[ConstantRange] Add getFull() + getEmpty() named constructors; NFC

This adds ConstantRange::getFull(BitWidth) and
ConstantRange::getEmpty(BitWidth) named constructors as more readable
alternatives to the current ConstantRange(BitWidth, /* full */ false)
and similar. Additionally private getFull() and getEmpty() member
functions are added which return a full/empty range with the same bit
width -- these are commonly needed inside ConstantRange.cpp.

The IsFullSet argument in the ConstantRange(BitWidth, IsFullSet)
constructor is now mandatory for the few usages that still make use of it.

Differential Revision: https://reviews.llvm.org/D59716

llvm-svn: 356852

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Scalar/Float2Int.cpp b/llvm/lib/Transforms/Scalar/Float2Int.cpp
index 4a1275d3661..cb0288a28f7 100644
--- a/llvm/lib/Transforms/Scalar/Float2Int.cpp
+++ b/llvm/lib/Transforms/Scalar/Float2Int.cpp
@@ -147,10 +147,10 @@ void Float2IntPass::seen(Instruction *I, ConstantRange R) {
 
 // Helper - get a range representing a poison value.
 ConstantRange Float2IntPass::badRange() {
-  return ConstantRange(MaxIntegerBW + 1, true);
+  return ConstantRange::getFull(MaxIntegerBW + 1);
 }
 ConstantRange Float2IntPass::unknownRange() {
-  return ConstantRange(MaxIntegerBW + 1, false);
+  return ConstantRange::getEmpty(MaxIntegerBW + 1);
 }
 ConstantRange Float2IntPass::validateRange(ConstantRange R) {
   if (R.getBitWidth() > MaxIntegerBW + 1)
@@ -194,7 +194,7 @@ void Float2IntPass::walkBackwards(const SmallPtrSetImpl<Instruction*> &Roots) {
       // Path terminated cleanly - use the type of the integer input to seed
       // the analysis.
       unsigned BW = I->getOperand(0)->getType()->getPrimitiveSizeInBits();
-      auto Input = ConstantRange(BW, true);
+      auto Input = ConstantRange::getFull(BW);
       auto CastOp = (Instruction::CastOps)I->getOpcode();
       seen(I, validateRange(Input.castOp(CastOp, MaxIntegerBW+1)));
       continue;