Download E500ABIUG: PowerPC e500 Application Binary Interface User's Guide

Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
Coding Examples
C code
Assembly code
extern int src;
extern int dst;
extern int *ptr;
.extern src
.extern dst
.extern ptr
dst = src;
addis
lwz
addis
stw
r6,r0,src@ha
r0,src@1(r6)
r7,r0,dst@ha
r0,dst@1(r7)
ptr = &dst;
addis
addi
addis
stw
r6,r0,dst@ha
r0,r6,dst@1
r7,r0,ptr@ha
r0,ptr@1(r7)
*ptr = src;
addis
lwz
addis
lwz
stw
r6,r0,src@ha
r0,src@1(r6)
r7,r0,ptr@ha
r7,ptr@1(r7)
r0,0(r7)
Figure 2-36. Absolute Load and Store
NOTE
In the examples that follow, the assembly syntax symbol@got
refers to the offset in the global offset table at which the value
of symbol (that is, the address of the variable whose name is
symbol) is stored, assuming that the offset is no larger than 16
bits. The syntax symbol@got@ha, symbol@got@h, and
symbol@got@l refer to the high-adjusted, high, and low parts
of that offset, when the offset may be greater than 16 bits.
Figure 2-37 shows small model position-independent load and store operations.
C code
Assembly code
extern int src;
extern int dst;
extern int *ptr;
.extern src
.extern dst
.extern ptr
.text
# Assumes GOT pointer in r31
dst = src;
lwz
lwz
lwz
stw
r6,src@got(r31)
r7,dst@got(r31)
r0,0(r6)
r0,0(r7)
ptr = &dst;
lwz
lwz
stw
r0,dst@got(r31)
r7,ptr@got(r31)
r0,0(r7)
*ptr = src;
lwz
lwz
lwz
lwz
stw
r6,src@got(r31)
r7,ptr@got(r31)
r0,0(r6)
r7,0(r7)
r0,0(r7)
Figure 2-37. Small Model Position-Independent Load and Store
Figure 2-38 shows large model position-independent load and store operations.
Chapter 2. Low-Level System Information
For More Information On This Product,
Go to: www.freescale.com