RFR: 8297417: Poly1305IntrinsicFuzzTest fails with tag mismatch exception [v2]

[Vladimir Ivanov]

On Wed, 23 Nov 2022 20:01:37 GMT, Volodymyr Paprotski <duke at openjdk.org> wrote:

>> From https://github.com/openjdk/jdk/pull/10582, `t0` gets clobbered if `rscratch` is used. Example, [here](https://github.com/openjdk/jdk/blob/09f70dad2fe3f0691afacded6c38f61fa8a0d28d/src/hotspot/cpu/x86/stubGenerator_x86_64_poly.cpp#L605-L606): 
>> 
>> 
>>   __ mov(t0, a0);
>>   __ andq(t0, ExternalAddress(poly1305_mask44()), rscratch); // First limb (R^4[43:0])
>
> Volodymyr Paprotski has updated the pull request incrementally with one additional commit since the last revision:
> 
>   remove rscratch from top regmap and ForceUnreachable test

test/jdk/com/sun/crypto/provider/Cipher/ChaCha20/unittest/Poly1305UnitTestDriver.java line 52:

> 50:  * @modules java.base/com.sun.crypto.provider
> 51:  * @summary Unit test for IntrinsicCandidate in com.sun.crypto.provider.Poly1305.
> 52:  * @run main/othervm -Xcomp -XX:-TieredCompilation -XX:+ForceUnreachable java.base/com.sun.crypto.provider.Poly1305IntrinsicFuzzTest

Don't you need `-XX:+UnlockDiagnosticVMOptions` here as well?

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PR: https://git.openjdk.org/jdk/pull/11308