[vectorIntrinsics] RFR: 8261394: [vector] Crash with "assert(Matcher::vector_size_supported(elem_bt, length)) failed: length in range"

[Ningsheng Jian]

On Wed, 10 Feb 2021 06:06:45 GMT, Xiaohong Gong <xgong at openjdk.org> wrote:

> The crash is introduced by [1] and happens when the compiler is making an unspported vector type:
>   assert(Matcher::vector_size_supported(elem_bt, length)) failed: length in range
> Before vectorization for each vector intrinsic, the hotspot will check whether current arch supports the vector operation from several aspects like the backend implementation, the vector type and length. Once one of them is not matched, the compiler will stop the vectorization and go back to the default java implementation.
> 
> The changes in [1] missed the check for "Op_CallLeafVector". I think the double 64-bits vector is not supported to be vectorized. However, due to the missing check, the compiler continues the progress and then the crash happens.
> 
> This patch fixes it by making sure the check contains all opcodes.
> 
> [1] https://bugs.openjdk.java.net/browse/JDK-8261267

Looks good to me, but perhaps @sviswa7 may take a look as well?

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Marked as reviewed by njian (Committer).

PR: https://git.openjdk.java.net/panama-vector/pull/38