https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109104
--- Comment #2 from JuzheZhong <juzhe.zhong at rivai dot ai> --- (In reply to Roger Sayle from comment #1) > Not exactly my area of expertise, but adding > > if (!can_create_pseudo_p ()) > return false; > > at the start of legitimize_move on line 262 of riscv-v.cc should help. > Other solutions include clearing a vector register without requiring > a scalar register (to set the vector length) by xoring it with itself, > or possibly providing a riscv backend target hook to override the default > default_zero_call_used_regs implementation. > > If the vector length can be set to zero, that might be an alternative > to clearing call-used vector registers. We (me && kito) are trying to find the solution to fix it. Actually, xoring itself can not help since vxor.vv also needs vsetvl a5,zero.... Setting vector-length to be VLMAX. We don't have an instruction in RVV ISA can zero a whole vector register without vsetvl to setting VLMAX vector-length. I think maybe Kito knows how to fix it. We will definetely fix it soon in GCC 13. Thanks.
