tree-ssa performance (was: treelang fix for rs6000 / treelang not proper front end)

[Theodore Papadopoulo]

pfeifer@dbai.tuwien.ac.at said:
> This indicates that the SPEC tester is not sufficient wrt. to
> compile-time regressions. 

Let me make a guess:

    - Gerald, your test code is C++.
    - SPEC is mostly (if not all) C ?

It has been said many times on this list that the compiler behaviour 
is not the same for C and C++.

I bet that most of the slowdown reported is for C++, whereas most of 
the new code introduced in the compiled is tested for not introducing 
slowdowns against C code (ie SPEC+gcc itself).
 
Perhaps, (if the above guess is valid), it is the proper time to add
some specific C++ compile-time tests, and to start to measure the 
slowdowns also for C++.

Indeed, it will not have the same value as SPEC (because it will be 
unique to gcc), but in the meantime, it might help asserting the 
impact of the changes for the different langages.

	Theo.

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Theodore Papadopoulo
Email: Theodore.Papadopoulo@sophia.inria.fr Tel: (33) 04 92 38 76 01
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