gcc-4.3 optimizer bugs?

Neal Becker ndbecker2 at gmail.com
Wed Feb 27 11:25:36 UTC 2008


Jakub Jelinek wrote:

> If it is on i?86, might very well be a problem caused by excess precision.
> Try -O2 -msse2 -mfpmath=sse to see if it helps, you likely need some
> volatile temporaries to ensure results are rounded down to the desired
> float resp. double precision (when results are kept within FP stack, they
> use extended precision).
> If not, using binary search between -O0 and -O2 objects you can easily
> find the problematic object and with some extra effort even the
> problematic function.  Create a self-contained testcase from it (main
> calling the problematic function with some arguments that reproduce it (if
> needed make it __attribute__((noinline)), add stubs for functions the
> problematic function calls) and report.
> 
> Jakub

x86_64.  I guess that's the same?




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