[CINN] Re-Implement operator = for two Expr Tree (#55145)

* optimize expr operator = implementation

* fix codestyle

paddle/cinn/hlir/framework/op_lowering_util.cc

@@ -825,6 +825,7 @@ bool CanbeInline(Node* node,
   }
 
   auto& op_pattern_dict = Operator::GetAttrs<OpPatternKind>("OpPattern");
+
   for (auto consumer : consumers) {
     if (op_pattern_dict[consumer->op()] == framework::kReduction) {
       return false;

paddle/cinn/ir/ir_visitor.cc

@@ -16,6 +16,7 @@
 
 #include <unordered_set>
 
+#include "paddle/cinn/ir/ir_compare.h"
 #include "paddle/cinn/ir/ir_printer.h"
 #include "paddle/cinn/ir/tensor.h"
 #include "paddle/cinn/utils/string.h"
@@ -25,8 +26,8 @@ namespace ir {
 
 bool operator==(Expr a, Expr b) {
   if (a.get() == b.get()) return true;
-  // TODO(Superjomn) implement with a more accurate one
-  return utils::GetStreamCnt(a) == utils::GetStreamCnt(b);
+  IrEqualVisitor cmp;
+  return cmp.Compare(a, b);
 }
 
 bool operator!=(Expr a, Expr b) { return !(a == b); }

paddle/fluid/framework/paddle2cinn/cinn_compiler.cc

@@ -112,6 +112,7 @@ const CinnCompiledObject &CinnCompiler::Compile(
 
       auto compiled_res =
           CompileGraph(graph, input_tensors, target, compiled_num, stream);
+
       std::unique_lock<std::mutex> guard(lock_);
       // double check cache_by_struct_
       if (!cache_by_struct_.count(cur_key_by_struct)) {