Chapter 19.

HPPA Dependent Features

19.1. Notes

As a back end for gnu cc

as

has been throughly tested and should work extremely well. We have

tested it only minimally on hand written assembly code and no one has tested it much on the assembly

output from the HP compilers.

The format of the debugging sections has changed since the original

as

port (version 1.3X) was

released; therefore, you must rebuild all HPPA objects and libraries with the new assembler so that

you can debug the final executable.

The HPPA

as

port generates a small subset of the relocations available in the SOM and ELF object

file formats. Additional relocation support will be added as it becomes necessary.

19.2. Options

as

has no machine dependent command line options for the HPPA.

19.3. Syntax

The assembler syntax closely follows the HPPA instruction set reference manual; assembler direc 

tives and general syntax closely follow the HPPA assembly language reference manual, with a few

noteworthy differences.

First, a colon may immediately follow a label definition. This is simply for compatibility with how

most assembly language programmers write code.

Some obscure expression parsing problems may affect hand written code which uses the

spop

in 

structions, or code which makes significant use of the

!

line separator.

as

is much less forgiving about missing arguments and other similar oversights than the HP assembler.

as

notifies you of missing arguments as syntax errors; this is regarded as a feature, not a bug.

Finally,

as

allows you to use an external symbol without explicitly importing the symbol. Warning:

in the future this will be an error for HPPA targets.

Special characters for HPPA targets include:

;

is the line comment character.

!

can be used instead of a newline to separate statements.

Since

$

has no special meaning, you may use it in symbol names.

19.4. Floating Point

The HPPA family uses ieee floating point numbers.