[ValueTracking] Add parameters to isImpliedCondition; NFC

[sanjoy]

Summary

This change makes the isImpliedCondition interface similar to the rest
of the functions in ValueTracking (in that it takes a DataLayout,
AssumptionCache etc.). This is an NFC, intended to make a later diff
less noisy.

Depends on D14369

llvm/trunk/include/llvm/Analysis/ValueTracking.h

namespace llvm {
   /// Return true if RHS is known to be implied by LHS.  A & B must be i1
   /// (boolean) values or a vector of such values. Note that the truth table for
   /// implication is the same as <=u on i1 values (but not <=s!).  The truth
   /// table for both is:
   ///    | T | F (B)
   ///  T | T | F
   ///  F | T | T
   /// (A)
-  bool isImpliedCondition(Value *LHS, Value *RHS);
+  bool isImpliedCondition(Value *LHS, Value *RHS, const DataLayout &DL,
+                          unsigned Depth = 0, AssumptionCache *AC = nullptr,
+                          const Instruction *CxtI = nullptr,
+                          const DominatorTree *DT = nullptr);
 } // end namespace llvm
 
 #endif

llvm/trunk/lib/Analysis/InstructionSimplify.cpp

case ICmpInst::ICMP_UGT:
       // X >u 0 -> X
       if (match(RHS, m_Zero()))
         return LHS;
       break;
     case ICmpInst::ICMP_UGE:
       // X >=u 1 -> X
       if (match(RHS, m_One()))
         return LHS;
-      if (isImpliedCondition(RHS, LHS))
+      if (isImpliedCondition(RHS, LHS, Q.DL))
         return getTrue(ITy);
       break;
     case ICmpInst::ICMP_SGE:
       /// For signed comparison, the values for an i1 are 0 and -1 
       /// respectively. This maps into a truth table of:
       /// LHS | RHS | LHS >=s RHS   | LHS implies RHS
       ///  0  |  0  |  1 (0 >= 0)   |  1
       ///  0  |  1  |  1 (0 >= -1)  |  1
       ///  1  |  0  |  0 (-1 >= 0)  |  0
       ///  1  |  1  |  1 (-1 >= -1) |  1
-      if (isImpliedCondition(LHS, RHS))
+      if (isImpliedCondition(LHS, RHS, Q.DL))
         return getTrue(ITy);
       break;
     case ICmpInst::ICMP_SLT:
       // X <s 0 -> X
       if (match(RHS, m_Zero()))
         return LHS;
       break;
     case ICmpInst::ICMP_SLE:
       // X <=s -1 -> X
       if (match(RHS, m_One()))
         return LHS;
       break;
     case ICmpInst::ICMP_ULE:
-      if (isImpliedCondition(LHS, RHS))
+      if (isImpliedCondition(LHS, RHS, Q.DL))
         return getTrue(ITy);
       break;
     }
   }
 
   // If we are comparing with zero then try hard since this is a common case.
   if (match(RHS, m_Zero())) {
     bool LHSKnownNonNegative, LHSKnownNegative;

llvm/trunk/lib/Analysis/ValueTracking.cpp

for (unsigned i = 1; i < NumRanges; ++i) {
     // contained in any of the original N ranges.
     CR = CR.unionWith(ConstantRange(Low->getValue(), High->getValue()));
   }
 
   return CR;
 }
 
 /// Return true if "icmp Pred LHS RHS" is always true.
-static bool isTruePredicate(CmpInst::Predicate Pred, Value *LHS, Value *RHS) {
+static bool isTruePredicate(CmpInst::Predicate Pred, Value *LHS, Value *RHS,
+                            const DataLayout &DL, unsigned Depth,
+                            AssumptionCache *AC, const Instruction *CxtI,
+                            const DominatorTree *DT) {
   if (ICmpInst::isTrueWhenEqual(Pred) && LHS == RHS)
     return true;
 
   switch (Pred) {
   default:
     return false;
 
   case CmpInst::ICMP_SLT:
case CmpInst::ICMP_ULE: {
     return false;
   }
   }
 }
 
 /// Return true if "icmp Pred BLHS BRHS" is true whenever "icmp Pred
 /// ALHS ARHS" is true.
 static bool isImpliedCondOperands(CmpInst::Predicate Pred, Value *ALHS,
-                                  Value *ARHS, Value *BLHS, Value *BRHS) {
+                                  Value *ARHS, Value *BLHS, Value *BRHS,
+                                  const DataLayout &DL, unsigned Depth,
+                                  AssumptionCache *AC, const Instruction *CxtI,
+                                  const DominatorTree *DT) {
   switch (Pred) {
   default:
     return false;
 
   case CmpInst::ICMP_SLT:
   case CmpInst::ICMP_SLE:
-    return isTruePredicate(CmpInst::ICMP_SLE, BLHS, ALHS) &&
-           isTruePredicate(CmpInst::ICMP_SLE, ARHS, BRHS);
+    return isTruePredicate(CmpInst::ICMP_SLE, BLHS, ALHS, DL, Depth, AC, CxtI,
+                           DT) &&
+           isTruePredicate(CmpInst::ICMP_SLE, ARHS, BRHS, DL, Depth, AC, CxtI,
+                           DT);
 
   case CmpInst::ICMP_ULT:
   case CmpInst::ICMP_ULE:
-    return isTruePredicate(CmpInst::ICMP_ULE, BLHS, ALHS) &&
-           isTruePredicate(CmpInst::ICMP_ULE, ARHS, BRHS);
+    return isTruePredicate(CmpInst::ICMP_ULE, BLHS, ALHS, DL, Depth, AC, CxtI,
+                           DT) &&
+           isTruePredicate(CmpInst::ICMP_ULE, ARHS, BRHS, DL, Depth, AC, CxtI,
+                           DT);
   }
 }
 
-bool llvm::isImpliedCondition(Value *LHS, Value *RHS) {
+bool llvm::isImpliedCondition(Value *LHS, Value *RHS, const DataLayout &DL,
+                              unsigned Depth, AssumptionCache *AC,
+                              const Instruction *CxtI,
+                              const DominatorTree *DT) {
   assert(LHS->getType() == RHS->getType() && "mismatched type");
   Type *OpTy = LHS->getType();
   assert(OpTy->getScalarType()->isIntegerTy(1));
 
   // LHS ==> RHS by definition
   if (LHS == RHS) return true;
 
   if (OpTy->isVectorTy())
     // TODO: extending the code below to handle vectors
     return false;
   assert(OpTy->isIntegerTy(1) && "implied by above");
 
   ICmpInst::Predicate APred, BPred;
   Value *ALHS, *ARHS;
   Value *BLHS, *BRHS;
 
   if (!match(LHS, m_ICmp(APred, m_Value(ALHS), m_Value(ARHS))) ||
       !match(RHS, m_ICmp(BPred, m_Value(BLHS), m_Value(BRHS))))
     return false;
 
   if (APred == BPred)
-    return isImpliedCondOperands(APred, ALHS, ARHS, BLHS, BRHS);
+    return isImpliedCondOperands(APred, ALHS, ARHS, BLHS, BRHS, DL, Depth, AC,
+                                 CxtI, DT);
 
   return false;
 }

llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp

bool JumpThreading::ProcessImpliedCondition(BasicBlock *BB) {
   if (!BI || !BI->isConditional())
     return false;
 
   Value *Cond = BI->getCondition();
   BasicBlock *CurrentBB = BB;
   BasicBlock *CurrentPred = BB->getSinglePredecessor();
   unsigned Iter = 0;
 
+  auto &DL = BB->getModule()->getDataLayout();
+
   while (CurrentPred && Iter++ < ImplicationSearchThreshold) {
     auto *PBI = dyn_cast<BranchInst>(CurrentPred->getTerminator());
     if (!PBI || !PBI->isConditional() || PBI->getSuccessor(0) != CurrentBB)
       return false;
 
-    if (isImpliedCondition(PBI->getCondition(), Cond)) {
+    if (isImpliedCondition(PBI->getCondition(), Cond, DL)) {
       BI->getSuccessor(1)->removePredecessor(BB);
       BranchInst::Create(BI->getSuccessor(0), BI);
       BI->eraseFromParent();
       return true;
     }
     CurrentBB = CurrentPred;
     CurrentPred = CurrentBB->getSinglePredecessor();
   }

llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp

static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI,
 
   if (auto *CE = dyn_cast<ConstantExpr>(BI->getCondition()))
     if (CE->canTrap())
       return false;
 
   // If BI is reached from the true path of PBI and PBI's condition implies
   // BI's condition, we know the direction of the BI branch.
   if (PBI->getSuccessor(0) == BI->getParent() &&
-      isImpliedCondition(PBI->getCondition(), BI->getCondition()) &&
+      isImpliedCondition(PBI->getCondition(), BI->getCondition(), DL) &&
       PBI->getSuccessor(0) != PBI->getSuccessor(1) &&
       BB->getSinglePredecessor()) {
     // Turn this into a branch on constant.
     auto *OldCond = BI->getCondition();
     BI->setCondition(ConstantInt::getTrue(BB->getContext()));
     RecursivelyDeleteTriviallyDeadInstructions(OldCond);
     return true;  // Nuke the branch on constant.
   }