RFR: 8339790: Support Intel APX setzucc instruction [v6]
Sandhya Viswanathan
sviswanathan at openjdk.org
Tue Sep 17 17:14:09 UTC 2024
On Tue, 17 Sep 2024 16:35:43 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:
>> - Support APX variant of SETcc, which supports zero-upper semantics (full register writer). Sets the destination operand to 0 or 1 depending on the settings of the status flags (CF, SF, OF, ZF, and PF) in the EFLAGS register. The destination operand points to a byte register or a byte in memory. The
>> condition code suffix (cc) indicates the condition being tested for. Additionally, if ND = 1 and the destination is a GPR, then also set the upper 56 bits of the GPR to 0.
>> - This saves emitting an explicit MOVZX instruction after setCC.
>> - These new instructions are encoded using 4 byte Extended EVEX encoding.
>>
>> Validation performed over stand alone test point using Intel SDE.
>>
>> Best Regards,
>> Jatin
>
> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
>
> Post NDD patch cleanups
LGTM
-------------
Marked as reviewed by sviswanathan (Reviewer).
PR Review: https://git.openjdk.org/jdk/pull/20920#pullrequestreview-2310353618
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