Add m_SelectCCLike matcher to match SELECT_CC or SELECT with SETCC (#149646)
Fix #147282 and Follow-up to #148834
---------
Co-authored-by: Simon Pilgrim <llvm-dev@redking.me.uk>
diff --git a/llvm/include/llvm/CodeGen/SDPatternMatch.h b/llvm/include/llvm/CodeGen/SDPatternMatch.h
index 2967532..be90250 100644
--- a/llvm/include/llvm/CodeGen/SDPatternMatch.h
+++ b/llvm/include/llvm/CodeGen/SDPatternMatch.h
@@ -578,6 +578,18 @@
return TernaryOpc_match<LHS, RHS, IDX>(ISD::INSERT_SUBVECTOR, Base, Sub, Idx);
}
+template <typename LTy, typename RTy, typename TTy, typename FTy, typename CCTy>
+inline auto m_SelectCC(const LTy &L, const RTy &R, const TTy &T, const FTy &F,
+ const CCTy &CC) {
+ return m_Node(ISD::SELECT_CC, L, R, T, F, CC);
+}
+
+template <typename LTy, typename RTy, typename TTy, typename FTy, typename CCTy>
+inline auto m_SelectCCLike(const LTy &L, const RTy &R, const TTy &T,
+ const FTy &F, const CCTy &CC) {
+ return m_AnyOf(m_Select(m_SetCC(L, R, CC), T, F), m_SelectCC(L, R, T, F, CC));
+}
+
// === Binary operations ===
template <typename LHS_P, typename RHS_P, bool Commutable = false,
bool ExcludeChain = false>
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 6892751..daccf9a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4107,18 +4107,17 @@
// (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_Select(m_SetCC(m_Specific(N0), m_Value(Y),
- m_SpecificCondCode(ISD::SETULT)),
- m_Zero(), m_Deferred(Y))) ||
- sd_match(N1, m_Select(m_SetCC(m_Specific(N0), m_Value(Y),
- m_SpecificCondCode(ISD::SETUGE)),
- m_Deferred(Y), m_Zero())) ||
- 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));
}
diff --git a/llvm/unittests/CodeGen/SelectionDAGPatternMatchTest.cpp b/llvm/unittests/CodeGen/SelectionDAGPatternMatchTest.cpp
index 4e0bf38..16b9979 100644
--- a/llvm/unittests/CodeGen/SelectionDAGPatternMatchTest.cpp
+++ b/llvm/unittests/CodeGen/SelectionDAGPatternMatchTest.cpp
@@ -859,3 +859,35 @@
EXPECT_TRUE(sd_match(Vec, DAG.get(), m_AllOnes(true)));
}
}
+
+TEST_F(SelectionDAGPatternMatchTest, MatchSelectCCLike) {
+ using namespace SDPatternMatch;
+
+ SDValue LHS = DAG->getConstant(1, SDLoc(), MVT::i32);
+ SDValue RHS = DAG->getConstant(2, SDLoc(), MVT::i32);
+ SDValue TVal = DAG->getConstant(3, SDLoc(), MVT::i32);
+ SDValue FVal = DAG->getConstant(4, SDLoc(), MVT::i32);
+ SDValue Select = DAG->getNode(ISD::SELECT_CC, SDLoc(), MVT::i32, LHS, RHS,
+ TVal, FVal, DAG->getCondCode(ISD::SETLT));
+
+ ISD::CondCode CC = ISD::SETLT;
+ 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) {
+ using namespace SDPatternMatch;
+
+ SDValue LHS = DAG->getConstant(1, SDLoc(), MVT::i32);
+ SDValue RHS = DAG->getConstant(2, SDLoc(), MVT::i32);
+ SDValue TVal = DAG->getConstant(3, SDLoc(), MVT::i32);
+ SDValue FVal = DAG->getConstant(4, SDLoc(), MVT::i32);
+ SDValue Select = DAG->getNode(ISD::SELECT_CC, SDLoc(), MVT::i32, LHS, RHS,
+ TVal, FVal, DAG->getCondCode(ISD::SETLT));
+
+ ISD::CondCode CC = ISD::SETLT;
+ EXPECT_TRUE(sd_match(Select, m_SelectCC(m_Specific(LHS), m_Specific(RHS),
+ m_Specific(TVal), m_Specific(FVal),
+ m_CondCode(CC))));
+}
