1 files changed, 21 insertions, 26 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index e946acf84f5..030461004f5 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -17,6 +17,7 @@
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/GetElementPtrTypeIterator.h"
 #include "llvm/IR/PatternMatch.h"
+#include "llvm/Support/KnownBits.h"
 
 using namespace llvm;
 using namespace PatternMatch;
@@ -899,24 +900,22 @@ bool InstCombiner::WillNotOverflowSignedAdd(Value *LHS, Value *RHS,
     return true;
 
   unsigned BitWidth = LHS->getType()->getScalarSizeInBits();
-  APInt LHSKnownZero(BitWidth, 0);
-  APInt LHSKnownOne(BitWidth, 0);
-  computeKnownBits(LHS, LHSKnownZero, LHSKnownOne, 0, &CxtI);
+  KnownBits LHSKnown(BitWidth);
+  computeKnownBits(LHS, LHSKnown, 0, &CxtI);
 
-  APInt RHSKnownZero(BitWidth, 0);
-  APInt RHSKnownOne(BitWidth, 0);
-  computeKnownBits(RHS, RHSKnownZero, RHSKnownOne, 0, &CxtI);
+  KnownBits RHSKnown(BitWidth);
+  computeKnownBits(RHS, RHSKnown, 0, &CxtI);
 
   // Addition of two 2's complement numbers having opposite signs will never
   // overflow.
-  if ((LHSKnownOne[BitWidth - 1] && RHSKnownZero[BitWidth - 1]) ||
-      (LHSKnownZero[BitWidth - 1] && RHSKnownOne[BitWidth - 1]))
+  if ((LHSKnown.One[BitWidth - 1] && RHSKnown.Zero[BitWidth - 1]) ||
+      (LHSKnown.Zero[BitWidth - 1] && RHSKnown.One[BitWidth - 1]))
     return true;
 
   // Check if carry bit of addition will not cause overflow.
-  if (checkRippleForAdd(LHSKnownZero, RHSKnownZero))
+  if (checkRippleForAdd(LHSKnown.Zero, RHSKnown.Zero))
     return true;
-  if (checkRippleForAdd(RHSKnownZero, LHSKnownZero))
+  if (checkRippleForAdd(RHSKnown.Zero, LHSKnown.Zero))
     return true;
 
   return false;
@@ -936,18 +935,16 @@ bool InstCombiner::WillNotOverflowSignedSub(Value *LHS, Value *RHS,
     return true;
 
   unsigned BitWidth = LHS->getType()->getScalarSizeInBits();
-  APInt LHSKnownZero(BitWidth, 0);
-  APInt LHSKnownOne(BitWidth, 0);
-  computeKnownBits(LHS, LHSKnownZero, LHSKnownOne, 0, &CxtI);
+  KnownBits LHSKnown(BitWidth);
+  computeKnownBits(LHS, LHSKnown, 0, &CxtI);
 
-  APInt RHSKnownZero(BitWidth, 0);
-  APInt RHSKnownOne(BitWidth, 0);
-  computeKnownBits(RHS, RHSKnownZero, RHSKnownOne, 0, &CxtI);
+  KnownBits RHSKnown(BitWidth);
+  computeKnownBits(RHS, RHSKnown, 0, &CxtI);
 
   // Subtraction of two 2's complement numbers having identical signs will
   // never overflow.
-  if ((LHSKnownOne[BitWidth - 1] && RHSKnownOne[BitWidth - 1]) ||
-      (LHSKnownZero[BitWidth - 1] && RHSKnownZero[BitWidth - 1]))
+  if ((LHSKnown.One[BitWidth - 1] && RHSKnown.One[BitWidth - 1]) ||
+      (LHSKnown.Zero[BitWidth - 1] && RHSKnown.Zero[BitWidth - 1]))
     return true;
 
   // TODO: implement logic similar to checkRippleForAdd
@@ -1118,10 +1115,9 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
       // a sub and fuse this add with it.
       if (LHS->hasOneUse() && (XorRHS->getValue()+1).isPowerOf2()) {
         IntegerType *IT = cast<IntegerType>(I.getType());
-        APInt LHSKnownOne(IT->getBitWidth(), 0);
-        APInt LHSKnownZero(IT->getBitWidth(), 0);
-        computeKnownBits(XorLHS, LHSKnownZero, LHSKnownOne, 0, &I);
-        if ((XorRHS->getValue() | LHSKnownZero).isAllOnesValue())
+        KnownBits LHSKnown(IT->getBitWidth());
+        computeKnownBits(XorLHS, LHSKnown, 0, &I);
+        if ((XorRHS->getValue() | LHSKnown.Zero).isAllOnesValue())
           return BinaryOperator::CreateSub(ConstantExpr::getAdd(XorRHS, CI),
                                            XorLHS);
       }
@@ -1641,10 +1637,9 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) {
     // Turn this into a xor if LHS is 2^n-1 and the remaining bits are known
     // zero.
     if (Op0C->isMask()) {
-      APInt RHSKnownZero(BitWidth, 0);
-      APInt RHSKnownOne(BitWidth, 0);
-      computeKnownBits(Op1, RHSKnownZero, RHSKnownOne, 0, &I);
-      if ((*Op0C | RHSKnownZero).isAllOnesValue())
+      KnownBits RHSKnown(BitWidth);
+      computeKnownBits(Op1, RHSKnown, 0, &I);
+      if ((*Op0C | RHSKnown.Zero).isAllOnesValue())
         return BinaryOperator::CreateXor(Op1, Op0);
     }
   }