Revert 97667. It broke a bunch of tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97673 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 63 insertions, 0 deletions

diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp
index 713aef0d8b..c5f555b02c 100644
--- a/lib/CodeGen/MachineCSE.cpp
+++ b/lib/CodeGen/MachineCSE.cpp
@@ -28,6 +28,69 @@ using namespace llvm;
 STATISTIC(NumCoalesces, "Number of copies coalesced");
 STATISTIC(NumCSEs,      "Number of common subexpression eliminated");
 
+namespace llvm {
+  template<> struct DenseMapInfo<MachineInstr*> {
+    static inline MachineInstr *getEmptyKey() {
+      return 0;
+    }
+
+    static inline MachineInstr *getTombstoneKey() {
+      return reinterpret_cast<MachineInstr*>(-1);
+    }
+
+    static unsigned getHashValue(const MachineInstr* const &MI) {
+      unsigned Hash = MI->getOpcode() * 37;
+      for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+        const MachineOperand &MO = MI->getOperand(i);
+        uint64_t Key = (uint64_t)MO.getType() << 32;
+        switch (MO.getType()) {
+        default: break;
+        case MachineOperand::MO_Register:
+          if (MO.isDef() && TargetRegisterInfo::isVirtualRegister(MO.getReg()))
+            continue;  // Skip virtual register defs.
+          Key |= MO.getReg();
+          break;
+        case MachineOperand::MO_Immediate:
+          Key |= MO.getImm();
+          break;
+        case MachineOperand::MO_FrameIndex:
+        case MachineOperand::MO_ConstantPoolIndex:
+        case MachineOperand::MO_JumpTableIndex:
+          Key |= MO.getIndex();
+          break;
+        case MachineOperand::MO_MachineBasicBlock:
+          Key |= DenseMapInfo<void*>::getHashValue(MO.getMBB());
+          break;
+        case MachineOperand::MO_GlobalAddress:
+          Key |= DenseMapInfo<void*>::getHashValue(MO.getGlobal());
+          break;
+        case MachineOperand::MO_BlockAddress:
+          Key |= DenseMapInfo<void*>::getHashValue(MO.getBlockAddress());
+          break;
+        }
+        Key += ~(Key << 32);
+        Key ^= (Key >> 22);
+        Key += ~(Key << 13);
+        Key ^= (Key >> 8);
+        Key += (Key << 3);
+        Key ^= (Key >> 15);
+        Key += ~(Key << 27);
+        Key ^= (Key >> 31);
+        Hash = (unsigned)Key + Hash * 37;
+      }
+      return Hash;
+    }
+
+    static bool isEqual(const MachineInstr* const &LHS,
+                        const MachineInstr* const &RHS) {
+      if (RHS == getEmptyKey() || RHS == getTombstoneKey() ||
+          LHS == getEmptyKey() || LHS == getTombstoneKey())
+        return LHS == RHS;
+      return LHS->isIdenticalTo(RHS, MachineInstr::IgnoreVRegDefs);
+    }
+  };
+} // end llvm namespace
+
 namespace {
   class MachineCSE : public MachineFunctionPass {
     const TargetInstrInfo *TII;