I wrote:
> I still dare to doubt whether you've tested this, because AFAICS
> the operand numbering is wrong. The "r"(lock) operand is number 3
> given these operand declarations, not number 2.
Oh, my apologies, scratch that. Evidently I put in the "+m"(*lock)
operand and confused myself about what was what.
I still think the form I proposed is better style though.
regards, tom lane