Program Structure

Registers and Register Mnemonics

This warning can be suppressed with the -w41command-line option. Future versions of the Assembler may not always allow an absolute expression where a register is expected.

The following example demonstrates the correct usage of the .REG directive:

tblptr .REG %r20 aka_tbl .REG tblptr

Predefined registers are shown in the following tables. All of the mnemonics begin with the % character, so they do not conflict with any programmer-defined symbols.

Table 2-2

General Registers

 

 

 

 

 

 

 

 

%r0

%r8

%r16

%r24

 

%r1

%r9

%r17

%r25

 

%r2

%r10

%r18

%r26

 

%r3

%r11

%r19

%r27

 

%r4

%r12

%r20

%r28

 

%r5

%r13

%r21

%r29

 

%r6

%r14

%r22

%r30

 

%r7

%r15

%r23

%r31

 

 

 

 

 

Chapter 2

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