RFR: 8346039: [BACKOUT] - [C1] LIR Operations with one input should be implemented as LIR_Op1

[Martin Doerr]

On Wed, 11 Dec 2024 20:41:29 GMT, David Holmes <dholmes at openjdk.org> wrote:

> Revert "8345609: [C1] LIR Operations with one input should be implemented as LIR_Op1"
> 
> This reverts commit a21d21f4d7b74e21f68b6bf9c5dc9ba7d3f9963c.
> 
> Testing tiers 1-3 in progress
> 
> Thanks

Thanks for confirming!
@vnkozlov: Regarding the redo: Do you think we can remove the separate case https://github.com/openjdk/jdk/blob/64fad1c7d374bbc635bad3b1fa7941379f39565f/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp#L3802 and fall back to `xorps` in C1? That would simplify the code a lot and avoid an extra temp register and the preloading with `LIR_OprFact::floatConst(-0.0)`?

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PR Comment: https://git.openjdk.org/jdk/pull/22690#issuecomment-2537305177