Gas can't handle prefix generated by gcc
H. J. Lu
Fri Jul 23 20:51:00 GMT 2004
On Fri, Jul 23, 2004 at 01:43:33PM -0700, Zack Weinberg wrote:
> "H. J. Lu" <email@example.com> writes:
> > On Fri, Jul 23, 2004 at 12:49:48PM -0700, Zack Weinberg wrote:
> >> Zack Weinberg <firstname.lastname@example.org> writes:
> >> > "H. J. Lu" <email@example.com> writes:
> >> >
> >> >> It seems that gcc uses a prefix syntax which gas doesn't handle. Does
> >> >> gcc always use " ; " as prefix separator?
> >> >
> >> > Yes. It does that for cs/ds on branch hints, it does that for "rep"
> >> > on string instructions, it does that for "lock" on atomic updates.
> >> Correction - it uses either " ; " or \n\t in all the above cases.
> > It looks like a gcc bug to me. Assembler has a way to define prefixes
> > for an instruction. Unfortunately, gcc uses something else. I will
> > close the assembler bug.
> Not so fast. Is the PREFIX_SEPARATOR mechanism (a) supported by GAS
> since time immemorial, and (b) supported by all other i386 assemblers
> since time immemorial? If *either* of those is not true, GCC can't
It was added to gas on Jun 8, 1998. It is trivial to add a configure
test before using it. Gcc has many feature tests for assembler.
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