GCC4 x86_64 pushfl / pop %eax inline asm ?

GCC4 x86_64 pushfl / pop %eax inline asm ?

[Darryl Miles]

How do I do this with GCC 4 ?  This works with GCC3 on i386, but not on 
GCC4 on x86_64.  Any advise on what #ifdef to put in place or if there 
is one way that works with both GCC versions ?

 From the output of GCC test.c => test.s

#APP

        pushfl
        popl %eax

#NO_APP

Yeilds errors on GCC4 x86_64:

test.s:2287: Error: suffix or operands invalid for `pushf'
test.s:2288: Error: suffix or operands invalid for `pop'


Thanks

Darryl

Re: GCC4 x86_64 pushfl / pop %eax inline asm ?

[Ian Lance Taylor]

Darryl Miles <darryl-mailinglists@netbauds.net> writes:

> How do I do this with GCC 4 ?  This works with GCC3 on i386, but not
> on GCC4 on x86_64.  Any advise on what #ifdef to put in place or if
> there is one way that works with both GCC versions ?
> 
>  From the output of GCC test.c => test.s
> 
> #APP
> 
>         pushfl
>         popl %eax
> 
> #NO_APP
> 
> Yeilds errors on GCC4 x86_64:
> 
> test.s:2287: Error: suffix or operands invalid for `pushf'
> test.s:2288: Error: suffix or operands invalid for `pop'

Those errors are coming from the assembler.  This is an assembler
issue, not a gcc issue.

This one happens to be simple: the x86_64 does not have a pushfl
instruction.  Read the fine manual.  The x86_64 does have a pushfq
instruction.

Ian

Re: GCC4 x86_64 pushfl / pop %eax inline asm ?

[Darryl Miles]

Ian Lance Taylor wrote:
> Darryl Miles <darryl-mailinglists@netbauds.net> writes:
> 
>> test.s:2287: Error: suffix or operands invalid for `pushf'
>> test.s:2288: Error: suffix or operands invalid for `pop'
> 
> Those errors are coming from the assembler.  This is an assembler
> issue, not a gcc issue.

Sorry yes, I meant assembler, hence the use of .s files.


> This one happens to be simple: the x86_64 does not have a pushfl
> instruction.  Read the fine manual.  The x86_64 does have a pushfq
> instruction.

Ah, I was not aware of that, I'm porting existing code and was expecting 
the same instructions to exist.  Thanks for his pointer I have now got 
my code to compile again for both targets.

Thanks for your help!

Darryl