I have “GNU assembler (GNU Binutils for Ubuntu) 2.42” for riscv64 but it does not know the IME instructions such as vmadot. I think this is the xsmtvdot extension. I do not use cross-compiling, just native development on ubuntu. Will a native binutils be available, or source code so I can build it myself? Or maybe I need a different -march option to enable the AI opcodes.
Yes, it’s the xsmtvdot extension. GCC has merged support for it, but Binutils hasn’t yet. Here is the latest patch for v5 Re: [PING^3][v2] RISC-V: Add SpacemiT vendor extensions xsmtvdot
What is the base on which that patch is to be applied?
A binutils release seems to come out every 3 months and it has now been 3 months since 2.46 but I can’t tell if this has been accepted yet.
In the Bianbu system provided by SpacemiT, the native binutils supports these instructions. However, if you are using other distributions, you will need to build it yourself. The patch is still under review and has not been merged yet. Nevertheless, I am confident that it should apply cleanly to version 2.46 and later (such as the current latest development branch) without any conflicts.