[llvm] r186095 - Don't use a potentially expensive shift if all we want is one set bit.

[Benjamin Kramer]

Author: d0k
Date: Thu Jul 11 11:05:50 2013
New Revision: 186095

URL: http://llvm.org/viewvc/llvm-project?rev=186095&view=rev
Log:
Don't use a potentially expensive shift if all we want is one set bit.

No functionality change.

Modified:
    llvm/trunk/lib/Analysis/ScalarEvolution.cpp
    llvm/trunk/lib/Support/ConstantRange.cpp
    llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp
    llvm/trunk/lib/Transforms/Utils/SimplifyIndVar.cpp

Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=186095&r1=186094&r2=186095&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Thu Jul 11 11:05:50 2013
@@ -758,7 +758,7 @@ static const SCEV *BinomialCoefficient(c
   unsigned CalculationBits = W + T;
 
   // Calculate 2^T, at width T+W.
-  APInt DivFactor = APInt(CalculationBits, 1).shl(T);
+  APInt DivFactor = APInt::getOneBitSet(CalculationBits, T);
 
   // Calculate the multiplicative inverse of K! / 2^T;
   // this multiplication factor will perform the exact division by
@@ -3789,7 +3789,7 @@ const SCEV *ScalarEvolution::createSCEV(
         break;
 
       Constant *X = ConstantInt::get(getContext(),
-        APInt(BitWidth, 1).shl(SA->getZExtValue()));
+        APInt::getOneBitSet(BitWidth, SA->getZExtValue()));
       return getMulExpr(getSCEV(U->getOperand(0)), getSCEV(X));
     }
     break;
@@ -3807,7 +3807,7 @@ const SCEV *ScalarEvolution::createSCEV(
         break;
 
       Constant *X = ConstantInt::get(getContext(),
-        APInt(BitWidth, 1).shl(SA->getZExtValue()));
+        APInt::getOneBitSet(BitWidth, SA->getZExtValue()));
       return getUDivExpr(getSCEV(U->getOperand(0)), getSCEV(X));
     }
     break;

Modified: llvm/trunk/lib/Support/ConstantRange.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/ConstantRange.cpp?rev=186095&r1=186094&r2=186095&view=diff
==============================================================================
--- llvm/trunk/lib/Support/ConstantRange.cpp (original)
+++ llvm/trunk/lib/Support/ConstantRange.cpp Thu Jul 11 11:05:50 2013
@@ -433,7 +433,7 @@ ConstantRange ConstantRange::zeroExtend(
     APInt LowerExt(DstTySize, 0);
     if (!Upper) // special case: [X, 0) -- not really wrapping around
       LowerExt = Lower.zext(DstTySize);
-    return ConstantRange(LowerExt, APInt(DstTySize, 1).shl(SrcTySize));
+    return ConstantRange(LowerExt, APInt::getOneBitSet(DstTySize, SrcTySize));
   }
 
   return ConstantRange(Lower.zext(DstTySize), Upper.zext(DstTySize));

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp?rev=186095&r1=186094&r2=186095&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp Thu Jul 11 11:05:50 2013
@@ -876,7 +876,7 @@ static inline Value *dyn_castFoldableMul
       uint32_t BitWidth = cast<IntegerType>(V->getType())->getBitWidth();
       uint32_t CSTVal = CST->getLimitedValue(BitWidth);
       CST = ConstantInt::get(V->getType()->getContext(),
-                             APInt(BitWidth, 1).shl(CSTVal));
+                             APInt::getOneBitSet(BitWidth, CSTVal));
       return I->getOperand(0);
     }
   return 0;

Modified: llvm/trunk/lib/Transforms/Utils/SimplifyIndVar.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyIndVar.cpp?rev=186095&r1=186094&r2=186095&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyIndVar.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyIndVar.cpp Thu Jul 11 11:05:50 2013
@@ -119,7 +119,7 @@ Value *SimplifyIndvar::foldIVUser(Instru
         return 0;
 
       D = ConstantInt::get(UseInst->getContext(),
-                           APInt(BitWidth, 1).shl(D->getZExtValue()));
+                           APInt::getOneBitSet(BitWidth, D->getZExtValue()));
     }
     FoldedExpr = SE->getUDivExpr(SE->getSCEV(IVSrc), SE->getSCEV(D));
   }