On Mon, Aug 8, 2011 at 4:19 PM, Vladimir Makarov <vmaka...@redhat.com> wrote: > The following patch fixes PR49990. The problem is described on > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49936 > > Reg classes which can not change modes for some pseudo were excluded from > the consideration. As I wrote recently, they should not. Instead the > correct cost for changing mode (by moving through memory or other class > register) should be taken into the account. I believe the cost is already > calculated rightly for this case, fortunately. > > The patch was successfully bootstrapped on x86-64 and ppc64. Actually I did > not find a difference in generated code on variety tests on x86/x86-64 and > arm (that is what I tried). > > Committed as rev. 177575. > > > > 2011-08-08 Vladimir Makarov <vmaka...@redhat.com> > > PR rtl-optimization/49990 > * ira-costs.c (print_allocno_costs, print_pseudo_costs): Don't > ignore classes which can not change mode. > (find_costs_and_classes): Ditto. > >
It breaks GCC on Linux/x86: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50026 -- H.J.
