Re: multiple assignment

mklarson@gte.net wrote:


> I have a testbed compiler for a simple C dialect (Renderman Shading
> Language). One of the problems I am having with evaluating the parse
> tree is with multiple assignement. It should be clean but it really is
> a hack for a recusive evaluator.
>
> a = b = c + 1
>
> [requires]
>
> pop b
> push b


You should implement a 'store' bytecode. Simple single assignments
would be compiled as 'store b' + 'pop top' (pop top is generated
by the semicolon) and then peephole-optimized to 'pop b'. If your
hack works for horrible C hacks as


          foo(a = b);


you can modify it to be a kind of 'in-place' peephole optimization.
So it would lose its hack status and become an elegant solution...


Paolo Bonzini

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