SUB

Subtract

SUB rd, rs1, rs2

Subtracts rs2 from rs1.

Encoding

Binary Layout

0100000

31:25

rs2

24:20

rs1

19:15

000

14:12

11:7

0110011

6:0

Format R-Type

Opcode 0x40000033

Extension RV32I

Operands

rd
Destination register (integer)
rs1
Minuend
rs2
Subtrahend

Example

SUB t0, a0, a1

Reference

View in RISC-V Unprivileged ISA Specification ↗ RISC-V ISA Manual

Description

SUB subtracts the value in rs2 from rs1 and writes the result to rd. Arithmetic overflow is ignored; the result is the low XLEN bits of the mathematical difference.

Operation

R[rd] = R[rs1] - R[rs2];

SUB