When substituting sunkaddrs into indirect arguments an asm, we were

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

diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp
index 4a99f4a844ec265a5717b69e529a489a2d0d74a7..b8afcc12d927d165e3e6aa82763932cdf73b96cc 100644 (file)
--- a/lib/Transforms/Scalar/Reassociate.cpp
+++ b/lib/Transforms/Scalar/Reassociate.cpp
@@ -77,7 +77,7 @@ namespace {
     bool MadeChange;
   public:
     static char ID; // Pass identification, replacement for typeid
-    Reassociate() : FunctionPass(&ID) {}
+    Reassociate() : FunctionPass(ID) {}
 
     bool runOnFunction(Function &F);
 
@@ -103,7 +103,8 @@ namespace {
 }
 
 char Reassociate::ID = 0;
-static RegisterPass<Reassociate> X("reassociate", "Reassociate expressions");
+INITIALIZE_PASS(Reassociate, "reassociate",
+                "Reassociate expressions", false, false);
 
 // Public interface to the Reassociate pass
 FunctionPass *llvm::createReassociatePass() { return new Reassociate(); }
@@ -182,7 +183,7 @@ unsigned Reassociate::getRank(Value *V) {
 
   // If this is a not or neg instruction, do not count it for rank.  This
   // assures us that X and ~X will have the same rank.
-  if (!I->getType()->isInteger() ||
+  if (!I->getType()->isIntegerTy() ||
       (!BinaryOperator::isNot(I) && !BinaryOperator::isNeg(I)))
     ++Rank;
 
@@ -249,7 +250,7 @@ void Reassociate::LinearizeExpr(BinaryOperator *I) {
 
 /// LinearizeExprTree - Given an associative binary expression tree, traverse
 /// all of the uses putting it into canonical form.  This forces a left-linear
-/// form of the the expression (((a+b)+c)+d), and collects information about the
+/// form of the expression (((a+b)+c)+d), and collects information about the
 /// rank of the non-tree operands.
 ///
 /// NOTE: These intentionally destroys the expression tree operands (turning
@@ -299,7 +300,7 @@ void Reassociate::LinearizeExprTree(BinaryOperator *I,
     Success = false;
     MadeChange = true;
   } else if (RHSBO) {
-    // Turn (A+B)+(C+D) -> (((A+B)+C)+D).  This guarantees the the RHS is not
+    // Turn (A+B)+(C+D) -> (((A+B)+C)+D).  This guarantees the RHS is not
     // part of the expression tree.
     LinearizeExpr(I);
     LHS = LHSBO = cast<BinaryOperator>(I->getOperand(0));
@@ -407,13 +408,14 @@ static Value *NegateValue(Value *V, Instruction *BI) {
   // Okay, we need to materialize a negated version of V with an instruction.
   // Scan the use lists of V to see if we have one already.
   for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E;++UI){
-    if (!BinaryOperator::isNeg(*UI)) continue;
+    User *U = *UI;
+    if (!BinaryOperator::isNeg(U)) continue;
 
     // We found one!  Now we have to make sure that the definition dominates
     // this use.  We do this by moving it to the entry block (if it is a
     // non-instruction value) or right after the definition.  These negates will
     // be zapped by reassociate later, so we don't need much finesse here.
-    BinaryOperator *TheNeg = cast<BinaryOperator>(*UI);
+    BinaryOperator *TheNeg = cast<BinaryOperator>(U);
 
     // Verify that the negate is in this function, V might be a constant expr.
     if (TheNeg->getParent()->getParent() != BI->getParent()->getParent())
@@ -597,19 +599,35 @@ Value *Reassociate::RemoveFactorFromExpression(Value *V, Value *Factor) {
 
 /// FindSingleUseMultiplyFactors - If V is a single-use multiply, recursively
 /// add its operands as factors, otherwise add V to the list of factors.
+///
+/// Ops is the top-level list of add operands we're trying to factor.
 static void FindSingleUseMultiplyFactors(Value *V,
-                                         SmallVectorImpl<Value*> &Factors) {
+                                         SmallVectorImpl<Value*> &Factors,
+                                       const SmallVectorImpl<ValueEntry> &Ops,
+                                         bool IsRoot) {
   BinaryOperator *BO;
-  if ((!V->hasOneUse() && !V->use_empty()) ||
+  if (!(V->hasOneUse() || V->use_empty()) || // More than one use.
       !(BO = dyn_cast<BinaryOperator>(V)) ||
       BO->getOpcode() != Instruction::Mul) {
     Factors.push_back(V);
     return;
   }
   
+  // If this value has a single use because it is another input to the add
+  // tree we're reassociating and we dropped its use, it actually has two
+  // uses and we can't factor it.
+  if (!IsRoot) {
+    for (unsigned i = 0, e = Ops.size(); i != e; ++i)
+      if (Ops[i].Op == V) {
+        Factors.push_back(V);
+        return;
+      }
+  }
+  
+  
   // Otherwise, add the LHS and RHS to the list of factors.
-  FindSingleUseMultiplyFactors(BO->getOperand(1), Factors);
-  FindSingleUseMultiplyFactors(BO->getOperand(0), Factors);
+  FindSingleUseMultiplyFactors(BO->getOperand(1), Factors, Ops, false);
+  FindSingleUseMultiplyFactors(BO->getOperand(0), Factors, Ops, false);
 }
 
 /// OptimizeAndOrXor - Optimize a series of operands to an 'and', 'or', or 'xor'
@@ -753,7 +771,7 @@ Value *Reassociate::OptimizeAdd(Instruction *I,
     
     // Compute all of the factors of this added value.
     SmallVector<Value*, 8> Factors;
-    FindSingleUseMultiplyFactors(BOp, Factors);
+    FindSingleUseMultiplyFactors(BOp, Factors, Ops, true);
     assert(Factors.size() > 1 && "Bad linearize!");
     
     // Add one to FactorOccurrences for each unique factor in this op.
@@ -929,10 +947,19 @@ void Reassociate::ReassociateBB(BasicBlock *BB) {
       }
 
     // Reject cases where it is pointless to do this.
-    if (!isa<BinaryOperator>(BI) || BI->getType()->isFloatingPoint() || 
-        isa<VectorType>(BI->getType()))
+    if (!isa<BinaryOperator>(BI) || BI->getType()->isFloatingPointTy() || 
+        BI->getType()->isVectorTy())
       continue;  // Floating point ops are not associative.
 
+    // Do not reassociate boolean (i1) expressions.  We want to preserve the
+    // original order of evaluation for short-circuited comparisons that
+    // SimplifyCFG has folded to AND/OR expressions.  If the expression
+    // is not further optimized, it is likely to be transformed back to a
+    // short-circuited form for code gen, and the source order may have been
+    // optimized for the most likely conditions.
+    if (BI->getType()->isIntegerTy(1))
+      continue;
+
     // If this is a subtract instruction which is not already in negate form,
     // see if we can convert it to X+-Y.
     if (BI->getOpcode() == Instruction::Sub) {