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

[Andrew Haley]

On 4/9/19 2:36 AM, Yangfei (Felix) wrote:
>     This can pass the fuzz test and we got the same output as when the test is executed on the x86 platform.  
>     New webrev: http://cr.openjdk.java.net/~fyang/8221658/webrev.02/
>     This also incorporates the following two constraints:  
>     2. mask != 0
>     3. rshift + width <= 32/64  (width = exact_log2(mask+1))
> 
>     JTreg tested with a fastdebug build, OK? 

That looks right, thanks.

Because C2 does not mask immediate shifts, there are other lurking
bugs.  It would be good to systematically mask all immediate shift
counts throughout aarch64.ad in a separate patch.

Would you like to do that work? Thanks.

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