How do I write rotation Operation for the Risc-V(Assembly Language) Do we have any command for it like we have have in 8086?

问题

I have worked with assembly language of 8086 previously, rotation operation in 8086 was just a command. But I can't find a specific keyword for rotation operation in Risc-V assembly language.

回答1:

It looks like extension "B" should define such an instruction eventually.

Until then you have to compose it using left and right shifts.

Here's an equivalent of the MIPS32R2 rotrv instruction (rotate right by variable count):

rotrv:
    subu    neg_count, zero, count
    srlv    tmp1, src, count
    sllv    tmp2, src, neg_count
    or      dst, tmp1, tmp2

You can do the same on riscv.

来源：https://stackoverflow.com/questions/55394123/how-do-i-write-rotation-operation-for-the-risc-vassembly-language-do-we-have-a