On Thu, Sep 10, 2020 at 03:31:53PM +0000, David Laight wrote:

quoted

quoted

	asm volatile ("" : "+r" (eax));
	// So here eax must contain the value set by the "xxxxx" instructions.

No, the register eax will contain the value of the eax variable.  In the
asm; it might well be there before or after the asm as well, but none of
that is guaranteed.

Perhaps not 'guaranteed', but very unlikely to be wrong.
It doesn't give gcc much scope for not generating the desired code.

Wanna bet?  :-)

Correct is correct.  Anything else is not.


Segher