[RFA:] Fix bug with #APP/#NO_APP when using macros.

[Ian Lance Taylor]

Zack Weinberg <zack@codesourcery.com> writes:

> Ian Lance Taylor <ian@airs.com> writes:
> 
> > I take your point, though, which is that though targets other than
> > CRIS and m68k emit #APP/#NO_APP around assembler statements, it is
> > ineffective and pointless.
> 
> And since no one has noticed this up to now, does that mean that there
> is no real performance benefit to be had from #NO_APP, and we can blow
> away all the code that emits it from gcc?

I don't think we can conclude that.  There must be some performance
benefit from #NO_APP, since in that case gas does not have to call
do_scrub_chars().  However, the benefit may be insignificant.  We
would need to do some timing tests.

> Or should gcc be changed to emit #NO_APP at file start?

You can't do it blindly.  You have to make sure that the gcc output is
consistent with what the assembler expects when it does not scrub.
The assembler input must not contain any comments, and must not
contain any extra whitespace.  At least some gcc targets do not meet
these conditions.  For example, I happen to know that the MIPS backend
does not.

Ian