#vsetvli

RISC-V

Nov 4, 2026

V Extension 1: VLEN, SEW, LMUL, vsetvli, and Vector-Length-Agnostic Code

Part 13 of the RISC-V series. Covers vector registers, VLEN, SEW, and LMUL, and the rules by which vsetvli sets vl. Running the same machine code on QEMU at VLEN 128 to 1024, a 100-element add looped 25, 13, 7, and 4 times and executed 313 to 61 instructions (813 for scalar).