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Assembler Language Reference

lwz or l (Load Word and Zero) Instruction

Purpose

Loads a word of data from a specified location in memory into a general-purpose register.

Syntax

Bits Value
0-5 32
6-10 RT
11-15 RA
16-31 D
PowerPC 
lwz RT, D( RA)
POWER family 
l RT, D( RA)

Description

The lwz and l instructions load a word in storage from a specified location in memory addressed by the effective address (EA) into the target general-purpose register (GPR) RT.

If GPR RA is not 0, the EA is the sum of the contents of GPR RA and D, a 16-bit, signed two's complement integer sign-extended to 32 bits. If GPR RA is 0, then the EA is D.

The lwz and l instructions have one syntax form and do not affect the Fixed-Point Exception Register or Condition Register Field 0.

Parameters

RT Specifies target general-purpose register where result of operation is stored.
D Specifies a 16-bit, signed two's complement integer sign-extended to 32 bits for EA calculation.
RA Specifies source general-purpose register for EA calculation.

Examples

The following code loads a word from memory into GPR 6:

.csect data[rw]
# Assume GPR 5 contains address of csect data[rw].
storage: .long 0x4
.csect text[pr]
lwz 6,storage(5)
# GPR 6 now contains 0x0000 0004.

Related Information

Fixed-Point Processor .

Fixed-Point Load and Store Instructions .

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