VSETVL

Vector Set VL

VSETVL rd, rs1, rs2

Sets the vector length (VL) based on the application vector length (AVL) in rs1 and configuration in rs2.

Details

Sets the vector length (vl) and vector type (vtype) registers based on the requested application vector length (AVL) and element width/grouping. The actual vector length set is written to rd. vtype encodes SEW (element width), LMUL (register grouping), and tail/mask policies.

Pseudocode Operation

vl = set_config(rs1, rs2); R[rd] = vl;

Example

VSETVL t0, a0, a1

Encoding

Binary Layout
1000000
31:25
rs2
24:20
rs1
19:15
111
14:12
rd
11:7
1010111
6:0
 
Format V-Type
Opcode 0x57
Extension V

Operands

  • rd
    Dest (New VL)
  • rs1
    AVL
  • rs2
    Config (VTYPE)