https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65796
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2015-04-20 Ever confirmed|0 |1 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- There is some older bug where I noticed the same issue. It's basically an artifact of the x86 calling conventions and GCC going through generic argument setup code (and RTL optimizers not being able to optimize spill + load into unpcklps). That said, somebody needs to find the duplicate bugreport. PR48607 is also related.