RFR: 8320725: C2: Add "requires_strict_order" flag for floating-point add-reduction [v8]

[Emanuel Peter]

On Mon, 3 Jun 2024 08:35:07 GMT, Bhavana Kilambi <bkilambi at openjdk.org> wrote:

>> @Bhavana-Kilambi
>> I know we have the tests in `test/hotspot/jtreg/compiler/c2/irTests/TestDisableAutoVectOpcodes.java`, and some other reduction tests. But these do not do the specific think I would like to see.
>> 
>> I would like this:
>> - Add `no_strict_order` vs `requires_strict_order` or similar to `dump_spec`.
>> - IR match not just that there is the correct `ReductionNode`, but also that it has the `no_strict_order` or `requires_strict_order` in its dump. You can do that by using a custom regex string, rather than `IRNode.STORE_VECTOR` or similar.
>> - Then, create different tests, some where we expect ordered, some unordered vectors. Use Vector API and SuperWord examples.
>> 
>> Does that make sense?
>
> Hi @eme64 , I have modified the tests as suggested. Please review :)

@Bhavana-Kilambi The code looks good now from my side. You have a title mismatch though.
I'll run testing again, please ping me again if I don't come back within 24h.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/18034#issuecomment-2152525743