[llvm] [DAG] SDPatternMatch - Fix m_Reassociatable mismatching (PR #170061)

[Min-Yih Hsu via llvm-commits]

================
@@ -842,6 +842,28 @@ TEST_F(SelectionDAGPatternMatchTest, matchReassociatableOp) {
   EXPECT_TRUE(sd_match(
       MUL, m_ReassociatableMul(m_Value(), m_Value(), m_Value(), m_Value())));
 
+  // (Op0 + Op1) + Op0 binds correctly, allowing commutation
+  SDValue ADD010 = DAG->getNode(ISD::ADD, DL, Int32VT, ADD01, Op0);
+  SDValue A, B;
+  EXPECT_TRUE(sd_match(
+      ADD010, m_ReassociatableAdd(m_Value(A), m_Value(B), m_Deferred(A))));
+  EXPECT_EQ(Op0, A);
+  EXPECT_EQ(Op1, B);
+  EXPECT_NE(A, B);
----------------
mshockwave wrote:

oh I originally thought GTest would just stop at the first failure, but now thinking it again I think you're right and GTest will  continue. I still think it's a bit redundant though.

https://github.com/llvm/llvm-project/pull/170061