[Bug rtl-optimization/48774] [4.6/4.7 Regression] gcc-4.6.0 optimization regression on x86_64-unknown-linux-gnu

[xinliangli at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48774

davidxl <xinliangli at gmail dot com> changed:

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--- Comment #3 from davidxl <xinliangli at gmail dot com> 2011-04-27 19:04:12 UTC ---
(In reply to comment #2)
> It is caused by revision 162653:
> 
> http://gcc.gnu.org/ml/gcc-cvs/2010-07/msg01007.html


Looked at IVOPT transformation -- seems ok.

The program passes with the following options:


 -O2 -funroll-loops regression.c -fno-tree-vrp -fno-tree-dominator-opts
-fno-gcse

Removing any of the -fno-xxx options, the program fail. -fno-gcse makes
difference indicates tree level transformations are fine -- possibly bad
aliasing?

David