[patch][pr22947] Use sext in fast isel

[Rafael Espíndola]

ping

On 2 April 2015 at 13:28, Rafael Espíndola <rafael.espindola at gmail.com> wrote:
> ping
>
> On 27 March 2015 at 14:00, Rafael Espíndola <rafael.espindola at gmail.com> wrote:
>> ping
>>
>> On 18 March 2015 at 11:45, Rafael Espíndola <rafael.espindola at gmail.com> wrote:
>>> Fast isel currently has a bug in that it zero extends immediates to 64
>>> bits. This normally goes unnoticed because the value is truncated to
>>> 32 bits for output.
>>>
>>> Two cases were it is noticed:
>>>
>>> * We fail to use smaller encodings.
>>> * If the original constant was smaller than i32.
>>>
>>> For example, the only possible values for i1 are 0 and -1, yet we were
>>> expanding -1 to i32 1.
>>>
>>> Cheers,
>>> Rafael