http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10474
--- Comment #19 from Martin Jambor <jamborm at gcc dot gnu.org> --- (In reply to Ryan Johnson from comment #18) > Great! Does this mean shrink-wrapping will be in gcc-4.9, at least for > x86_64 and ppc64? Well, a fairly basic (but not altogether unreasonable) shrink-wrapping "was" in gcc 4.8 (and earlier versions) too and that has not changed at all. The problem with this and similar testcases was that the register allocator made decisions which made shrink-wrapping impossible (or at least too difficult to perform). The change I committed and which will be a part of gcc 4.9 fixes this for a class of pseudo-registers which commonly result in this problem but other cases will still remain unresolved, for example PR 51982. For some statistics about what impact the implemented technique has, see the email accompanying the first submission of the patch: http://gcc.gnu.org/ml/gcc-patches/2013-10/msg01719.html If you find another similar example which is important and clearly possible to shrink-wrap but we don't do it, feel free to submit a new missed-optimization bug and CC me.
