RFR: 8273416: C2: assert(false) failed: bad AD file after JDK-8252372 with UseSSE={0,1}

[Aleksey Shipilev]

On Thu, 28 Oct 2021 20:21:49 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> See the bug report for reproducer and failure message. I think the newly added `CastDD`/`CastFF` nodes should handle the extended `regDPR`/`regFPR` (which includes FPU "registers") instead of just `regD`/`regF` to avoid this mismatch error when `UseSSE < 2`.
>> 
>> Unfortunately, we cannot just use `reg*PR` operands in existing match rules, because those operands are defined as `UseSSE < 2`, and using them as operands and `ideal_regs()` would break the matching on `UseSSE >= 2`. Therefore I had to add another pair of matches.
>> 
>> Additonal testing:
>>  - [x] Linux x86_32 `tier1` `-XX:UseAVX=0 -XX:UseSSE=0`
>>  - [x] Linux x86_32 `tier1` default
>>  - [x] Linux x86_64 `tier1` default
>
> Good.

Thanks @vnkozlov. @rwestrel, you good with this?

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

PR: https://git.openjdk.java.net/jdk/pull/5386