1 files changed, 28 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86InstrBuilder.h b/llvm/lib/Target/X86/X86InstrBuilder.h
index 787f15bc628..4ece035076d 100644
--- a/llvm/lib/Target/X86/X86InstrBuilder.h
+++ b/llvm/lib/Target/X86/X86InstrBuilder.h
@@ -83,6 +83,34 @@ struct X86AddressMode {
   }
 };
 
+/// Compute the addressing mode from an machine instruction starting with the
+/// given operand.
+static inline X86AddressMode getAddressFromInstr(MachineInstr *MI,
+                                                 unsigned Operand) {
+  X86AddressMode AM;
+  MachineOperand &Op = MI->getOperand(Operand);
+  if (Op.isReg()) {
+    AM.BaseType = X86AddressMode::RegBase;
+    AM.Base.Reg = Op.getReg();
+  } else {
+    AM.BaseType = X86AddressMode::FrameIndexBase;
+    AM.Base.FrameIndex = Op.getIndex();
+  }
+  Op = MI->getOperand(Operand + 1);
+  if (Op.isImm())
+    AM.Scale = Op.getImm();
+  Op = MI->getOperand(Operand + 2);
+  if (Op.isImm())
+    AM.IndexReg = Op.getImm();
+  Op = MI->getOperand(Operand + 3);
+  if (Op.isGlobal()) {
+    AM.GV = Op.getGlobal();
+  } else {
+    AM.Disp = Op.getImm();
+  }
+  return AM;
+}
+
 /// addDirectMem - This function is used to add a direct memory reference to the
 /// current instruction -- that is, a dereference of an address in a register,
 /// with no scale, index or displacement. An example is: DWORD PTR [EAX].