RFR: 8296426: x86: Narrow UseAVX and UseSSE flags

Vladimir Kozlov kvn at openjdk.org
Tue Nov 8 03:21:32 UTC 2022


On Fri, 4 Nov 2022 20:28:57 GMT, Claes Redestad <redestad at openjdk.org> wrote:

> This patch narrows down the UseAVX and UseSSE flags to their actual supported range and uses int rather than intx for their type. This avoids need for some silly casts, and surprisingly has a small beneficial effect to binary size (-4kb libjvm on linux-x64)
> 
> This changes behavior of previously in-range values: `-XX:UseAVX=4` would emit a strongly worded warning, but with the proposed change we'll instead terminate the JVM with an error similar to `-XX:UseAVX=100`. I believe this is too trivial for a CSR, since it only changes behavior for unsupported values.

You need to fix these flags type in JVMCI too. JVMCI tests failed.

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Changes requested by kvn (Reviewer).

PR: https://git.openjdk.org/jdk/pull/10997


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