mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-07 13:54:33 +00:00
89 lines
2.3 KiB
C
89 lines
2.3 KiB
C
/* go-matherr.c -- a Go version of the matherr function.
|
|
|
|
Copyright 2012 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. */
|
|
|
|
/* The gccgo version of the math library calls libc functions. On
|
|
some systems, such as Solaris, those functions will call matherr on
|
|
exceptional conditions. This is a version of matherr appropriate
|
|
for Go, one which returns the values that the Go math library
|
|
expects. This is fine for pure Go programs. For mixed Go and C
|
|
programs this will be problematic if the C programs themselves use
|
|
matherr. Normally the C version of matherr will override this, and
|
|
the Go code will just have to cope. If this turns out to be too
|
|
problematic we can change to run pure Go code in the math library
|
|
on systems that use matherr. */
|
|
|
|
#include <math.h>
|
|
#include <stdint.h>
|
|
|
|
#include "config.h"
|
|
|
|
#if defined(HAVE_MATHERR) && defined(HAVE_STRUCT_EXCEPTION)
|
|
|
|
#define PI 3.14159265358979323846264338327950288419716939937510582097494459
|
|
|
|
int
|
|
matherr (struct exception* e)
|
|
{
|
|
const char *n;
|
|
|
|
if (e->type != DOMAIN)
|
|
return 0;
|
|
|
|
n = e->name;
|
|
if (__builtin_strcmp (n, "acos") == 0
|
|
|| __builtin_strcmp (n, "asin") == 0)
|
|
e->retval = __builtin_nan ("");
|
|
else if (__builtin_strcmp (n, "atan2") == 0)
|
|
{
|
|
if (e->arg1 == 0 && e->arg2 == 0)
|
|
{
|
|
double nz;
|
|
|
|
nz = -0.0;
|
|
if (__builtin_memcmp (&e->arg2, &nz, sizeof (double)) != 0)
|
|
e->retval = e->arg1;
|
|
else
|
|
e->retval = copysign (PI, e->arg1);
|
|
}
|
|
else
|
|
return 0;
|
|
}
|
|
else if (__builtin_strcmp (n, "log") == 0
|
|
|| __builtin_strcmp (n, "log10") == 0)
|
|
e->retval = __builtin_nan ("");
|
|
else if (__builtin_strcmp (n, "pow") == 0)
|
|
{
|
|
if (e->arg1 < 0)
|
|
e->retval = __builtin_nan ("");
|
|
else if (e->arg1 == 0 && e->arg2 == 0)
|
|
e->retval = 1.0;
|
|
else if (e->arg1 == 0 && e->arg2 < 0)
|
|
{
|
|
double i;
|
|
|
|
if (modf (e->arg2, &i) == 0 && ((int64_t) i & 1) == 1)
|
|
e->retval = copysign (__builtin_inf (), e->arg1);
|
|
else
|
|
e->retval = __builtin_inf ();
|
|
}
|
|
else
|
|
return 0;
|
|
}
|
|
else if (__builtin_strcmp (n, "sqrt") == 0)
|
|
{
|
|
if (e->arg1 < 0)
|
|
e->retval = __builtin_nan ("");
|
|
else
|
|
return 0;
|
|
}
|
|
else
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
#endif
|