http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57911
Richard Earnshaw <rearnsha at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |WAITING Last reconfirmed| |2013-07-23 Ever confirmed|0 |1 --- Comment #1 from Richard Earnshaw <rearnsha at gcc dot gnu.org> --- The ABI specifies *minimum* alignment constraints. It can never specify a maximum. Compilers are entitled to place objects on whatever boundaries they wish if they think it will lead to better results (better does not necessarily mean faster). Even when optimizing for size it can be the case that padding some objects up to word boundaries will lead to smaller code (-Os is primarily aimed at generating smaller code segments, not necessarily about minimizing stack usage). For example, it might allow LDM operations to be used to read multiple words from the object at once. If you have more details, then please supply pre-processed test case that we can look at.