addi (RISC-V)

risc-v

Definition

addi (RISC-V)

Adds the value of register b and the sign-extended 12-bit immediate imm, storing the result in register a. The sign-extension behaviour is described in sign extension.

addi a, b, imm

Equivalent C code:

a = b + imm

Examples

Example 1

How to realise the following C code in RISC-V, given that there’s no move instruction?

int a = -372;
int b = a + 6;

Solution: We can use the addi instruction together with the zero register:

# s0 = a, s1 = b
addi s0, zero, -372
addi s1, s0, 6