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Re: [PATCH (2/7)] Widening multiplies by more than one mode
On Tue, Jul 12, 2011 at 1:26 PM, Andrew Stubbs <andrew.stubbs@gmail.com> wrote:
> On 12/07/11 12:05, Richard Guenther wrote:
>>
>> (**) We really ought to forbid any arithmetic on types that have non-mode
>> precision and only allow conversions to/from such types.
>
> Hmmm, presumably the problem is that we might have a compatible precision,
> but the backends actually work with purely mode-sized types?
>
> That does sound problematic. :(
>
> Does the recent bitfield lowering activity have any affect on this? I.e.
> does it make it a moot point by the time we get to the widen_mult pass?
No, the bitfield lowering will only change the types of memory loads,
not the types of the quantities we eventually see in the IL. Thus for
my example we'd still see the casts from 7-bit types.
Richard.
> Andrew
>