[DAG] Add m_SelectCCLike matcher for SELECT_CC and SELECT(SETCC(...))-2

Author: houngkoungting

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -4099,18 +4099,17 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
   // (sub x, ([v]select (uge x, y), y, 0)) -> (umin x, (sub x, y))
   if (N1.hasOneUse() && hasUMin(VT)) {
     SDValue Y;
-    if (sd_match(N1, m_SelectCCLike(m_Specific(N0), m_Value(Y), m_Zero(),
-                                    m_Deferred(Y),
-                                    m_SpecificCondCode(ISD::SETULT))) ||
-        sd_match(N1,
-                 m_SelectCCLike(m_Specific(N0), m_Value(Y), m_Deferred(Y),
-                                m_Zero(), m_SpecificCondCode(ISD::SETUGE))) ||
-        sd_match(N1, m_VSelect(m_SetCC(m_Specific(N0), m_Value(Y),
-                                       m_SpecificCondCode(ISD::SETULT)),
-                               m_Zero(), m_Deferred(Y))) ||
-        sd_match(N1, m_VSelect(m_SetCC(m_Specific(N0), m_Value(Y),
-                                       m_SpecificCondCode(ISD::SETUGE)),
-                               m_Deferred(Y), m_Zero())))
+    auto MS0 = m_Specific(N0);
+    auto MVY = m_Value(Y);
+    auto MZ = m_Zero();
+    auto MCC1 = m_SpecificCondCode(ISD::SETULT);
+    auto MCC2 = m_SpecificCondCode(ISD::SETUGE);
+
+    if (sd_match(N1, m_SelectCCLike(MS0, MVY, MZ, m_Deferred(Y), MCC1)) ||
+        sd_match(N1, m_SelectCCLike(MS0, MVY, m_Deferred(Y), MZ, MCC2)) ||
+        sd_match(N1, m_VSelect(m_SetCC(MS0, MVY, MCC1), MZ, m_Deferred(Y))) ||
+        sd_match(N1, m_VSelect(m_SetCC(MS0, MVY, MCC2), m_Deferred(Y), MZ)))
+
       return DAG.getNode(ISD::UMIN, DL, VT, N0,
                          DAG.getNode(ISD::SUB, DL, VT, N0, Y));
   }

llvm/unittests/CodeGen/SelectionDAGPatternMatchTest.cpp

@@ -961,23 +961,9 @@ TEST_F(SelectionDAGPatternMatchTest, MatchSelectCCLike) {
                                 TVal, FVal, DAG->getCondCode(ISD::SETLT));
 
   ISD::CondCode CC = ISD::SETLT;
-  auto Matcher =
-      m_SelectCCLike(m_Specific(LHS), m_Specific(RHS), m_Specific(TVal),
-                     m_Specific(FVal), m_CondCode(CC));
-
-  struct DAGMatchContext {
-    SelectionDAG &DAG;
-    DAGMatchContext(SelectionDAG &DAG) : DAG(DAG) {}
-
-    bool match(SDValue N, unsigned Opcode) const {
-      return N.getOpcode() == Opcode;
-    }
-
-    unsigned getNumOperands(SDValue N) const { return N.getNumOperands(); }
-  };
-
-  DAGMatchContext Ctx(*DAG);
-  EXPECT_TRUE(Matcher.match(Ctx, Select));
+  EXPECT_TRUE(sd_match(
+      Select, m_SelectCCLike(m_Specific(LHS), m_Specific(RHS), m_Specific(TVal),
+                             m_Specific(FVal), m_CondCode(CC))));
 }
 
 TEST_F(SelectionDAGPatternMatchTest, MatchSelectCC) {
@@ -991,20 +977,7 @@ TEST_F(SelectionDAGPatternMatchTest, MatchSelectCC) {
                                 TVal, FVal, DAG->getCondCode(ISD::SETLT));
 
   ISD::CondCode CC = ISD::SETLT;
-  auto Matcher = m_SelectCC(m_Specific(LHS), m_Specific(RHS), m_Specific(TVal),
-                            m_Specific(FVal), m_CondCode(CC));
-
-  struct DAGMatchContext {
-    SelectionDAG &DAG;
-    DAGMatchContext(SelectionDAG &DAG) : DAG(DAG) {}
-
-    bool match(SDValue N, unsigned Opcode) const {
-      return N.getOpcode() == Opcode;
-    }
-
-    unsigned getNumOperands(SDValue N) const { return N.getNumOperands(); }
-  };
-
-  DAGMatchContext Ctx(*DAG);
-  EXPECT_TRUE(Matcher.match(Ctx, Select));
+  EXPECT_TRUE(sd_match(Select, m_SelectCC(m_Specific(LHS), m_Specific(RHS),
+                                          m_Specific(TVal), m_Specific(FVal),
+                                          m_CondCode(CC))));
 }