[Bug target/15184] [4.6/4.7/4.8 Regression] Direct access to byte inside word not working with -march=pentiumpro

steven at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Fri Nov 9 22:32:00 GMT 2012


Steven Bosscher <steven at gcc dot gnu.org> changed:

           What    |Removed                     |Added
           Priority|P5                          |P3
   Last reconfirmed|2005-05-28 18:17:13         |2012-11-09 18:17:13
                 CC|                            |steven at gcc dot gnu.org
      Known to fail|                            |

--- Comment #20 from Steven Bosscher <steven at gcc dot gnu.org> 2012-11-09 22:32:30 UTC ---
(In reply to comment #13)

This is indeed pretty bad. Works with GCC 4.1, fails with GCC 4.3 and
with current top-of-trunk, and for all i686 variants including relatively
new CPUs based on the P6 micro-architecture, like core2 and atom.

I disagree with comment #10, and I don't think this problem is minor.  The
code of the test case is common idiom that should be optimized properly.
Please can the RMs have a new look at this.

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