Revert r122114 (CallbackVH observing use-list changes) because it caused severe slowd...

[oota-llvm.git] / lib / Analysis / ScalarEvolution.cpp

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 04ec67f5b397b9f9bcdd6edcf820158d307746aa..b0c1c75cb6abfc08791557e9d01f80f79b2858d4 100644 (file)
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -166,7 +166,7 @@ void SCEV::print(raw_ostream &OS) const {
   case scUMaxExpr:
   case scSMaxExpr: {
     const SCEVNAryExpr *NAry = cast<SCEVNAryExpr>(this);
-    const char *OpStr;
+    const char *OpStr = 0;
     switch (NAry->getSCEVType()) {
     case scAddExpr: OpStr = " + "; break;
     case scMulExpr: OpStr = " * "; break;
@@ -2768,25 +2768,10 @@ const SCEV *ScalarEvolution::createNodeForPHI(PHINode *PN) {
   // PHI's incoming blocks are in a different loop, in which case doing so
   // risks breaking LCSSA form. Instcombine would normally zap these, but
   // it doesn't have DominatorTree information, so it may miss cases.
-  if (Value *V = SimplifyInstruction(PN, TD, DT)) {
-    Instruction *I = dyn_cast<Instruction>(V);
-    // Only instructions are problematic for preserving LCSSA form.
-    if (!I)
+  if (Value *V = SimplifyInstruction(PN, TD, DT))
+    if (LI->replacementPreservesLCSSAForm(PN, V))
       return getSCEV(V);
 
-    // If the instruction is not defined in a loop, then it can be used freely.
-    Loop *ILoop = LI->getLoopFor(I->getParent());
-    if (!ILoop)
-      return getSCEV(I);
-
-    // If the instruction is defined in the same loop as the phi node, or in a
-    // loop that contains the phi node loop as an inner loop, then using it as
-    // a replacement for the phi node will not break LCSSA form.
-    Loop *PNLoop = LI->getLoopFor(PN->getParent());
-    if (ILoop->contains(PNLoop))
-      return getSCEV(I);
-  }
-
   // If it's not a loop phi, we can't handle it yet.
   return getUnknown(PN);
 }
@@ -3382,8 +3367,8 @@ const SCEV *ScalarEvolution::createSCEV(Value *V) {
               // If C is a single bit, it may be in the sign-bit position
               // before the zero-extend. In this case, represent the xor
               // using an add, which is equivalent, and re-apply the zext.
-              APInt Trunc = APInt(CI->getValue()).trunc(Z0TySize);
-              if (APInt(Trunc).zext(getTypeSizeInBits(UTy)) == CI->getValue() &&
+              APInt Trunc = CI->getValue().trunc(Z0TySize);
+              if (Trunc.zext(getTypeSizeInBits(UTy)) == CI->getValue() &&
                   Trunc.isSignBit())
                 return getZeroExtendExpr(getAddExpr(Z0, getConstant(Trunc)),
                                          UTy);
@@ -4617,7 +4602,7 @@ static const SCEV *SolveLinEquationWithOverflow(const APInt &A, const APInt &B,
   // bit width during computations.
   APInt AD = A.lshr(Mult2).zext(BW + 1);  // AD = A / D
   APInt Mod(BW + 1, 0);
-  Mod.set(BW - Mult2);  // Mod = N / D
+  Mod.setBit(BW - Mult2);  // Mod = N / D
   APInt I = AD.multiplicativeInverse(Mod);
 
   // 4. Compute the minimum unsigned root of the equation:
@@ -5090,13 +5075,13 @@ bool ScalarEvolution::SimplifyICmpOperands(ICmpInst::Predicate &Pred,
 
 trivially_true:
   // Return 0 == 0.
-  LHS = RHS = getConstant(Type::getInt1Ty(getContext()), 0);
+  LHS = RHS = getConstant(ConstantInt::getFalse(getContext()));
   Pred = ICmpInst::ICMP_EQ;
   return true;
 
 trivially_false:
   // Return 0 != 0.
-  LHS = RHS = getConstant(Type::getInt1Ty(getContext()), 0);
+  LHS = RHS = getConstant(ConstantInt::getFalse(getContext()));
   Pred = ICmpInst::ICMP_NE;
   return true;
 }