[aarch64-port-dev ] RFR: 8221658: aarch64: add necessary predicate for ubfx patterns

[Andrew Haley]

On 4/1/19 2:19 AM, Yangfei (Felix) wrote:
> The patch adds the following three constraints for 'rshift' and 'mask' operands:
> 
>     1. 0 <= rshift <=31/63
>     2. mask != 0
>     3. rshift + width <= 32/64  (width = exact_log2(mask+1))
> 
>     Constraint 3 needs to be implemented by adding a predicate as we are checking both 'rshift' and 'mask' operands. 
> 
>     Do you want me to implement constraint 1 & 2 using a match operand? 

Yes. Please do so wherever possible.

-- 
Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
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