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Re: SIMPLE: A language-independent tree IR
Richard Henderson wrote:
> Yes, we must do something special to represent this. Otherwise
> we can't tell the difference between
>
> Z = A + B + C + D
> Z = ((A + B) + C) + D
>
> and, given a pipelined fpu, clearly you want the former rendered as
>
> t1 = A + B
> t2 = C + D
> Z = t1 + t2
Ah, yes - I see. The obvious way to parse both expressions would be
t1 = A + B
t2 = t1 + C
Z = t2 + D
while there _is_ a reordering difference between the two.
Still, I feel this is different from the "sequence point" concept of the
C language, but I cannot come up with a simple example that shows it.
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