ADD.UW

Add Unsigned Word

ADD.UW rd, rs1, rs2

Zero-extends the lower 32 bits of rs1 and adds it to rs2. Useful for 64-bit address calculations with 32-bit unsigned indices.

Encoding

Binary Layout

0000100

31:25

rs2

24:20

rs1

19:15

000

14:12

rd

11:7

0111011

6:0

 

Format R-Type

Opcode 0x0800003B

Extension Zba

Operands

• rd
  Destination register (integer)
• rs1
  Index (32-bit)
• rs2
  Base

Example

ADD.UW x10, x11, x12

// x10 = x12 + (uint32_t)x11

Related

More in Zba

Reference

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

Description

ADD.UW zero-extends the lower 32 bits of rs1 to XLEN bits, adds the result to rs2, and writes to rd. Used for pointer arithmetic with zero-extended 32-bit offsets.

Operation

R[rd] = R[rs2] + zext(R[rs1][31:0]);