------- Comment #12 from matz at gcc dot gnu dot org 2010-06-10 12:26 ------- I don't think it ever was intended that 'm' includes operands with embedded side-effects. I don't think so because making this work reliably is relatively difficult. In particular the tests that Jakub mentions would need implementation (and probably other changes too), and the point is that such things never were implemented. Hence with enough work it's probably possible to construct testcases also for much older versions of GCC that fail in similar ways.
If that means to slightly change the definition of 'm' compared to what is documented currently, well, so be it. The other definition is unreliable anyway, so any inline asm that uses 'm' and expects a side-effect is fishy at best. It is fishy because if the compiler forwards a side-effect into the operands it would have to rewrite the inline asm string to actually contain an instruction to calculate this side-effect, which obviously is bollocks. So, yes, auto-inc-dec should of course _not_ push side-effects into inline asm. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44492
