tree bdd2e29d59721787b1d6dd48c8dfca58ef4b49ce
parent 9c8148ac93835b7d53c81c554cde2e6da3730771
author Dan Gohman <gohman@apple.com> 1233283754 +0000
committer Dan Gohman <gohman@apple.com> 1233283754 +0000

Fix a post-RA scheduling dependency bug.

If a MachineInstr doesn't have a memoperand but has an opcode that
is known to load or store, assume its memory reference may alias
*anything*, including stack slots which the compiler completely
controls.

To partially compensate for this, teach the ScheduleDAG building
code to do basic getUnderlyingValue analysis. This greatly
reduces the number of instructions that require restrictive
dependencies. This code will need to be revisited when we start
doing real alias analysis, but it should suffice for now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63370 91177308-0d34-0410-b5e6-96231b3b80d8