http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55026
Eric Botcazou <ebotcazou at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2012-10-22 CC| |ebotcazou at gcc dot | |gnu.org Summary|[Multiple targets] |Useless stores generated |Inefficient code with |for structures passed by |structs passed by value |value Ever Confirmed|0 |1 Severity|normal |enhancement --- Comment #2 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2012-10-22 19:08:10 UTC --- This depends on the internal argument passing mechanism (BLKmode registers vs PARALLEL) and on the strict-alignment requirements of the architecture. Try: struct __attribute__((aligned (8))) foo { int a; int b; }; int f(struct foo x) { return x.a + x.b; } to watch the effects of the latter.