[llvm] r298180 - [ValueTracking] Add APInt::setSignBit and use it to replace ORing with getSignBit which will malloc if the bit width is larger than 64.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Fri Mar 17 23:01:29 2017
New Revision: 298180

URL: http://llvm.org/viewvc/llvm-project?rev=298180&view=rev
Log:
[ValueTracking] Add APInt::setSignBit and use it to replace ORing with getSignBit which will malloc if the bit width is larger than 64.

Modified:
    llvm/trunk/include/llvm/ADT/APInt.h
    llvm/trunk/lib/Analysis/ValueTracking.cpp

Modified: llvm/trunk/include/llvm/ADT/APInt.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/APInt.h?rev=298180&r1=298179&r2=298180&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/APInt.h (original)
+++ llvm/trunk/include/llvm/ADT/APInt.h Fri Mar 17 23:01:29 2017
@@ -1175,6 +1175,11 @@ public:
   /// Set the given bit to 1 whose position is given as "bitPosition".
   void setBit(unsigned bitPosition);
 
+  /// Set the sign bit to 1.
+  void setSignBit() {
+    setBit(BitWidth - 1);
+  }
+
   /// Set the bits from loBit (inclusive) to hiBit (exclusive) to 1.
   void setBits(unsigned loBit, unsigned hiBit) {
     assert(hiBit <= BitWidth && "hiBit out of range");

Modified: llvm/trunk/lib/Analysis/ValueTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ValueTracking.cpp?rev=298180&r1=298179&r2=298180&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ValueTracking.cpp (original)
+++ llvm/trunk/lib/Analysis/ValueTracking.cpp Fri Mar 17 23:01:29 2017
@@ -321,11 +321,11 @@ static void computeKnownBitsAddSub(bool
       // Adding two non-negative numbers, or subtracting a negative number from
       // a non-negative one, can't wrap into negative.
       if (LHSKnownZero.isNegative() && KnownZero2.isNegative())
-        KnownZero |= APInt::getSignBit(BitWidth);
+        KnownZero.setSignBit();
       // Adding two negative numbers, or subtracting a non-negative number from
       // a negative one, can't wrap into non-negative.
       else if (LHSKnownOne.isNegative() && KnownOne2.isNegative())
-        KnownOne |= APInt::getSignBit(BitWidth);
+        KnownOne.setSignBit();
     }
   }
 }
@@ -732,7 +732,7 @@ static void computeKnownBitsFromAssume(c
 
       if (RHSKnownZero.isNegative()) {
         // We know that the sign bit is zero.
-        KnownZero |= APInt::getSignBit(BitWidth);
+        KnownZero.setSignBit();
       }
     // assume(v >_s c) where c is at least -1.
     } else if (match(Arg, m_ICmp(Pred, m_V, m_Value(A))) &&
@@ -743,7 +743,7 @@ static void computeKnownBitsFromAssume(c
 
       if (RHSKnownOne.isAllOnesValue() || RHSKnownZero.isNegative()) {
         // We know that the sign bit is zero.
-        KnownZero |= APInt::getSignBit(BitWidth);
+        KnownZero.setSignBit();
       }
     // assume(v <=_s c) where c is negative
     } else if (match(Arg, m_ICmp(Pred, m_V, m_Value(A))) &&
@@ -754,7 +754,7 @@ static void computeKnownBitsFromAssume(c
 
       if (RHSKnownOne.isNegative()) {
         // We know that the sign bit is one.
-        KnownOne |= APInt::getSignBit(BitWidth);
+        KnownOne.setSignBit();
       }
     // assume(v <_s c) where c is non-positive
     } else if (match(Arg, m_ICmp(Pred, m_V, m_Value(A))) &&
@@ -765,7 +765,7 @@ static void computeKnownBitsFromAssume(c
 
       if (RHSKnownZero.isAllOnesValue() || RHSKnownOne.isNegative()) {
         // We know that the sign bit is one.
-        KnownOne |= APInt::getSignBit(BitWidth);
+        KnownOne.setSignBit();
       }
     // assume(v <=_u c)
     } else if (match(Arg, m_ICmp(Pred, m_V, m_Value(A))) &&