g77 bug?
Toon Moene
toon@moene.indiv.nluug.nl
Fri Nov 1 14:27:00 GMT 2002
Jean-Pierre.Eckmann@physics.unige.ch wrote:
> This seems to be an optimization bug in g77/gcc
>
> With Optimization <= O1 (only on file escape.f) the program gives
> different results from optimizing O2
This sounds like the known problem that, on ix86 processors, sometimes
increasing optimisation levels will result in more variables being kept
in (80-bit) floating point registers, which will yield different
rounding after operations and different results.
On my powerpc-unknown-linux-gnu system, compilations with g77 -O0
escape.f and g77 -O2 escape.f give identical results.
Kind regards,
--
Toon Moene - mailto:toon@moene.indiv.nluug.nl - phoneto: +31 346 214290
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