[CodeGen] Refactor MachineMemOperand's Flags enum.

Summary:
- Give it a shorter name (because we're going to refer to it often from
  SelectionDAG and friends).

- Split the flags and alignment into separate variables.

- Specialize FlagsEnumTraits for it, so we can do bitwise ops on it
  without losing type information.

- Make some enum values constants in MachineMemOperand instead.
  MOMaxBits should not be a valid Flag.

- Simplify some of the bitwise ops for dealing with Flags.

Reviewers: chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D22281

llvm-svn: 275438

1 files changed, 8 insertions, 7 deletions

diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index 112e0ce3c92..3dbbd8780c3 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -497,13 +497,14 @@ MachinePointerInfo MachinePointerInfo::getStack(MachineFunction &MF,
   return MachinePointerInfo(MF.getPSVManager().getStack(), Offset);
 }
 
-MachineMemOperand::MachineMemOperand(MachinePointerInfo ptrinfo, unsigned f,
+MachineMemOperand::MachineMemOperand(MachinePointerInfo ptrinfo, Flags f,
                                      uint64_t s, unsigned int a,
                                      const AAMDNodes &AAInfo,
                                      const MDNode *Ranges)
-  : PtrInfo(ptrinfo), Size(s),
-    Flags((f & ((1 << MOMaxBits) - 1)) | ((Log2_32(a) + 1) << MOMaxBits)),
-    AAInfo(AAInfo), Ranges(Ranges) {
+    : PtrInfo(ptrinfo), Size(s), FlagVals(f), BaseAlignLog2(Log2_32(a) + 1),
+      AAInfo(AAInfo), Ranges(Ranges) {
+  assert(MOMaxFlag == (1 << MOMaxBits) - 1 &&
+         "MOMaxFlag and MOMaxBits have fallen out of sync.");
   assert((PtrInfo.V.isNull() || PtrInfo.V.is<const PseudoSourceValue*>() ||
           isa<PointerType>(PtrInfo.V.get<const Value*>()->getType())) &&
          "invalid pointer value");
@@ -517,7 +518,8 @@ void MachineMemOperand::Profile(FoldingSetNodeID &ID) const {
   ID.AddInteger(getOffset());
   ID.AddInteger(Size);
   ID.AddPointer(getOpaqueValue());
-  ID.AddInteger(Flags);
+  ID.AddInteger(getFlags());
+  ID.AddInteger(getBaseAlignment());
 }
 
 void MachineMemOperand::refineAlignment(const MachineMemOperand *MMO) {
@@ -528,8 +530,7 @@ void MachineMemOperand::refineAlignment(const MachineMemOperand *MMO) {
 
   if (MMO->getBaseAlignment() >= getBaseAlignment()) {
     // Update the alignment value.
-    Flags = (Flags & ((1 << MOMaxBits) - 1)) |
-      ((Log2_32(MMO->getBaseAlignment()) + 1) << MOMaxBits);
+    BaseAlignLog2 = Log2_32(MMO->getBaseAlignment()) + 1;
     // Also update the base and offset, because the new alignment may
     // not be applicable with the old ones.
     PtrInfo = MMO->PtrInfo;