review: small clarifications

- use MapT instead of IMap
- use ~0u for conciseness

Author: inbelic

llvm/include/llvm/Frontend/HLSL/HLSLRootSignatureUtils.h

@@ -63,22 +63,22 @@ class MetadataBuilder {
 // RangeInfo holds the information to correctly construct a ResourceRange
 // and retains this information to be used for displaying a better diagnostic
 struct RangeInfo {
-  const static uint32_t Unbounded = static_cast<uint32_t>(-1);
+  const static uint32_t Unbounded = ~0u;
 
   uint32_t LowerBound;
   uint32_t UpperBound;
 };
 
 class ResourceRange {
 public:
-  using IMap = llvm::IntervalMap<uint32_t, const RangeInfo *, 16,
+  using MapT = llvm::IntervalMap<uint32_t, const RangeInfo *, 16,
                                  llvm::IntervalMapInfo<uint32_t>>;
 
 private:
-  IMap Intervals;
+  MapT Intervals;
 
 public:
-  ResourceRange(IMap::Allocator &Allocator) : Intervals(IMap(Allocator)) {}
+  ResourceRange(MapT::Allocator &Allocator) : Intervals(MapT(Allocator)) {}
 
   // Returns a reference to the first RangeInfo that overlaps with
   // [Info.LowerBound;Info.UpperBound], or, std::nullopt if there is no overlap

llvm/lib/Frontend/HLSL/HLSLRootSignatureUtils.cpp

@@ -324,7 +324,7 @@ MDNode *MetadataBuilder::BuildStaticSampler(const StaticSampler &Sampler) {
 
 std::optional<const RangeInfo *>
 ResourceRange::getOverlapping(const RangeInfo &Info) const {
-  IMap::const_iterator Interval = Intervals.find(Info.LowerBound);
+  MapT::const_iterator Interval = Intervals.find(Info.LowerBound);
   if (!Interval.valid() || Info.UpperBound < Interval.start())
     return std::nullopt;
   return Interval.value();
@@ -339,7 +339,7 @@ std::optional<const RangeInfo *> ResourceRange::insert(const RangeInfo &Info) {
   uint32_t UpperBound = Info.UpperBound;
 
   std::optional<const RangeInfo *> Res = std::nullopt;
-  IMap::iterator Interval = Intervals.begin();
+  MapT::iterator Interval = Intervals.begin();
 
   while (true) {
     if (UpperBound < LowerBound)