gcc-4.3 optimizer bugs?

Horst H. von Brand vonbrand at inf.utfsm.cl
Wed Feb 27 12:37:40 UTC 2008


Neal Becker <ndbecker2 at gmail.com> wrote:
> We are trying to track down a numerical problem with unuran that occurs on
> gcc-4.3.  I know that gcc now has a very extensive test suite, and bugs are
> not common.  I'm just wondering, are others finding similar problems with
> gcc-4.3?

> We are working on preparing a bug report.  The symptoms are:
> 1) Problem disappears if -O0
> 2) Problem disappears if a printf is added

That probably means there is a problem with the memory layout (something
stomping on your variables?).
What hapens if you call any other function instead of printf?

Have you tried to look at the generated assembly?

> 3) valgrind is silent
-- 
Dr. Horst H. von Brand                   User #22616 counter.li.org
Departamento de Informatica                    Fono: +56 32 2654431
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