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Re: Defining constraint for registers tuple
Kirill Yukhin <firstname.lastname@example.org> writes:
> I'm working on implementation of `mulx` (which is part of BMI2). One
> of improvements compared generic `mul` is that it allows to specify
> destination registers.
> For `mul` we have `A` constraint, which stands for AX:DX pair.
> So, is there a possibility to relax such cinstraint and allow any pair
> of registers as destination?
Don't change the constraint, just add an alternative. Or use a
different insn with an insn predicate.