https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77687
--- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Tue Nov 29 05:29:47 2016 New Revision: 242949 URL: https://gcc.gnu.org/viewcvs?rev=242949&root=gcc&view=rev Log: rs6000: Make deallocation of a large frame work (PR77687) If we use ABI_V4 and we have a big stack frame, we end the epilogue with a "mr 1,11" (or similar) instruction. This instruction however has no dependencies on the earlier restores from stack (done via r11), so sched2 can end up reordering the insns, which is bad because we have no red zone so that you then restore from stack that is already deallocated. This fixes it by making that restore depend on the memory accesses. PR target/77687 * config/rs6000/rs6000.c (rs6000_emit_stack_reset): Emit the stack_restore_tie insn instead of stack_tie, for the SVR4 and SPE ABIs. * config/rs6000/rs6000.md (stack_restore_tie): New define_insn. Modified: trunk/gcc/ChangeLog trunk/gcc/config/rs6000/rs6000.c trunk/gcc/config/rs6000/rs6000.md
