Date:	Wed, 21 Jun 2000 07:20:06 +0300 (IDT)
From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender:	eliz AT is
To:	Richard Dawe <rich AT phekda DOT freeserve DOT co DOT uk>
cc:	djgpp AT delorie DOT com
Subject:	Re: Inline asm: lcall & various binutils versions
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On Tue, 20 Jun 2000, Richard Dawe wrote:

> #if GAS_MAJOR >= 2 && GAS_MINOR > 8
> 		 "nop	\r\n"
> #endif	/* IFDEFTEST */
> 		 "nop	\r\n");

I understand that this is just an example, because in the actual problem 
you had you will need a different condition for the versions (e.g., if 
GAS_MAJOR is 3 or more, GAS_MINOR is not important).

> Is this
> satisfactory? My sed knowledge is limited (*), but this seems to do the
> trick.

The Sed scripts can be improved slightly, but they seem to be correct.

> It took me a while to work out how to put #ifdefs in inline assembly. Eli,
> you probably knew this already, but: You have to rely on C's string
> concatenation.

For inline assembly, you need to rely on the preprocessor to do the 
trick when it works on the C source, so the #ifdef's need to be on the C 
level, not on the assembly level.

> [ If you put '#ifdef' in the inline assembly, then it becomes an assembly
> comment and does nothing.

AFAIK, inline assembly doesn't go through cpp; GCC emits it in the
form of preprocessed assembly.  So you cannot have any preprocessor 
directives inside the asm() block.

> This feels like less of a hack than relying on gas to generate the right
> code in spite of a warning.

More importantly, it's safer ;-)

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