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RE: SSA code debugging
On Tue, 2004-08-10 at 09:58, Diego Novillo wrote:
> On Tue, 2004-08-10 at 09:43, Flynn, Lori Arline (Lori) wrote:
>
> > So if there are two versions of 'int A' by the SSA step, A_1 and A_2:
> > I could find out A_1 is at 0x63e4 and A_2 is 0x6350.
> >
> Ah, OK. No, that is not possible. SSA names do not (necessarily)
> correspond to real variables in the generated code. All the different
> names for variable 'A' tend to be collapsed to the same object in the
> generated code.
>
> Once the SSA transformations are finished, the program is rewritten back
> into normal form. Only in cases where two SSA names for the same
> variable have overlapping live ranges, will the compiler generate other
> variables for each name. Otherwise, all the names for a symbol 'X' are
> collapsed back to 'X'.
>
If there are distinct live ranges for a variable, we give each live
range different names as well.
Andrew.