[KnownBits] Add wrapper methods for setting and clear all bits in the underlying APInts in KnownBits.

This adds routines for reseting KnownBits to unknown, making the value all zeros or all ones. It also adds methods for querying if the value is zero, all ones or unknown.

Differential Revision: https://reviews.llvm.org/D32637

llvm-svn: 302262

3 files changed, 3 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 4fd90d78a63..6989d67f006 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -3619,7 +3619,7 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
     // then this one is redundant, and should be removed.
     KnownBits Known(1);
     computeKnownBits(IIOperand, Known, 0, II);
-    if (Known.One.isAllOnesValue())
+    if (Known.isAllOnes())
       return eraseInstFromFunction(*II);
 
     // Update the cache of affected values for this assumption (we might be
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 60970775de6..34ce235b3fe 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -4050,7 +4050,7 @@ Instruction *InstCombiner::foldICmpUsingKnownBits(ICmpInst &I) {
     // is set. If the comparison is against zero, then this is a check to see if
     // *that* bit is set.
     APInt Op0KnownZeroInverted = ~Op0Known.Zero;
-    if (~Op1Known.Zero == 0) {
+    if (Op1Known.isZero()) {
       // If the LHS is an AND with the same constant, look through it.
       Value *LHS = nullptr;
       const APInt *LHSC;
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index c42c76addfc..05b01774cd5 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -120,8 +120,7 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
     return nullptr;
   }
 
-  Known.Zero.clearAllBits();
-  Known.One.clearAllBits();
+  Known.resetAll();
   if (DemandedMask == 0)     // Not demanding any bits from V.
     return UndefValue::get(VTy);