1 files changed, 48 insertions, 0 deletions
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 77181cfcac3..a0284e6e153 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -6762,6 +6762,54 @@ ARMTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
     return BB;
   }
 
+  case ARM::MOVCCr:
+  case ARM::t2MOVCCr: {
+    // MOVCCr instructions can fold one of its operands as a predicated
+    // instruction:
+    //
+    //   %v1 = AND %v2, %v3
+    //   %v4 = MOVCCr %v5, %v1, CC
+    //
+    // Becomes:
+    //
+    //   %v4 = ANDCCrr %v5, %v2, %v3, CC
+    //
+    const MachineRegisterInfo &MRI = MI->getParent()->getParent()->getRegInfo();
+    MachineInstr *DefMI = 0;
+    unsigned Opc = canFoldARMInstrIntoMOVCC(MI->getOperand(2).getReg(),
+                                            DefMI, MRI);
+    bool Invert = !Opc;
+    if (!Opc)
+      Opc = canFoldARMInstrIntoMOVCC(MI->getOperand(1).getReg(), DefMI, MRI);
+    if (!Opc)
+      return BB;
+
+    // Create a new predicated version of DefMI.
+    // Rfalse is the first use.
+    MachineInstrBuilder NewMI = BuildMI(*BB, MI, dl, TII->get(Opc),
+                                        MI->getOperand(0).getReg())
+      .addOperand(MI->getOperand(Invert ? 2 : 1));
+
+    // Copy all the DefMI operands, excluding its (null) predicate.
+    const MCInstrDesc &DefDesc = DefMI->getDesc();
+    for (unsigned i = 1, e = DefDesc.getNumOperands();
+         i != e && !DefDesc.OpInfo[i].isPredicate(); ++i)
+      NewMI.addOperand(DefMI->getOperand(i));
+
+    unsigned CondCode = MI->getOperand(3).getImm();
+    if (Invert)
+      NewMI.addImm(ARMCC::getOppositeCondition(ARMCC::CondCodes(CondCode)));
+    else
+      NewMI.addImm(CondCode);
+    NewMI.addOperand(MI->getOperand(4));
+
+    AddDefaultCC(NewMI);
+
+    DefMI->eraseFromParent();
+    MI->eraseFromParent();
+    return BB;
+  }
+
   case ARM::BCCi64:
   case ARM::BCCZi64: {
     // If there is an unconditional branch to the other successor, remove it.