[Bug tree-optimization/35653] [4.3/4.4 Regression]: gcc-4.3 -O3/-ftree-vectorize regression: incorrect code generation

[edwintorok at gmail dot com]

------- Comment #8 from edwintorok at gmail dot com  2008-03-23 16:59 -------
(In reply to comment #7)
> Subject: Re:  [4.3/4.4 Regression]: gcc-4.3 -O3/-ftree-vectorize regression:
> incorrect code generation
> 
> This code violates c/c++ aliasing rules.
> 

-Wstrict-aliasing doesn't give a warning about it.

Accessing the memory as uint32_t is done for performance reasons, the
alternative would be to use byte-sized accesses. When reading, it would involve
additional shift/or instructions.

If the pointer is not aligned at 4 bytes, then uint32_t can't be done?

If that is the case, a warning would be *very* useful.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35653