On Tue, Jul 2, 2013 at 1:00 PM, Graydon Hoare <[email protected]> wrote:
> The largest supported _of the rust types_; I didn't (and don't) intend
> to have rust support f80 at all, since:
> - It's not an ieee754 basic format.
> - It's not a storage format; x87 loads and stores 32/64 bit values,
> it's just an intermediate state during calculation on x87 stack.
Hm?
$ cat a.c
#include <stdio.h>
void main(void) {
long double q[100];
int i;
for(i=0;i<100;i++)q[i]=i;
printf("%d\n",sizeof(q[0]));
}
$ gcc -o a.s -S a.c -m32
$ cat a.s | grep fstpt
fstpt (%eax)
$ ./a
12
At least ten years ago, I knew people who were doing numerical work
where they were still purchasing itanium hardware on the basis of long
double performance. I suppose now most of those people would spend
more cycles getting their algorithms to behave well with doubles—
considering the performance gaps... so it it indeed may be irrelevant.
But 80 bit floating point is certainly a real, if non-standard, thing!
(and absent people saying they need it, it isn't like it would be the
sort of thing that would be hard to add to a later version of the
language)
_______________________________________________
Rust-dev mailing list
[email protected]
https://mail.mozilla.org/listinfo/rust-dev
