Re: 100x perfomance regression between gcc 3.4.5 and gcc 4.X

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

"Richard Guenther" <richard.guenther@gmail.com> writes:

[...]

| this one should be measured.  But note that the benchmark is a
| no-op and can be validly optimizes to int main() { return 0; } by the
| compiler.  This is why I call it a stupid benchmark.

please let's refrain from getting into that back hole.  

Different people measure different things that they perceive important
for them.  I doubt that the "optimization to int main() { return 0; }"
would be useful to everybody.

| Also you are measuring exclusively cache performance.

that may be a decisive criteria under given circumstances; it takes
more justification to qualify it as "stupid benchmark".  We can either
acknowledge "oops, we fumbled that case; but we are not going to fix
it" or "well, we should not have done that; it should be fixed".  
But handwaving with "stupid" qualification is not helpful.

-- Gaby