Re: Inline Assembly, MOV, and Memory Operand Constraint

[Jeffrey Walton <noloader at gmail dot com>]

On Wed, Jun 15, 2011 at 5:27 AM, Georg-Johann Lay <avr@gjlay.de> wrote:
> Jeffrey Walton schrieb:
>> Hi All,
>>
>> I have a question on inline assembly. For my first experiment, I'm
>> trying to read the flags register. Intuitively, I'm trying to perform
>> the following:
>> ? ? mov %eax, result
>>
>> The assembler does not take the simple syntax (see [1], [2]), andI'm
>> having trouble getting the statement right. I've tried lots of
>> variations on the following, but have yet to find success.
>> ? ? unsigned int result;
>> ? ? ...
>> ? ? asm volatile("mov %eax, result" : "=m(result)");
>>
>> What's the trick to move from a register to memory (C variable)?
>
> Something like
>
> asm volatile("mov %%eax, %[result]" : [result] "=m" (result) :: "memory");
>
This also worked - thanks for the help.

Jeff