[llvm] Add m_SelectCCLike matcher to match SELECT_CC or SELECT with SETCC (PR #149646)

[Simon Pilgrim via llvm-commits]

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@@ -578,6 +578,43 @@ m_InsertSubvector(const LHS &Base, const RHS &Sub, const IDX &Idx) {
   return TernaryOpc_match<LHS, RHS, IDX>(ISD::INSERT_SUBVECTOR, Base, Sub, Idx);
 }
 
+template <typename LTy, typename RTy, typename TTy, typename FTy, typename CCTy>
+struct SelectCC_match {
+  LTy L;
+  RTy R;
+  TTy T;
+  FTy F;
+  CCTy CC;
+
+  SelectCC_match(LTy L, RTy R, TTy T, FTy F, CCTy CC)
+      : L(std::move(L)), R(std::move(R)), T(std::move(T)), F(std::move(F)),
+        CC(std::move(CC)) {}
+
+  template <typename MatchContext>
+  bool match(MatchContext &Ctx, SDValue V) {
+    return V.getOpcode() == ISD::SELECT_CC && L.match(Ctx, V.getOperand(0)) &&
+           R.match(Ctx, V.getOperand(1)) && T.match(Ctx, V.getOperand(2)) &&
+           F.match(Ctx, V.getOperand(3)) && CC.match(Ctx, V.getOperand(4));
+  }
+};
+
+template <typename LTy, typename RTy, typename TTy, typename FTy, typename CCTy>
+inline auto m_SelectCC(LTy &&L, RTy &&R, TTy &&T, FTy &&F, CCTy &&CC) {
+  return SelectCC_match<std::decay_t<LTy>, std::decay_t<RTy>, std::decay_t<TTy>,
+                        std::decay_t<FTy>, std::decay_t<CCTy>>(
+      std::forward<LTy>(L), std::forward<RTy>(R), std::forward<TTy>(T),
+      std::forward<FTy>(F), std::forward<CCTy>(CC));
+}
+
+template <typename LTy, typename RTy, typename TTy, typename FTy, typename CCTy>
+inline auto m_SelectCCLike(LTy &&L, RTy &&R, TTy &&T, FTy &&F, CCTy &&CC) {
+  return SDPatternMatch::m_AnyOf(
+      SDPatternMatch::m_Select(SDPatternMatch::m_SetCC(L, R, CC), T, F),
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RKSimon wrote:

Why the namespace?

https://github.com/llvm/llvm-project/pull/149646