ADDI — add immediate

addi rd, rs1, imm12

Adds a sign-extended 12-bit immediate: rd = rs1 + sign_extend(imm12). The range is −2048 through 2047. Available in RV32I and RV64I.

addi sp, sp, -32       # allocate 32 bytes of stack space
addi a0, a0, 1         # increment a0

Common pseudoinstructions: mv rd, rs uses an immediate of zero; nop is addi x0, x0, 0.

x86 connection: resembles add reg, imm, but produces no flags and keeps separate source/destination operands.