DAG: Handle poison in m_Undef

[arsenm]

No description provided.

[arsenm]

• DAG: Handle poison in m_Undef #168288 👈 (View in Graphite)
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[llvmbot]

@llvm/pr-subscribers-llvm-selectiondag

Author: Matt Arsenault (arsenm)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/168288.diff

1 Files Affected:

• (modified) llvm/include/llvm/CodeGen/SDPatternMatch.h (+68-66)

diff --git a/llvm/include/llvm/CodeGen/SDPatternMatch.h b/llvm/include/llvm/CodeGen/SDPatternMatch.h
index 511cb56f73dcb..3c8d46aea505c 100644
--- a/llvm/include/llvm/CodeGen/SDPatternMatch.h
+++ b/llvm/include/llvm/CodeGen/SDPatternMatch.h
@@ -155,9 +155,76 @@ struct Opcode_match {
   }
 };
 
+// === Patterns combinators ===
+template <typename... Preds> struct And {
+  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
+    return true;
+  }
+};
+
+template <typename Pred, typename... Preds>
+struct And<Pred, Preds...> : And<Preds...> {
+  Pred P;
+  And(const Pred &p, const Preds &...preds) : And<Preds...>(preds...), P(p) {}
+
+  template <typename MatchContext>
+  bool match(const MatchContext &Ctx, SDValue N) {
+    return P.match(Ctx, N) && And<Preds...>::match(Ctx, N);
+  }
+};
+
+template <typename... Preds> struct Or {
+  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
+    return false;
+  }
+};
+
+template <typename Pred, typename... Preds>
+struct Or<Pred, Preds...> : Or<Preds...> {
+  Pred P;
+  Or(const Pred &p, const Preds &...preds) : Or<Preds...>(preds...), P(p) {}
+
+  template <typename MatchContext>
+  bool match(const MatchContext &Ctx, SDValue N) {
+    return P.match(Ctx, N) || Or<Preds...>::match(Ctx, N);
+  }
+};
+
+template <typename Pred> struct Not {
+  Pred P;
+
+  explicit Not(const Pred &P) : P(P) {}
+
+  template <typename MatchContext>
+  bool match(const MatchContext &Ctx, SDValue N) {
+    return !P.match(Ctx, N);
+  }
+};
+// Explicit deduction guide.
+template <typename Pred> Not(const Pred &P) -> Not<Pred>;
+
+/// Match if the inner pattern does NOT match.
+template <typename Pred> inline Not<Pred> m_Unless(const Pred &P) {
+  return Not{P};
+}
+
+template <typename... Preds> And<Preds...> m_AllOf(const Preds &...preds) {
+  return And<Preds...>(preds...);
+}
+
+template <typename... Preds> Or<Preds...> m_AnyOf(const Preds &...preds) {
+  return Or<Preds...>(preds...);
+}
+
+template <typename... Preds> auto m_NoneOf(const Preds &...preds) {
+  return m_Unless(m_AnyOf(preds...));
+}
+
 inline Opcode_match m_Opc(unsigned Opcode) { return Opcode_match(Opcode); }
 
-inline Opcode_match m_Undef() { return Opcode_match(ISD::UNDEF); }
+template <typename... Preds> auto m_Undef() {
+  return m_AnyOf(Opcode_match(ISD::UNDEF), Opcode_match(ISD::POISON));
+}
 
 inline Opcode_match m_Poison() { return Opcode_match(ISD::POISON); }
 
@@ -373,71 +440,6 @@ template <typename Pattern> inline auto m_LegalType(const Pattern &P) {
                         P};
 }
 
-// === Patterns combinators ===
-template <typename... Preds> struct And {
-  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
-    return true;
-  }
-};
-
-template <typename Pred, typename... Preds>
-struct And<Pred, Preds...> : And<Preds...> {
-  Pred P;
-  And(const Pred &p, const Preds &...preds) : And<Preds...>(preds...), P(p) {}
-
-  template <typename MatchContext>
-  bool match(const MatchContext &Ctx, SDValue N) {
-    return P.match(Ctx, N) && And<Preds...>::match(Ctx, N);
-  }
-};
-
-template <typename... Preds> struct Or {
-  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
-    return false;
-  }
-};
-
-template <typename Pred, typename... Preds>
-struct Or<Pred, Preds...> : Or<Preds...> {
-  Pred P;
-  Or(const Pred &p, const Preds &...preds) : Or<Preds...>(preds...), P(p) {}
-
-  template <typename MatchContext>
-  bool match(const MatchContext &Ctx, SDValue N) {
-    return P.match(Ctx, N) || Or<Preds...>::match(Ctx, N);
-  }
-};
-
-template <typename Pred> struct Not {
-  Pred P;
-
-  explicit Not(const Pred &P) : P(P) {}
-
-  template <typename MatchContext>
-  bool match(const MatchContext &Ctx, SDValue N) {
-    return !P.match(Ctx, N);
-  }
-};
-// Explicit deduction guide.
-template <typename Pred> Not(const Pred &P) -> Not<Pred>;
-
-/// Match if the inner pattern does NOT match.
-template <typename Pred> inline Not<Pred> m_Unless(const Pred &P) {
-  return Not{P};
-}
-
-template <typename... Preds> And<Preds...> m_AllOf(const Preds &...preds) {
-  return And<Preds...>(preds...);
-}
-
-template <typename... Preds> Or<Preds...> m_AnyOf(const Preds &...preds) {
-  return Or<Preds...>(preds...);
-}
-
-template <typename... Preds> auto m_NoneOf(const Preds &...preds) {
-  return m_Unless(m_AnyOf(preds...));
-}
-
 // === Generic node matching ===
 template <unsigned OpIdx, typename... OpndPreds> struct Operands_match {
   template <typename MatchContext>

[RKSimon]

please can you pre-commit the NFC reordering to minimize the diff in actual feature change

[github-actions]

🐧 Linux x64 Test Results

• 186454 tests passed
• 4869 tests skipped

[mshockwave]

unused template <typename... Preds>

[mshockwave]

2025-11-21T18:37:06.9642153Z ld.lld: error: duplicate symbol: llvm::SDPatternMatch::m_Undef()
2025-11-21T18:37:06.9642788Z >>> defined at SDPatternMatch.h:225 (/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/include/llvm/CodeGen/SDPatternMatch.h:225)
2025-11-21T18:37:06.9643531Z >>> AArch64ISelLowering.cpp.o:(llvm::SDPatternMatch::m_Undef()) in archive lib/libLLVMAArch64CodeGen.a
2025-11-21T18:37:06.9644294Z >>> defined at SDPatternMatch.h:225 (/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/include/llvm/CodeGen/SDPatternMatch.h:225)
2025-11-21T18:37:06.9645161Z >>> SIISelLowering.cpp.o:(.text._ZN4llvm14SDPatternMatch7m_UndefEv+0x0) in archive lib/libLLVMAMDGPUCodeGen.a

I guess you need to add inline.

[mshockwave]

LGTM