Give RWMutex the SmartRWMutex treatment too.

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

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 94fb871dc31b2dd2ef06ed6b6e77b95dfa9d43d1..9c6941f0d318b4e263c603f9e3bb2a0db5171223 100644 (file)
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -778,8 +778,7 @@ SCEVHandle ScalarEvolution::getTruncateExpr(const SCEVHandle &Op,
   if (const SCEVZeroExtendExpr *SZ = dyn_cast<SCEVZeroExtendExpr>(Op))
     return getTruncateOrZeroExtend(SZ->getOperand(), Ty);
 
-  // If the input value is a chrec scev made out of constants, truncate
-  // all of the constants.
+  // If the input value is a chrec scev, truncate the chrec's operands.
   if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(Op)) {
     SmallVector<SCEVHandle, 4> Operands;
     for (unsigned i = 0, e = AddRec->getNumOperands(); i != e; ++i)
@@ -2453,10 +2452,25 @@ SCEVHandle ScalarEvolution::createSCEV(Value *V) {
               LCI->getValue() == CI->getValue())
             if (const SCEVZeroExtendExpr *Z =
                   dyn_cast<SCEVZeroExtendExpr>(getSCEV(U->getOperand(0)))) {
-              SCEVHandle ZO = Z->getOperand();
-              if (APIntOps::isMask(getTypeSizeInBits(ZO->getType()),
-                                   CI->getValue()))
-                return getZeroExtendExpr(getNotSCEV(ZO), U->getType());
+              const Type *UTy = U->getType();
+              SCEVHandle Z0 = Z->getOperand();
+              const Type *Z0Ty = Z0->getType();
+              unsigned Z0TySize = getTypeSizeInBits(Z0Ty);
+
+              // If C is a low-bits mask, the zero extend is zerving to
+              // mask off the high bits. Complement the operand and
+              // re-apply the zext.
+              if (APIntOps::isMask(Z0TySize, CI->getValue()))
+                return getZeroExtendExpr(getNotSCEV(Z0), UTy);
+
+              // 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() &&
+                  Trunc.isSignBit())
+                return getZeroExtendExpr(getAddExpr(Z0, getConstant(Trunc)),
+                                         UTy);
             }
     }
     break;
@@ -4010,10 +4024,9 @@ void ScalarEvolution::print(raw_ostream &OS, const Module* ) const {
       OS << "  -->  ";
       SCEVHandle SV = SE.getSCEV(&*I);
       SV->print(OS);
-      OS << "\t\t";
 
       if (const Loop *L = LI->getLoopFor((*I).getParent())) {
-        OS << "Exits: ";
+        OS << "\t\t" "Exits: ";
         SCEVHandle ExitValue = SE.getSCEVAtScope(&*I, L->getParentLoop());
         if (!ExitValue->isLoopInvariant(L)) {
           OS << "<<Unknown>>";