[Bug tree-optimization/62156] memcmp doesn't see through memcpy at compile-time

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62156

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-08-18
                 CC|                            |rguenth at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Hm, yeah.  Well, not sure if this is worth having a special case for in
tree-ssa-sccvn.c or in gimple_fold_stmt_to_constant_1.  I'd probably
try a simple pattern matching in gimple_fold_stmt_to_constant_1.

What kind of std::string code is this?  That is, can we expect
memcmp and memcpy to be adjacent (without intermediate memory operations?)