Revert r230921, "Revert some changes that were made to fix PR20680.", for now.

[oota-llvm.git] / lib / Transforms / Scalar / Reassociate.cpp

diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp
index 04e724077c12c07b251abebddff9e3e46596bbad..98016b40c5643d1baaabec293a37511e3b4aab85 100644 (file)
--- a/lib/Transforms/Scalar/Reassociate.cpp
+++ b/lib/Transforms/Scalar/Reassociate.cpp
@@ -586,7 +586,7 @@ static bool LinearizeExprTree(BinaryOperator *I,
   // ways to get to it.
   SmallVector<std::pair<BinaryOperator*, APInt>, 8> Worklist; // (Op, Weight)
   Worklist.push_back(std::make_pair(I, APInt(Bitwidth, 1)));
-  bool MadeChange = false;
+  bool Changed = false;
 
   // Leaves of the expression are values that either aren't the right kind of
   // operation (eg: a constant, or a multiply in an add tree), or are, but have
@@ -623,7 +623,7 @@ static bool LinearizeExprTree(BinaryOperator *I,
       // If this is a binary operation of the right kind with only one use then
       // add its operands to the expression.
       if (BinaryOperator *BO = isReassociableOp(Op, Opcode)) {
-        assert(Visited.insert(Op) && "Not first visit!");
+        assert(Visited.insert(Op).second && "Not first visit!");
         DEBUG(dbgs() << "DIRECT ADD: " << *Op << " (" << Weight << ")\n");
         Worklist.push_back(std::make_pair(BO, Weight));
         continue;
@@ -633,7 +633,7 @@ static bool LinearizeExprTree(BinaryOperator *I,
       LeafMap::iterator It = Leaves.find(Op);
       if (It == Leaves.end()) {
         // Not in the leaf map.  Must be the first time we saw this operand.
-        assert(Visited.insert(Op) && "Not first visit!");
+        assert(Visited.insert(Op).second && "Not first visit!");
         if (!Op->hasOneUse()) {
           // This value has uses not accounted for by the expression, so it is
           // not safe to modify.  Mark it as being a leaf.
@@ -655,7 +655,7 @@ static bool LinearizeExprTree(BinaryOperator *I,
         // exactly one such use, drop this new use of the leaf.
         assert(!Op->hasOneUse() && "Only one use, but we got here twice!");
         I->setOperand(OpIdx, UndefValue::get(I->getType()));
-        MadeChange = true;
+        Changed = true;
 
         // If the leaf is a binary operation of the right kind and we now see
         // that its multiple original uses were in fact all by nodes belonging
@@ -699,7 +699,7 @@ static bool LinearizeExprTree(BinaryOperator *I,
           BO = LowerNegateToMultiply(BO);
           DEBUG(dbgs() << *BO << '\n');
           Worklist.push_back(std::make_pair(BO, Weight));
-          MadeChange = true;
+          Changed = true;
           continue;
         }
 
@@ -739,7 +739,7 @@ static bool LinearizeExprTree(BinaryOperator *I,
     Ops.push_back(std::make_pair(Identity, APInt(Bitwidth, 1)));
   }
 
-  return MadeChange;
+  return Changed;
 }
 
 // RewriteExprTree - Now that the operands for this expression tree are
@@ -791,11 +791,14 @@ void Reassociate::RewriteExprTree(BinaryOperator *I,
       Value *OldLHS = Op->getOperand(0);
       Value *OldRHS = Op->getOperand(1);
 
-      // The new operation differs trivially from the original.
-      if ((NewLHS == OldLHS && NewRHS == OldRHS) ||
-          (NewLHS == OldRHS && NewRHS == OldLHS)) {
+      if (NewLHS == OldLHS && NewRHS == OldRHS)
+        // Nothing changed, leave it alone.
+        break;
+
+      if (NewLHS == OldRHS && NewRHS == OldLHS) {
+        // The order of the operands was reversed.  Swap them.
         DEBUG(dbgs() << "RA: " << *Op << '\n');
-        canonicalizeOperands(Op);
+        Op->swapOperands();
         DEBUG(dbgs() << "TO: " << *Op << '\n');
         MadeChange = true;
         ++NumChanged;
@@ -817,8 +820,6 @@ void Reassociate::RewriteExprTree(BinaryOperator *I,
           NodesToRewrite.push_back(BO);
         Op->setOperand(1, NewRHS);
       }
-      // Put the operands in canonical form.
-      canonicalizeOperands(Op);
       DEBUG(dbgs() << "TO: " << *Op << '\n');
 
       ExpressionChanged = Op;
@@ -855,7 +856,6 @@ void Reassociate::RewriteExprTree(BinaryOperator *I,
     // into it.
     BinaryOperator *BO = isReassociableOp(Op->getOperand(0), Opcode);
     if (BO && !NotRewritable.count(BO)) {
-      canonicalizeOperands(Op);
       Op = BO;
       continue;
     }
@@ -880,7 +880,6 @@ void Reassociate::RewriteExprTree(BinaryOperator *I,
 
     DEBUG(dbgs() << "RA: " << *Op << '\n');
     Op->setOperand(0, NewOp);
-    canonicalizeOperands(Op);
     DEBUG(dbgs() << "TO: " << *Op << '\n');
     ExpressionChanged = Op;
     MadeChange = true;
@@ -918,10 +917,13 @@ void Reassociate::RewriteExprTree(BinaryOperator *I,
 /// version of the value is returned, and BI is left pointing at the instruction
 /// that should be processed next by the reassociation pass.
 static Value *NegateValue(Value *V, Instruction *BI) {
-  if (ConstantFP *C = dyn_cast<ConstantFP>(V))
-    return ConstantExpr::getFNeg(C);
-  if (Constant *C = dyn_cast<Constant>(V))
+  if (Constant *C = dyn_cast<Constant>(V)) {
+    if (C->getType()->isFPOrFPVectorTy()) {
+      return ConstantExpr::getFNeg(C);
+    }
     return ConstantExpr::getNeg(C);
+  }
+
 
   // We are trying to expose opportunity for reassociation.  One of the things
   // that we want to do to achieve this is to push a negation as deep into an
@@ -1513,7 +1515,7 @@ Value *Reassociate::OptimizeAdd(Instruction *I,
         ++NumFound;
       } while (i != Ops.size() && Ops[i].Op == TheOp);
 
-      DEBUG(errs() << "\nFACTORING [" << NumFound << "]: " << *TheOp << '\n');
+      DEBUG(dbgs() << "\nFACTORING [" << NumFound << "]: " << *TheOp << '\n');
       ++NumFactor;
 
       // Insert a new multiply.
@@ -1609,7 +1611,7 @@ Value *Reassociate::OptimizeAdd(Instruction *I,
     SmallPtrSet<Value*, 8> Duplicates;
     for (unsigned i = 0, e = Factors.size(); i != e; ++i) {
       Value *Factor = Factors[i];
-      if (!Duplicates.insert(Factor))
+      if (!Duplicates.insert(Factor).second)
         continue;
 
       unsigned Occ = ++FactorOccurrences[Factor];
@@ -1651,7 +1653,7 @@ Value *Reassociate::OptimizeAdd(Instruction *I,
 
   // If any factor occurred more than one time, we can pull it out.
   if (MaxOcc > 1) {
-    DEBUG(errs() << "\nFACTORING [" << MaxOcc << "]: " << *MaxOccVal << '\n');
+    DEBUG(dbgs() << "\nFACTORING [" << MaxOcc << "]: " << *MaxOccVal << '\n');
     ++NumFactor;
 
     // Create a new instruction that uses the MaxOccVal twice.  If we don't do
@@ -1960,7 +1962,7 @@ void Reassociate::EraseInst(Instruction *I) {
       // and add that since that's where optimization actually happens.
       unsigned Opcode = Op->getOpcode();
       while (Op->hasOneUse() && Op->user_back()->getOpcode() == Opcode &&
-             Visited.insert(Op))
+             Visited.insert(Op).second)
         Op = Op->user_back();
       RedoInsts.insert(Op);
     }
@@ -1989,7 +1991,7 @@ Instruction *Reassociate::canonicalizeNegConstExpr(Instruction *I) {
   Constant *C = C0 ? C0 : C1;
   unsigned ConstIdx = C0 ? 0 : 1;
   if (auto *CI = dyn_cast<ConstantInt>(C)) {
-    if (!CI->isNegative())
+    if (!CI->isNegative() || CI->isMinValue(true))
       return nullptr;
   } else if (auto *CF = dyn_cast<ConstantFP>(C)) {
     if (!CF->isNegative())