[SystemZ] Use CLC and IPM to implement memcmp

For now this is restricted to fixed-length comparisons with a length
in the range [1, 256], as for memcpy() and MVC.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188163 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 0 deletions

diff --git a/include/llvm/Target/TargetSelectionDAGInfo.h b/include/llvm/Target/TargetSelectionDAGInfo.h
index fe2fba42dc..35da1d7a73 100644
--- a/include/llvm/Target/TargetSelectionDAGInfo.h
+++ b/include/llvm/Target/TargetSelectionDAGInfo.h
@@ -94,6 +94,20 @@ public:
                           MachinePointerInfo DstPtrInfo) const {
     return SDValue();
   }
+
+  /// EmitTargetCodeForMemcmp - Emit target-specific code that performs a
+  /// memcmp, in cases where that is faster than a libcall.  The first
+  /// returned SDValue is the result of the memcmp and the second is
+  /// the chain.  Both SDValues can be null if a normal libcall should
+  /// be used.
+  virtual std::pair<SDValue, SDValue>
+  EmitTargetCodeForMemcmp(SelectionDAG &DAG, SDLoc dl,
+                          SDValue Chain,
+                          SDValue Op1, SDValue Op2,
+                          SDValue Op3, MachinePointerInfo Op1PtrInfo,
+                          MachinePointerInfo Op2PtrInfo) const {
+    return std::make_pair(SDValue(), SDValue());
+  }
 };
 
 } // end llvm namespace