Hi Lehua, I once had different comments for those but either I never pushed them or they got buried in the process of refactoring. The explanatory comment explaining vlmax is also in "nowhere land" below autovec_use_vlmax_p. (it says vsetvli instead of vsetvl as well...) It would be useful to move it to above the function comments you touch.
> +/* Emit RVV insn which vl is the number of units of the vector mode. > + This function can only be used before LRA pass or for VLS_AVL_IMM modes. > */ Emit an RVV insn with a vector length that equals the number of units of the vector mode. For VLA modes this corresponds to VLMAX. Unless the vector length can be encoded in the vsetivl[i] instruction this function must only be used as long as we can create pseudo registers. This is because it will set a pseudo register to VLMAX using vsetvl and use this as definition for the vector length. Besides, we could add a const_vlmax_p () || can_create_pseudo_p assert here? > +/* Like emit_vlmax_insn but can be only used after LRA pass that can't create > + pseudo register. */ Like emit_vlmax_insn but must only be used when we cannot create pseudo registers anymore. This function, however, takes a predefined vector length from the value in VL. > +/* Emit RVV insn which vl is the VL argument. */ > +emit_nonvlmax_insn (unsigned icode, unsigned insn_flags, rtx *ops, rtx vl) I think I renamed this to emit_len_insn or something before but Juzhe didn't like it ;) How about something like: Emit an RVV insn with a predefined vector length. Contrary to emit_vlmax_insn the instruction's vector length is not deduced from its mode but taken from the value in VL. Regards Robin
