[llvm] [ConstraintElim] Extend `checkOrAndOpImpliedByOther` to handle and/or expr trees. (PR #117123)

[Nikita Popov via llvm-commits]

================
@@ -1511,22 +1508,41 @@ static bool checkOrAndOpImpliedByOther(
   if (OtherOpIdx != 0 && isa<SelectInst>(JoinOp))
     return false;
 
-  if (!match(JoinOp->getOperand(OtherOpIdx),
-             m_ICmp(Pred, m_Value(A), m_Value(B))))
-    return false;
-
-  // For OR, check if the negated condition implies CmpToCheck.
-  bool IsOr = match(JoinOp, m_LogicalOr());
-  if (IsOr)
-    Pred = CmpInst::getInversePredicate(Pred);
-
-  // Optimistically add fact from first condition.
   unsigned OldSize = DFSInStack.size();
-  Info.addFact(Pred, A, B, CB.NumIn, CB.NumOut, DFSInStack);
+  auto InfoRestorer = make_scope_exit([&]() {
+    // Remove entries again.
+    while (OldSize < DFSInStack.size()) {
+      StackEntry E = DFSInStack.back();
+      removeEntryFromStack(E, Info, ReproducerModule, ReproducerCondStack,
+                           DFSInStack);
+    }
+  });
+  bool IsOr = match(JoinOp, m_LogicalOr());
+  SmallVector<Value *, 4> Worklist({JoinOp->getOperand(OtherOpIdx)});
+  // Do a traversal of the AND/OR tree to add facts from leaf compares.
+  while (!Worklist.empty()) {
+    Value *Val = Worklist.pop_back_val();
+    Value *LHS, *RHS;
+    ICmpInst::Predicate Pred;
+    if (match(Val, m_ICmp(Pred, m_Value(LHS), m_Value(RHS)))) {
+      // For OR, check if the negated condition implies CmpToCheck.
+      if (IsOr)
+        Pred = CmpInst::getInversePredicate(Pred);
+      // Optimistically add fact from the other compares in the AND/OR.
+      Info.addFact(Pred, LHS, RHS, CB.NumIn, CB.NumOut, DFSInStack);
+      continue;
+    }
+    if (IsOr ? match(Val, m_LogicalOr(m_Value(LHS), m_Value(RHS)))
+             : match(Val, m_LogicalAnd(m_Value(LHS), m_Value(RHS)))) {
+      Worklist.push_back(LHS);
+      Worklist.push_back(RHS);
+      continue;
+    }
+    return false;
----------------
nikic wrote:

Do you plan to adjust this in this PR or a followup?

https://github.com/llvm/llvm-project/pull/117123