The maximum LMUL is 8. We need 16 vector registers for two LMUL-8 arguments. The modification follows the proposal of psABI in https://github.com/riscv/riscv-elf-psabi-doc/pull/171 Differential Revision: https://reviews.llvm.org/D95134
The patterns that want to use 'vnot' use a custom PatFrag. This is because 'vnot' uses immAllOnesV which implicitly uses BUILD_VECTOR rather than SPLAT_VECTOR. Reviewed By: craig.topper Differential Revision: https://reviews.llvm.org/D94078