1 files changed, 60 insertions, 15 deletions

diff --git a/contrib/llvm-project/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp b/contrib/llvm-project/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
index 18266ba07898..899d7e0a11e6 100644
--- a/contrib/llvm-project/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
+++ b/contrib/llvm-project/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
@@ -273,7 +273,16 @@ class ConstraintInfo {
 
 public:
   ConstraintInfo(const DataLayout &DL, ArrayRef<Value *> FunctionArgs)
-      : UnsignedCS(FunctionArgs), SignedCS(FunctionArgs), DL(DL) {}
+      : UnsignedCS(FunctionArgs), SignedCS(FunctionArgs), DL(DL) {
+    auto &Value2Index = getValue2Index(false);
+    // Add Arg > -1 constraints to unsigned system for all function arguments.
+    for (Value *Arg : FunctionArgs) {
+      ConstraintTy VarPos(SmallVector<int64_t, 8>(Value2Index.size() + 1, 0),
+                          false, false, false);
+      VarPos.Coefficients[Value2Index[Arg]] = -1;
+      UnsignedCS.addVariableRow(VarPos.Coefficients);
+    }
+  }
 
   DenseMap<Value *, unsigned> &getValue2Index(bool Signed) {
     return Signed ? SignedCS.getValue2Index() : UnsignedCS.getValue2Index();
@@ -1365,18 +1374,34 @@ removeEntryFromStack(const StackEntry &E, ConstraintInfo &Info,
     ReproducerCondStack.pop_back();
 }
 
-/// Check if the first condition for an AND implies the second.
-static bool checkAndSecondOpImpliedByFirst(
+/// Check if either the first condition of an AND or OR is implied by the
+/// (negated in case of OR) second condition or vice versa.
+static bool checkOrAndOpImpliedByOther(
     FactOrCheck &CB, ConstraintInfo &Info, Module *ReproducerModule,
     SmallVectorImpl<ReproducerEntry> &ReproducerCondStack,
     SmallVectorImpl<StackEntry> &DFSInStack) {
 
   CmpInst::Predicate Pred;
   Value *A, *B;
-  Instruction *And = CB.getContextInst();
-  if (!match(And->getOperand(0), m_ICmp(Pred, m_Value(A), m_Value(B))))
+  Instruction *JoinOp = CB.getContextInst();
+  CmpInst *CmpToCheck = cast<CmpInst>(CB.getInstructionToSimplify());
+  unsigned OtherOpIdx = JoinOp->getOperand(0) == CmpToCheck ? 1 : 0;
+
+  // Don't try to simplify the first condition of a select by the second, as
+  // this may make the select more poisonous than the original one.
+  // TODO: check if the first operand may be poison.
+  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);
@@ -1385,11 +1410,19 @@ static bool checkAndSecondOpImpliedByFirst(
 
   bool Changed = false;
   // Check if the second condition can be simplified now.
-  ICmpInst *Cmp = cast<ICmpInst>(And->getOperand(1));
-  if (auto ImpliedCondition = checkCondition(
-          Cmp->getPredicate(), Cmp->getOperand(0), Cmp->getOperand(1), Cmp,
-          Info, CB.NumIn, CB.NumOut, CB.getContextInst())) {
-    And->setOperand(1, ConstantInt::getBool(And->getType(), *ImpliedCondition));
+  if (auto ImpliedCondition =
+          checkCondition(CmpToCheck->getPredicate(), CmpToCheck->getOperand(0),
+                         CmpToCheck->getOperand(1), CmpToCheck, Info, CB.NumIn,
+                         CB.NumOut, CB.getContextInst())) {
+    if (IsOr && isa<SelectInst>(JoinOp)) {
+      JoinOp->setOperand(
+          OtherOpIdx == 0 ? 2 : 0,
+          ConstantInt::getBool(JoinOp->getType(), *ImpliedCondition));
+    } else
+      JoinOp->setOperand(
+          1 - OtherOpIdx,
+          ConstantInt::getBool(JoinOp->getType(), *ImpliedCondition));
+
     Changed = true;
   }
 
@@ -1442,6 +1475,17 @@ void ConstraintInfo::addFact(CmpInst::Predicate Pred, Value *A, Value *B,
     DFSInStack.emplace_back(NumIn, NumOut, R.IsSigned,
                             std::move(ValuesToRelease));
 
+    if (!R.IsSigned) {
+      for (Value *V : NewVariables) {
+        ConstraintTy VarPos(SmallVector<int64_t, 8>(Value2Index.size() + 1, 0),
+                            false, false, false);
+        VarPos.Coefficients[Value2Index[V]] = -1;
+        CSToUse.addVariableRow(VarPos.Coefficients);
+        DFSInStack.emplace_back(NumIn, NumOut, R.IsSigned,
+                                SmallVector<Value *, 2>());
+      }
+    }
+
     if (R.isEq()) {
       // Also add the inverted constraint for equality constraints.
       for (auto &Coeff : R.Coefficients)
@@ -1609,11 +1653,11 @@ static bool eliminateConstraints(Function &F, DominatorTree &DT, LoopInfo &LI,
         bool Simplified = checkAndReplaceCondition(
             Cmp, Info, CB.NumIn, CB.NumOut, CB.getContextInst(),
             ReproducerModule.get(), ReproducerCondStack, S.DT, ToRemove);
-        if (!Simplified && match(CB.getContextInst(),
-                                 m_LogicalAnd(m_Value(), m_Specific(Inst)))) {
+        if (!Simplified &&
+            match(CB.getContextInst(), m_LogicalOp(m_Value(), m_Value()))) {
           Simplified =
-              checkAndSecondOpImpliedByFirst(CB, Info, ReproducerModule.get(),
-                                             ReproducerCondStack, DFSInStack);
+              checkOrAndOpImpliedByOther(CB, Info, ReproducerModule.get(),
+                                         ReproducerCondStack, DFSInStack);
         }
         Changed |= Simplified;
       }
@@ -1687,7 +1731,8 @@ static bool eliminateConstraints(Function &F, DominatorTree &DT, LoopInfo &LI,
 #ifndef NDEBUG
   unsigned SignedEntries =
       count_if(DFSInStack, [](const StackEntry &E) { return E.IsSigned; });
-  assert(Info.getCS(false).size() == DFSInStack.size() - SignedEntries &&
+  assert(Info.getCS(false).size() - FunctionArgs.size() ==
+             DFSInStack.size() - SignedEntries &&
          "updates to CS and DFSInStack are out of sync");
   assert(Info.getCS(true).size() == SignedEntries &&
          "updates to CS and DFSInStack are out of sync");