[llvm] ConstraintSystem: replace data structure with Matrix (PR #98895)

[Ramkumar Ramachandra via llvm-commits]

================
@@ -1725,6 +1786,74 @@ static bool eliminateConstraints(Function &F, DominatorTree &DT, LoopInfo &LI,
     return A.NumIn < B.NumIn;
   });
 
+  for (const FactOrCheck &CB : S.WorkList) {
+    ICmpInst::Predicate Pred;
+    Value *A, *B;
+    if (CB.isCheck()) {
+      if (auto *Cmp = dyn_cast<ICmpInst>(CB.getInstructionToSimplify())) {
+        if (!checkCondition(Cmp->getPredicate(), Cmp->getOperand(0),
+                            Cmp->getOperand(1), Cmp, Info) &&
+            match(CB.getContextInst(), m_LogicalOp(m_Value(), m_Value()))) {
+          match(Cmp, m_ICmp(Pred, m_Value(A), m_Value(B)));
+          EstimatedColumns += getNumNewVars(Pred, A, B, Info, SeenVars);
+        }
+      }
+      continue;
+    }
+    if (!CB.isConditionFact()) {
+      Value *X;
+      if (match(CB.Inst, m_Intrinsic<Intrinsic::abs>(m_Value(X)))) {
+        if (cast<ConstantInt>(CB.Inst->getOperand(1))->isOne())
+          EstimatedColumns += getNumNewVars(
+              CmpInst::ICMP_SGE, CB.Inst,
+              ConstantInt::get(CB.Inst->getType(), 0), Info, SeenVars);
+        EstimatedColumns +=
+            getNumNewVars(CmpInst::ICMP_SGE, CB.Inst, X, Info, SeenVars);
+        continue;
+      }
+
+      if (auto *MinMax = dyn_cast<MinMaxIntrinsic>(CB.Inst)) {
+        Pred = ICmpInst::getNonStrictPredicate(MinMax->getPredicate());
+        EstimatedColumns +=
+            getNumNewVars(Pred, MinMax, MinMax->getLHS(), Info, SeenVars);
+        EstimatedColumns +=
+            getNumNewVars(Pred, MinMax, MinMax->getRHS(), Info, SeenVars);
+        continue;
+      }
+    }
+
+    if (CB.isConditionFact()) {
+      Pred = CB.Cond.Pred;
+      A = CB.Cond.Op0;
+      B = CB.Cond.Op1;
+    } else {
+      match(CB.Inst, m_Intrinsic<Intrinsic::assume>(
+                         m_ICmp(Pred, m_Value(A), m_Value(B))));
+    }
+    EstimatedColumns += getNumNewVars(Pred, A, B, Info, SeenVars);
+  }
+  return {S, EstimatedColumns};
+}
+
+static bool eliminateConstraints(Function &F, DominatorTree &DT, LoopInfo &LI,
+                                 ScalarEvolution &SE,
+                                 OptimizationRemarkEmitter &ORE) {
+  bool Changed = false;
+  DT.updateDFSNumbers();
+  SmallVector<Value *> FunctionArgs;
+  for (Value &Arg : F.args())
+    FunctionArgs.push_back(&Arg);
+  auto [S, EstimatedColumns] = dryRun(F, DT, LI, SE);
----------------
artagnon wrote:

I've used a `const_cast` on CB when passed to `checkOrAndOpImpliedByOther`. Let me know if this is what you meant.

https://github.com/llvm/llvm-project/pull/98895