lb
Load byte (sign-extended)
Loads one byte from the address $t2 plus an offset into $t1, sign-extended to 32 bits.
Used in
- Loads, stores and immediatesMIPS assembly
Forms
lb , ()
Pseudo-instructions
The assembler turns these into one or more real instructions.
-
Read from label's address, reached through the %hi already in $t2
Set $t1 to sign-extended 8-bit value from effective memory byte address
Operands
$t1- Any general-purpose register,
$0to$31, using its numeric or named spelling, such as$8or$t0($zerois$0;$rais$31). imm16- A signed 16-bit immediate,
-32768to32767. $t2- A general-purpose register. It may be the same register as
$t1. label- A named address in the program, such as the start of a loop or a variable in
.data. imm- An immediate value: a signed 16-bit value (
-32768to32767), an unsigned 16-bit value (0to65535) or a 32-bit value (-2147483648to4294967295). The assembler chooses a supported encoding for the value and other operands; a pseudoinstruction may expand into several instructions. imm32- A 32-bit immediate,
-2147483648to4294967295. Pseudoinstruction expansion may overwrite$at, losing its previous value.
A byte with value 0xFF becomes -1 (0xFFFFFFFF) in $t1. Use 'lbu' if you want zero-extension (0 to 255 range).
.data
value: .byte 0xFF
.text
# Load byte 0xFF. Inspect $t0: 0xFFFFFFFF (-1) with sign extension.
la $t1, value
lb $t0, 0($t1)