On Mon, Aug 5, 2013 at 11:44 AM, Mike Stump <mikest...@comcast.net> wrote:
> It is the intent for all_ones_mask_p to return true when 64 bits of ones in
> an unsigned type of width 64 when size is 64, right? Currently the code uses
> a signed type for tmask, which sets the upper bits to 1, when the value
> includes the sign bit set and the equality code does check all 128 bits of
> the the value for equality. This results in the current code returning false
> in this case. The below change is the behavior change I'm talking about.
>
> We're fixing this in the wide-int branch, and just wanted to see if someone
> wanted to argue this isn't a bug.
>
> If you want to see a small test case:
>
> typedef enum
> {
> DK_ERROR,
> DK_SORRY,
> DK_LAST_DIAGNOSTIC_KIND
> } diagnostic_t;
>
> struct diagnostic_context
> {
> int diagnostic_count[DK_LAST_DIAGNOSTIC_KIND];
> diagnostic_t *classify_diagnostic;
> };
>
> extern diagnostic_context *global_dc;
>
> bool
> seen_error (void)
> {
> return (global_dc)->diagnostic_count[(int) (DK_ERROR)] ||
> (global_dc)->diagnostic_count[(int) (DK_SORRY)];
> }
These casts to int are relics of the old days when we used K&R C and
the cast was recommended. I think that was a mistake, and we should remove
the cast and use the enumerations directly as index.
now, your issue may still stand with other test cases.
-- Gaby
