How to configure config to generate a cross toolchain that supports riscv extension vectors？

[skychengzhixing]

hi，friend：
I want to use version 1.25.0 of Crosstool-ng to generate a cross toolchain that supports riscv extension vectors. How can I config for this?
Which options do I need to configure?
Looking forward to your reply!

[QBos07]

Looks like that gcc supports vector extensions out of the box and you can enable automatic vectorization by compiling with the -mrvv flag but please don't quote me on that since I just did a quick google search.

[QBos07]

Btw I recommend using ct-ng from master but 1.26 is near (see #1991). This is mostly due to some changed download paths.

[KirillSmirnov]

It depends on a version of the vector extension. To the best of my knowledge, the only hardware implementation available for customers is rvv0.7. rvv1.0 is for qemu and other virtual environments only. Please, tell me if I am wrong!

If you are interested in rvv1.0, the latest gcc supports it out of the box, so you can just grab crosstool-ng master and build riscv64-unknown-linux-gnu (or other) sample. To use the extension just pass -march=....v option to gcc, for example, -march=rv64gcv. -mrvv flag won't work.
If you are interested in rvv0.7, the best way is use pre-built toolchain supplied by the vendor of your hardware.

[skychengzhixing]

Thank you for your answers.
I have added the following options to the configuration, which currently appear to be effective, as follows:
CT_CC_GCC_EXTRA_CONFIG_ARRAY="--with-march=rv64gc --with-march=rv64gcv”.