1 files changed, 17 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp b/llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp
index 0f7a254075a..a38ff00ed41 100644
--- a/llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp
@@ -176,3 +176,20 @@ bool InstructionSelect::runOnMachineFunction(MachineFunction &MF) {
   // FIXME: Should we accurately track changes?
   return true;
 }
+
+bool InstructionSelector::isOperandImmEqual(
+    const MachineOperand &MO, int64_t Value,
+    const MachineRegisterInfo &MRI) const {
+  // TODO: We should also test isImm() and isCImm() too but this isn't required
+  //       until a DAGCombine equivalent is implemented.
+
+  if (MO.isReg()) {
+    MachineInstr *Def = MRI.getVRegDef(MO.getReg());
+    if (Def->getOpcode() != TargetOpcode::G_CONSTANT)
+      return false;
+    assert(Def->getOperand(1).isImm() && "G_CONSTANT values must be constants");
+    return Def->getOperand(1).getImm() == Value;
+  }
+
+  return false;
+}