Improve MachineMemOperand handling.

- Allocate MachineMemOperands and MachineMemOperand lists in MachineFunctions.
   This eliminates MachineInstr's std::list member and allows the data to be
   created by isel and live for the remainder of codegen, avoiding a lot of
   copying and unnecessary translation. This also shrinks MemSDNode.
 - Delete MemOperandSDNode. Introduce MachineSDNode which has dedicated
   fields for MachineMemOperands.
 - Change MemSDNode to have a MachineMemOperand member instead of its own
   fields with the same information. This introduces some redundancy, but
   it's more consistent with what MachineInstr will eventually want.
 - Ignore alignment when searching for redundant loads for CSE, but remember
   the greatest alignment.

Target-specific code which previously used MemOperandSDNodes with generic
SDNodes now use MemIntrinsicSDNodes, with opcodes in a designated range
so that the SelectionDAG framework knows that MachineMemOperand information
is available.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82794 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MachineFunction.cpp

@@ -190,11 +190,6 @@ MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
 ///
 void
 MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
-  // Clear the instructions memoperands. This must be done manually because
-  // the instruction's parent pointer is now null, so it can't properly
-  // deallocate them on its own.
-  MI->clearMemOperands(*this);
-
   MI->~MachineInstr();
   InstructionRecycler.Deallocate(Allocator, MI);
 }
@@ -217,6 +212,29 @@ MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
   BasicBlockRecycler.Deallocate(Allocator, MBB);
 }
 
+MachineMemOperand *
+MachineFunction::getMachineMemOperand(const Value *v, unsigned f,
+                                      int64_t o, uint64_t s,
+                                      unsigned base_alignment) {
+  return new (Allocator.Allocate<MachineMemOperand>())
+             MachineMemOperand(v, f, o, s, base_alignment);
+}
+
+MachineMemOperand *
+MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
+                                      int64_t Offset, uint64_t Size) {
+  return new (Allocator.Allocate<MachineMemOperand>())
+             MachineMemOperand(MMO->getValue(), MMO->getFlags(),
+                               int64_t(uint64_t(MMO->getOffset()) +
+                                       uint64_t(Offset)),
+                               Size, MMO->getBaseAlignment());
+}
+
+MachineInstr::mmo_iterator
+MachineFunction::allocateMemRefsArray(unsigned long Num) {
+  return Allocator.Allocate<MachineMemOperand *>(Num);
+}
+
 void MachineFunction::dump() const {
   print(errs());
 }