How to change vector extension configuration(vlen, elen)?

[Seo-sang]

Hello, I have a problem when building spike with --with-varch option and I found varch option is removed two month ago. Then, how to change vector configuration? Downloading the version before it removed the only way to change them?
Thank you.

[jerryz123]

This is done at runtime with the zvl/zve isa strings now.

For example, you can specify --isa=rv64gcv_zvl512b_zve64d

No flags need to be passed to the configure script.

[Seo-sang]

Oh, I see. Thank you for your immediate response👍

[Seo-sang]

@jerryz123 I have one more question. Even though I set --isa=rv64gcv_zvl128b_zve32f, elen isn't changed and it seems that elen cannot be smaller than 64-bit in isa_parser.cc file line 349. How can I set elen to 32-bit?
Thank you.

[jerryz123]

v extension requires zve64d, and zve32f is a subset of zve64d (zve32f does not imply zve64d is not available).

You can do rv64gc_zvl128b_zve32f to get a machine with ELEN=32.