[InstCombine][InstSimplify] Use APInt::isNullValue/isOneValue to reduce compiled code for comparing APInts with 0 and 1. NFC

These methods are specifically optimized to only counting leading zeros without an additional uint64_t compare.

llvm-svn: 304876

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index 5df55f0..0384116 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -121,7 +121,7 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
   }
 
   Known.resetAll();
-  if (DemandedMask == 0)     // Not demanding any bits from V.
+  if (DemandedMask.isNullValue())     // Not demanding any bits from V.
     return UndefValue::get(VTy);
 
   if (Depth == 6)        // Limit search depth.
@@ -488,7 +488,7 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
     // always convert this into a logical shr, even if the shift amount is
     // variable.  The low bit of the shift cannot be an input sign bit unless
     // the shift amount is >= the size of the datatype, which is undefined.
-    if (DemandedMask == 1) {
+    if (DemandedMask.isOneValue()) {
       // Perform the logical shift right.
       Instruction *NewVal = BinaryOperator::CreateLShr(
                         I->getOperand(0), I->getOperand(1), I->getName());
@@ -656,7 +656,7 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
         // If we don't need any of low bits then return zero,
         // we know that DemandedMask is non-zero already.
         APInt DemandedElts = DemandedMask.zextOrTrunc(ArgWidth);
-        if (DemandedElts == 0)
+        if (DemandedElts.isNullValue())
           return ConstantInt::getNullValue(VTy);
 
         // We know that the upper bits are set to zero.
@@ -908,7 +908,7 @@ Value *InstCombiner::SimplifyDemandedVectorElts(Value *V, APInt DemandedElts,
     return nullptr;
   }
 
-  if (DemandedElts == 0) { // If nothing is demanded, provide undef.
+  if (DemandedElts.isNullValue()) { // If nothing is demanded, provide undef.
     UndefElts = EltMask;
     return UndefValue::get(V->getType());
   }