1 files changed, 19 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86InstrInfo.h b/llvm/lib/Target/X86/X86InstrInfo.h
index a891af566d8..f5c7c3855fc 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.h
+++ b/llvm/lib/Target/X86/X86InstrInfo.h
@@ -586,6 +586,25 @@ private:
   /// operand and follow operands form a reference to the stack frame.
   bool isFrameOperand(const MachineInstr &MI, unsigned int Op,
                       int &FrameIndex) const;
+
+  /// Returns true iff the routine could find two commutable operands in the
+  /// given machine instruction with 3 vector inputs.
+  /// The 'SrcOpIdx1' and 'SrcOpIdx2' are INPUT and OUTPUT arguments. Their
+  /// input values can be re-defined in this method only if the input values
+  /// are not pre-defined, which is designated by the special value
+  /// 'CommuteAnyOperandIndex' assigned to it.
+  /// If both of indices are pre-defined and refer to some operands, then the
+  /// method simply returns true if the corresponding operands are commutable
+  /// and returns false otherwise.
+  ///
+  /// For example, calling this method this way:
+  ///     unsigned Op1 = 1, Op2 = CommuteAnyOperandIndex;
+  ///     findThreeSrcCommutedOpIndices(MI, Op1, Op2);
+  /// can be interpreted as a query asking to find an operand that would be
+  /// commutable with the operand#1.
+  bool findThreeSrcCommutedOpIndices(const MachineInstr &MI,
+                                     unsigned &SrcOpIdx1,
+                                     unsigned &SrcOpIdx2) const;
 };
 
 } // End llvm namespace