first changes for ValueTrackingTest.cpp and SelectionDAG for s/ucmp

Author: miguelraz

llvm/include/llvm/CodeGen/ISDOpcodes.h

@@ -676,6 +676,11 @@ enum NodeType {
   UMIN,
   UMAX,
 
+  /// [US]CMP - Three way integer comparison - returns -1, 0, or 1 if
+  /// Op1 < Op2, Op1 == Op2, Op1 > Op2, respectively.
+  SCMP,
+  UCMP,
+
   /// Bitwise operators - logical and, logical or, logical xor.
   AND,
   OR,

llvm/include/llvm/CodeGen/TargetLowering.h

@@ -5314,6 +5314,10 @@ class TargetLowering : public TargetLoweringBase {
   /// method accepts integers as its arguments.
   SDValue expandIntMINMAX(SDNode *Node, SelectionDAG &DAG) const;
 
+  /// Method for building the DAG expansion of ISD::[US]CMP. This
+  /// method accepts integers as its arguments.
+  SDValue expandCMP(SDNode *Node, SelectionDAG &DAG) const;
+
   /// Method for building the DAG expansion of ISD::[US][ADD|SUB]SAT. This
   /// method accepts integers as its arguments.
   SDValue expandAddSubSat(SDNode *Node, SelectionDAG &DAG) const;

llvm/unittests/Analysis/ValueTrackingTest.cpp

@@ -891,6 +891,8 @@ TEST(ValueTracking, propagatesPoison) {
       {true, "call i32 @llvm.smin.i32(i32 %x, i32 %y)", 0},
       {true, "call i32 @llvm.umax.i32(i32 %x, i32 %y)", 0},
       {true, "call i32 @llvm.umin.i32(i32 %x, i32 %y)", 0},
+      {true, "call i32 @llvm.scmp.i32(i32 %x, i32 %y)", 0},
+      {true, "call i32 @llvm.ucmp.i32(i32 %x, i32 %y)", 0},
       {true, "call i32 @llvm.bitreverse.i32(i32 %x)", 0},
       {true, "call i32 @llvm.bswap.i32(i32 %x)", 0},
       {false, "call i32 @llvm.fshl.i32(i32 %x, i32 %y, i32 %shamt)", 0},