PR5207: Change APInt methods trunc(), sext(), zext(), sextOrTrunc() and

zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121120 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 18 insertions, 22 deletions

diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 74bee94..3ab18fd 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -206,14 +206,14 @@ static Value *GetLinearExpression(Value *V, APInt &Scale, APInt &Offset,
     Value *CastOp = cast<CastInst>(V)->getOperand(0);
     unsigned OldWidth = Scale.getBitWidth();
     unsigned SmallWidth = CastOp->getType()->getPrimitiveSizeInBits();
-    Scale.trunc(SmallWidth);
-    Offset.trunc(SmallWidth);
+    Scale = Scale.trunc(SmallWidth);
+    Offset = Offset.trunc(SmallWidth);
     Extension = isa<SExtInst>(V) ? EK_SignExt : EK_ZeroExt;
 
     Value *Result = GetLinearExpression(CastOp, Scale, Offset, Extension,
                                         TD, Depth+1);
-    Scale.zext(OldWidth);
-    Offset.zext(OldWidth);
+    Scale = Scale.zext(OldWidth);
+    Offset = Offset.zext(OldWidth);
     
     return Result;
   }
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 70ee9dd..68a55b6 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -610,10 +610,8 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps,
   APInt BasePtr(BitWidth, 0);
   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
     if (CE->getOpcode() == Instruction::IntToPtr)
-      if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0))) {
-        BasePtr = Base->getValue();
-        BasePtr.zextOrTrunc(BitWidth);
-      }
+      if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0)))
+        BasePtr = Base->getValue().zextOrTrunc(BitWidth);
   if (Ptr->isNullValue() || BasePtr != 0) {
     Constant *C = ConstantInt::get(Ptr->getContext(), Offset+BasePtr);
     return ConstantExpr::getIntToPtr(C, ResultTy);
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 7e50d3d..b0c1c75 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -3367,8 +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);
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index 7ab4d2b..a612f13 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -255,14 +255,13 @@ void llvm::ComputeMaskedBits(Value *V, const APInt &Mask,
     else
       SrcBitWidth = SrcTy->getScalarSizeInBits();
     
-    APInt MaskIn(Mask);
-    MaskIn.zextOrTrunc(SrcBitWidth);
-    KnownZero.zextOrTrunc(SrcBitWidth);
-    KnownOne.zextOrTrunc(SrcBitWidth);
+    APInt MaskIn = Mask.zextOrTrunc(SrcBitWidth);
+    KnownZero = KnownZero.zextOrTrunc(SrcBitWidth);
+    KnownOne = KnownOne.zextOrTrunc(SrcBitWidth);
     ComputeMaskedBits(I->getOperand(0), MaskIn, KnownZero, KnownOne, TD,
                       Depth+1);
-    KnownZero.zextOrTrunc(BitWidth);
-    KnownOne.zextOrTrunc(BitWidth);
+    KnownZero = KnownZero.zextOrTrunc(BitWidth);
+    KnownOne = KnownOne.zextOrTrunc(BitWidth);
     // Any top bits are known to be zero.
     if (BitWidth > SrcBitWidth)
       KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - SrcBitWidth);
@@ -284,15 +283,14 @@ void llvm::ComputeMaskedBits(Value *V, const APInt &Mask,
     // Compute the bits in the result that are not present in the input.
     unsigned SrcBitWidth = I->getOperand(0)->getType()->getScalarSizeInBits();
       
-    APInt MaskIn(Mask); 
-    MaskIn.trunc(SrcBitWidth);
-    KnownZero.trunc(SrcBitWidth);
-    KnownOne.trunc(SrcBitWidth);
+    APInt MaskIn = Mask.trunc(SrcBitWidth);
+    KnownZero = KnownZero.trunc(SrcBitWidth);
+    KnownOne = KnownOne.trunc(SrcBitWidth);
     ComputeMaskedBits(I->getOperand(0), MaskIn, KnownZero, KnownOne, TD,
                       Depth+1);
     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
-    KnownZero.zext(BitWidth);
-    KnownOne.zext(BitWidth);
+    KnownZero = KnownZero.zext(BitWidth);
+    KnownOne = KnownOne.zext(BitWidth);
 
     // If the sign bit of the input is known set or clear, then we know the
     // top bits of the result.