Re: Assembler in Ada?

[robert_dewar@my-dejanews.com]

In article <78hvth$m36$1@remarQ.com>,
  "news.oxy.com" <Vladimir_Olensky@oxy.com> wrote:

> It sounds very funny to hear from people who did not do
> something (intentionally or not) that someone, who filled
> that gap, did not do it very good. It is better to say
> thanks that this has been done and make necessary
> improvements in documentation and provide further better
> examples.

The most useful thing you can do is to read the gcc manual
carefully, and make suggestions as to how the documentation
there on the use of the asm feature can be improved. Then
send those suggestions to the FSF, or to us, we can pass
them on!> >
> Wrong, wrong and again wrong.
> If anyone goes down to assembler level , he/she does this
> to get direct access to processor registers and set of
> operations that can be performed on them and machine
> memory otherwise there is no need to go down to such low
> level.

You definitely need to read the GCC manual, I think you
have missed the whole point of how this feature integrates
with the RTL approach used in the backend of gcc. Yes, this
is quite a complicated feature to understand and use, but
also very powerful.

> Again, this is just an example how to preserve registers
> that will be spoiled by the Asm code and nothing more.
> Usually you do not need to preserve eax at all.

Again, read the GCC manual to better understand how the
clobbers argument works, sounds like you are a bit confused
(which is not surprising this is tricky stuff!)

> Again, this is just an example  how to say translator not
> to try to improve your code and nothing more.
> There is no need to go into deep details.

Again, you are confused as to the semantics here. Volatile
does not say "do not optimize", it is a semantic statement
about side effects of an instruction (for example, an IN or
OUT instruction on the ia32 would typically be labeled as
volatile).


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