DAG: Handle poison in m_Undef

arsenm · arsenm · commit 35cbf2dbe1c8 · 2025-11-20T14:31:00.000-05:00
diff --git a/llvm/include/llvm/CodeGen/SDPatternMatch.h b/llvm/include/llvm/CodeGen/SDPatternMatch.h
@@ -222,7 +222,9 @@ template <typename... Preds> auto m_NoneOf(const Preds &...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); }
 
diff --git a/llvm/unittests/CodeGen/SelectionDAGPatternMatchTest.cpp b/llvm/unittests/CodeGen/SelectionDAGPatternMatchTest.cpp
@@ -551,6 +551,8 @@ TEST_F(SelectionDAGPatternMatchTest, matchConstants) {
   SDValue PoisonVInt32VT = DAG->getPOISON(VInt32VT);
   EXPECT_TRUE(sd_match(PoisonInt32VT, m_Poison()));
   EXPECT_TRUE(sd_match(PoisonVInt32VT, m_Poison()));
+  EXPECT_TRUE(sd_match(PoisonInt32VT, m_Undef()));
+  EXPECT_TRUE(sd_match(PoisonVInt32VT, m_Undef()));
 }
 
 TEST_F(SelectionDAGPatternMatchTest, patternCombinators) {

Original file line number	Diff line number	Diff line change
`@@ -551,6 +551,8 @@ TEST_F(SelectionDAGPatternMatchTest, matchConstants) {`
`551`	`551`	`SDValue PoisonVInt32VT = DAG->getPOISON(VInt32VT);`
`552`	`552`	`EXPECT_TRUE(sd_match(PoisonInt32VT, m_Poison()));`
`553`	`553`	`EXPECT_TRUE(sd_match(PoisonVInt32VT, m_Poison()));`
	`554`	`+ EXPECT_TRUE(sd_match(PoisonInt32VT, m_Undef()));`
	`555`	`+ EXPECT_TRUE(sd_match(PoisonVInt32VT, m_Undef()));`
`554`	`556`	`}`
`555`	`557`
`556`	`558`	`TEST_F(SelectionDAGPatternMatchTest, patternCombinators) {`