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AIX Version 4.3 Assembler Language Reference

lwzx or lx (Load Word and Zero Indexed) Instruction

Purpose

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

Syntax

PowerPC
lwzx RT,RA,RB
POWER
lx RT,RA,RB

Description

The lwzx and lx instructions load a word of data 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 GPR RB. If GPR RA is 0, then the EA is the contents of GPR RB.

The lwzx and lx 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.
RA Specifies source general-purpose register for EA calculation.
RB Specifies source general-purpose register for EA calculation.

Examples

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

.csect data[rw]
.long 0xffdd 75ce
# Assume GPR 4 contains the displacement relative to
# csect data[rw].
# Assume GPR 5 contains the address of csect data[rw].
.csect text[pr]
lwzx 6,5,4
# GPR 6 now contains 0xffdd 75ce.

Related Information

Fixed-Point Processor.

Fixed-Point Load and Store Instructions.

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