[PATCH] D8705: ScheduleDAGInstrs::buildSchedGraph() handling of memory dependecies rewritten.

[Andrew Trick via llvm-commits]

atrick added a comment.

I think we need to be conservative in the event that mem_operands are missing, since we haven't made that guarantee--and that's a separate discussion. For example, non-aliasing operations might exist prior to register allocation to handle calling convention (I'm not sure if this is purely theoretical without running tests on all targets).

You can probably be just as aggressive when the instruction has mem_operands. You may just need to distinguish between a load/store without a single mem_operand vs. one without a reachable underlying object. i.e. if it the Store has a mem_operand and is known not to be a PseudoSourceValue, but has a null Value, then your implementation should still be fine.


http://reviews.llvm.org/D8705