RFR: 8357982: Fix several failing BMI tests with -XX:+UseAPX

[Sandhya Viswanathan]

On Wed, 28 May 2025 16:21:56 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

> A) Patch extends the following tests with hard-coded encoding checks for various BMI instructions to cover REX2 or extended EVEX encodings supported by APX. 
> 
> 
>      compiler/intrinsics/bmi/verifycode/AndnTestI.java
>      compiler/intrinsics/bmi/verifycode/AndnTestL.java
>      compiler/intrinsics/bmi/verifycode/BzhiTestI2L.java
>      compiler/intrinsics/bmi/verifycode/LZcntTestL.java
>      compiler/intrinsics/bmi/verifycode/TZcntTestL.java
> 
> 
> B) After integration of JDK-8349582, which added APX NDD support, AndN instruction selection patterns that expect (Xor SRC, -1) as one of its operands were not getting selected because of a lower-cost generic immediate pattern match; patch fixes this issue through strict predicate checks.
> 
> Above tests are now passing, validations were carried out using Intel Software Development emulator.
> 
> Kindly review and share your feedback.
> 
> Best Regards,
> Jatin

How about the other tests in the same directory: Blsi, Blsr, Blsmsk, LZcnti, TZcnti? They also need the APX encoding with higher bank register usage.

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PR Comment: https://git.openjdk.org/jdk/pull/25501#issuecomment-2923036492