------- Comment #1 from rguenth at gcc dot gnu dot org 2006-05-12 08:27 ------- f is marked addressable and assigned a stack slot. That the stores are not optimized away later is probably due to aliasing issues - an open-coded memcpy must behave like the -fno-strict-aliasing case, so I guess we applied measures to assure this and this prevents this optimization. 3.3 and 3.3-hammer can do the optimization.
-- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |rguenth at gcc dot gnu dot | |org, hubicka at gcc dot gnu | |dot org Status|UNCONFIRMED |NEW Component|other |rtl-optimization Ever Confirmed|0 |1 Keywords| |missed-optimization Known to fail| |3.4.6 4.0.3 4.1.0 4.2.0 Known to work| |3.3.6 Last reconfirmed|0000-00-00 00:00:00 |2006-05-12 08:27:14 date| | Summary|__builtin_memcpy generates |[4.0/4.1/4.2 Regression] |redundant stores/moves. |__builtin_memcpy generates | |redundant stores/moves. Target Milestone|--- |4.0.4 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27567