Steve Hay wrote:
>This program
>
>#include <math.h>
>#include <stdio.h>
>void main(void) {
> double x, y;
> x = pow(9.0, 9.0);
> printf("x = %lf\n", x);
> y = pow(9.0, x);
> printf("y = %lf\n", y);
>}
>
>outputs
>
>x = 387420489.000000
>
>pow: OVERFLOW error
>y = +INF
>
>when built with Borland, whereas VC++ and GCC both give me
>
>x = 387420489.000000
>y = 1.#INF00
>
>The OVERFLOW error (and the DOMAIN error seen in lib/warnings.t) are
>presumably related to this enum in Borland's <math.h>
>
>typedef enum
>{
> DOMAIN = 1, /* argument domain error -- log (-1) */
> SING, /* argument singularity -- pow (0,-2)) */
> OVERFLOW, /* overflow range error -- exp (1000) */
> UNDERFLOW, /* underflow range error -- exp (-1000) */
> TLOSS, /* total loss of significance -- sin(10e70) */
> PLOSS, /* partial loss of signif. -- not used */
> STACKFAULT /* floating point unit stack overflow */
>} _mexcep;
>
>but I still see no way of disabling them yet. Still looking...
>
After a bit of Googling (since there is bugger all documentation with
the free commandline tools download) I think I've found the answer.
Here's a useful link: http://www.clipx.net/ng/borcpp/ng42cd3.php
So the solution is to define a _matherr() function which returns 1 to
indicate that it has handled the error, thus suppressing the stderr warning.
#include <math.h>
#include <stdio.h>
void main(void) {
double x, y;
x = pow(9.0, 9.0);
printf("x = %lf\n", x);
y = pow(9.0, x);
printf("y = %lf\n", y);
}
int _matherr(struct _exception *a) {
a->retval = a->retval;
return 1;
}
This fixes the B/t/deparse.t error, and also the lib/warnings.t error
now succeeds with change 24870 reverted.
So I've applied this (and reverted 24870) in change 24883.
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