[TIR][USMP] further changes for extract buffer info

* moved the comparison to a lambda
* lint fixes

Change-Id: If917a3ec12d2a5689eb584e0ac5918a39f9ac12e

Author: manupak

python/tvm/tir/ir_builder.py

@@ -422,7 +422,11 @@ def allocate(self, dtype, shape, name="buf", scope="", pinned_memory=""):
         buffer_var = _expr.Var(name, PointerType(PrimType(dtype), scope))
         if not isinstance(shape, (list, tuple, _container.Array)):
             shape = [shape]
-        self.emit(lambda x: _stmt.Allocate(buffer_var, dtype, shape, const(1, dtype="uint1"), x, pinned_memory))
+        self.emit(
+            lambda x: _stmt.Allocate(
+                buffer_var, dtype, shape, const(1, dtype="uint1"), x, pinned_memory
+            )
+        )
         return BufferVar(self, buffer_var, shape, dtype)
 
     def pointer(self, content_type, name="ptr", scope=""):

src/tir/usmp/analysis/extract_buffer_info.cc

@@ -212,15 +212,6 @@ Map<tir::Stmt, BufferInfo> BufferInfoExtractor::operator()(const PrimFunc& main_
     size_t tick;
     LivenessEventType le_type;
     Allocate allocate;
-    bool operator<(const LivenessEvent& other) {
-      if (tick < other.tick) {
-        return true;
-      } else if (tick == other.tick && le_type == START && other.le_type == END) {
-        return true;
-      }
-      return false;
-    }
-
     bool operator==(const LivenessEvent& other) {
       if (tick == other.tick && le_type == other.le_type && allocate == other.allocate) {
         return true;
@@ -252,7 +243,15 @@ Map<tir::Stmt, BufferInfo> BufferInfoExtractor::operator()(const PrimFunc& main_
     le_events.push_back(le_event_end);
   }
 
-  std::sort(le_events.begin(), le_events.end());
+  std::sort(le_events.begin(), le_events.end(),
+            [](const LivenessEvent& lhs, const LivenessEvent& rhs) {
+              if (lhs.tick < rhs.tick) {
+                return true;
+              } else if (lhs.tick == rhs.tick && lhs.le_type == START && rhs.le_type == END) {
+                return true;
+              }
+              return false;
+            });
   std::unordered_set<Allocate, ObjectPtrHash, ObjectPtrEqual> open_set;
   for (const auto& le_event : le_events) {
     if (le_event.le_type == START) {