[ValueTracking] Convert most of the calls to computeKnownBits to use the version that returns the KnownBits object.

This continues the changes started when computeSignBit was replaced with this new version of computeKnowBits.

Differential Revision: https://reviews.llvm.org/D33431

llvm-svn: 303773

1 files changed, 4 insertions, 10 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index 733eeb1767a..7204bf51768 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -861,12 +861,9 @@ bool InstCombiner::willNotOverflowSignedSub(const Value *LHS,
       ComputeNumSignBits(RHS, 0, &CxtI) > 1)
     return true;
 
-  unsigned BitWidth = LHS->getType()->getScalarSizeInBits();
-  KnownBits LHSKnown(BitWidth);
-  computeKnownBits(LHS, LHSKnown, 0, &CxtI);
+  KnownBits LHSKnown = computeKnownBits(LHS, 0, &CxtI);
 
-  KnownBits RHSKnown(BitWidth);
-  computeKnownBits(RHS, RHSKnown, 0, &CxtI);
+  KnownBits RHSKnown = computeKnownBits(RHS, 0, &CxtI);
 
   // Subtraction of two 2's complement numbers having identical signs will
   // never overflow.
@@ -1059,9 +1056,7 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
       // If this is a xor that was canonicalized from a sub, turn it back into
       // a sub and fuse this add with it.
       if (LHS->hasOneUse() && (XorRHS->getValue()+1).isPowerOf2()) {
-        IntegerType *IT = cast<IntegerType>(I.getType());
-        KnownBits LHSKnown(IT->getBitWidth());
-        computeKnownBits(XorLHS, LHSKnown, 0, &I);
+        KnownBits LHSKnown = computeKnownBits(XorLHS, 0, &I);
         if ((XorRHS->getValue() | LHSKnown.Zero).isAllOnesValue())
           return BinaryOperator::CreateSub(ConstantExpr::getAdd(XorRHS, CI),
                                            XorLHS);
@@ -1577,8 +1572,7 @@ 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()) {
-      KnownBits RHSKnown(BitWidth);
-      computeKnownBits(Op1, RHSKnown, 0, &I);
+      KnownBits RHSKnown = computeKnownBits(Op1, 0, &I);
       if ((*Op0C | RHSKnown.Zero).isAllOnesValue())
         return BinaryOperator::CreateXor(Op1, Op0);
     }