http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59535
Vladimir Makarov <vmakarov at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |vmakarov at gcc dot gnu.org --- Comment #9 from Vladimir Makarov <vmakarov at gcc dot gnu.org> --- (In reply to Richard Earnshaw from comment #5) > Number of register-register move operations in the testcase > lra: 208 > no-lra: 105 That is huge degradation. And I guess it is not only because of 2-ops insns. It works adequate on x86/x86-64. Although I know some issues with 2-ops commutative insns (I am trying to fix it too). I think major problem is in wrong alternative choices as thumb lo/hi reg usage is complicated. I take this bug very seriously. If I cannot fix it till end of Jan (sorry, it is a vacation time), probably we should switch to reload pass for thumb.