On Fri, Nov 01, 2024 at 11:12:29AM +0000, Richard Earnshaw (lists) wrote:
> As Jakub said in the PR, this is really just papering over a general problem
> in the compiler. As such, it's OK for the gcc-14 branch, if we really need
> it, but not really suitable for trunk.
>
> I think the problem is related to failing to correclty canonicalize
> non-standard bool types in trunk_int_for_mode. The code there has:
>
> /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
> if (smode == BImode)
> return c & 1 ? STORE_FLAG_VALUE : 0;
>
> and that means we fail to generate canonical boolean values, so later on the
> compiler asserts when trying to pick non-standard values out.
>
> Perhaps instead we need something like:
>
> /* Canonicalize scalar boolean modes to 0 and STORE_FLAG_VALUE. */
> if (smode >= MIN_MODE_BOOL && smode <= MAX_MODE_BOOL)
> return c & 1 ? STORE_FLAG_VALUE : 0;
>
> Jakub?
A mode which has 4 or 16 possible valid values, not just 2, shouldn't be
considered a boolean mode, it is a partial int.
Jakub
