated, compile and run this C program
|
|
// like this:
|
|
// gcc '-std=c99' cmplxdivide.c && a.out >cmplxdivide1.go
|
|
|
|
#include <complex.h>
|
|
#include <math.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
#define nelem(x) (sizeof(x)/sizeof((x)[0]))
|
|
|
|
double f[] = {
|
|
0,
|
|
1,
|
|
-1,
|
|
2,
|
|
NAN,
|
|
INFINITY,
|
|
-INFINITY,
|
|
};
|
|
|
|
char*
|
|
fmt(double g)
|
|
{
|
|
static char buf[10][30];
|
|
static int n;
|
|
char *p;
|
|
|
|
p = buf[n++];
|
|
if(n == 10)
|
|
n = 0;
|
|
sprintf(p, "%g", g);
|
|
if(strcmp(p, "-0") == 0)
|
|
strcpy(p, "negzero");
|
|
return p;
|
|
}
|
|
|
|
int
|
|
iscnan(double complex d)
|
|
{
|
|
return !isinf(creal(d)) && !isinf(cimag(d)) && (isnan(creal(d)) || isnan(cimag(d)));
|
|
}
|
|
|
|
double complex zero; // attempt to hide zero division from gcc
|
|
|
|
int
|
|
main(void)
|
|
{
|
|
int i, j, k, l;
|
|
double complex n, d, q;
|
|
|
|
printf("// skip\n");
|
|
printf("// # generated by cmplxdivide.c\n");
|
|
printf("\n");
|
|
printf("package main\n");
|
|
printf("var tests = []Test{\n");
|
|
for(i=0; i<nelem(f); i++)
|
|
for(j=0; j<nelem(f); j++)
|
|
for(k=0; k<nelem(f); k++)
|
|
for(l=0; l<nelem(f); l++) {
|
|
n = f[i] + f[j]*I;
|
|
d = f[k] + f[l]*I;
|
|
q = n/d;
|
|
|
|
// BUG FIX.
|
|
// Gcc gets the wrong answer for NaN/0 unless both sides are NaN.
|
|
// That is, it treats (NaN+NaN*I)/0 = NaN+NaN*I (a complex NaN)
|
|
// but it then computes (1+NaN*I)/0 = Inf+NaN*I (a complex infinity).
|
|
// Since both numerators are complex NaNs, it seems that the
|
|
// results should agree in kind. Override the gcc computation in this case.
|
|
if(iscnan(n) && d == 0)
|
|
q = (NAN+NAN*I) / zero;
|
|
|
|
printf("\tTest{complex(%s, %s), complex(%s, %s), complex(%s, %s)},\n",
|
|
fmt(creal(n)), fmt(cimag(n)),
|
|
fmt(creal(d)), fmt(cimag(d)),
|
|
fmt(creal(q)), fmt(cimag(q)));
|
|
}
|
|
printf("}\n");
|
|
return 0;
|
|
}
|