[PATCH] Add support for ARM modified immediate syntax

[Mihail Popa]

Just for the record, attached is the patch which fixes the code deciding
whether an immediate is in canonic encoding.

Regards,
Mihai


On Fri, Aug 23, 2013 at 12:04 PM, Mihail Popa <mihail.popa at gmail.com> wrote:

> > This isn't quite right. "#1, #30" is not canonical, for example (I
> > only know this because I made the same mistake in my patch at first).
>
> Yes, indeed. Thanks for spotting that.
>
> Mihai
>
>
> On Thu, Aug 22, 2013 at 11:46 AM, Tim Northover <t.p.northover at gmail.com>wrote:
>
>> Hi Mihai,
>>
>> I think the approach is interesting, but a dead end. It cements the
>> duplicated instructions rather than moving towards unification.
>>
>> http://llvm-reviews.chandlerc.com/D1432 *does* move that way (and also
>> converts "add r0, #0, #0" back into "add r0, #0" automatically).
>>
>> That said, I did have a look at the code and spotted this:
>>
>> +  static inline bool isSOImmCanonical(unsigned Val, unsigned Rot) {
>> +    if (Rot == 0) return true;
>> +    if (Val == 0 && Rot != 0) return false;
>> +    return (Val % 4) != 0;
>> +  }
>>
>> This isn't quite right. "#1, #30" is not canonical, for example (I
>> only know this because I made the same mistake in my patch at first).
>>
>> Cheers.
>>
>> Tim.
>>
>
>
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