[KnownBits] Add zext, sext, and trunc methods to KnownBits

This patch adds zext, sext, and trunc methods to KnownBits and uses them where possible.

Differential Revision: https://reviews.llvm.org/D32784

llvm-svn: 302088

1 files changed, 6 insertions, 12 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index 0195c5e727c..c42c76addfc 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -329,13 +329,11 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
   case Instruction::Trunc: {
     unsigned truncBf = I->getOperand(0)->getType()->getScalarSizeInBits();
     DemandedMask = DemandedMask.zext(truncBf);
-    Known.Zero = Known.Zero.zext(truncBf);
-    Known.One = Known.One.zext(truncBf);
+    Known = Known.zext(truncBf);
     if (SimplifyDemandedBits(I, 0, DemandedMask, Known, Depth + 1))
       return I;
     DemandedMask = DemandedMask.trunc(BitWidth);
-    Known.Zero = Known.Zero.trunc(BitWidth);
-    Known.One = Known.One.trunc(BitWidth);
+    Known = Known.trunc(BitWidth);
     assert(!(Known.Zero & Known.One) && "Bits known to be one AND zero?");
     break;
   }
@@ -365,13 +363,11 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
     unsigned SrcBitWidth =I->getOperand(0)->getType()->getScalarSizeInBits();
 
     DemandedMask = DemandedMask.trunc(SrcBitWidth);
-    Known.Zero = Known.Zero.trunc(SrcBitWidth);
-    Known.One = Known.One.trunc(SrcBitWidth);
+    Known = Known.trunc(SrcBitWidth);
     if (SimplifyDemandedBits(I, 0, DemandedMask, Known, Depth + 1))
       return I;
     DemandedMask = DemandedMask.zext(BitWidth);
-    Known.Zero = Known.Zero.zext(BitWidth);
-    Known.One = Known.One.zext(BitWidth);
+    Known = Known.zext(BitWidth);
     assert(!(Known.Zero & Known.One) && "Bits known to be one AND zero?");
     // The top bits are known to be zero.
     Known.Zero.setBitsFrom(SrcBitWidth);
@@ -391,13 +387,11 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
       InputDemandedBits.setBit(SrcBitWidth-1);
 
     InputDemandedBits = InputDemandedBits.trunc(SrcBitWidth);
-    Known.Zero = Known.Zero.trunc(SrcBitWidth);
-    Known.One = Known.One.trunc(SrcBitWidth);
+    Known = Known.trunc(SrcBitWidth);
     if (SimplifyDemandedBits(I, 0, InputDemandedBits, Known, Depth + 1))
       return I;
     InputDemandedBits = InputDemandedBits.zext(BitWidth);
-    Known.Zero = Known.Zero.zext(BitWidth);
-    Known.One = Known.One.zext(BitWidth);
+    Known = Known.zext(BitWidth);
     assert(!(Known.Zero & Known.One) && "Bits known to be one AND zero?");
 
     // If the sign bit of the input is known set or clear, then we know the