[Bug inline-asm/63900] memory constrains needlessly doing memory clobber

amonakov at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Wed Oct 24 12:36:00 GMT 2018


Alexander Monakov <amonakov at gcc dot gnu.org> changed:

           What    |Removed                     |Added
                 CC|                            |amonakov at gcc dot gnu.org

--- Comment #10 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
No, as mentioned in comment 3 there aren't any "full memory clobbers" anywhere,
the title of the bug is inaccurate. The original testcase shows that under
specific circumstances RTL optimizations fail to clean up redundant loads; your
testcase does not reproduce those circumstances.

FWIW it's a technically missed-optimization for GIMPLE passes as well, GCC
could have cleaned this up without relying on RTL passes: PR 87728.

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