[stubs] Don't unconditionally canonicalize in ChangeFloat64ToTagged.

src/code-stub-assembler.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_CODE_STUB_ASSEMBLER_H_
 #define V8_CODE_STUB_ASSEMBLER_H_
 
 #include <functional>
 
 #include "src/compiler/code-assembler.h"
 #include "src/objects.h"
 
 namespace v8 {
 namespace internal {
 
 class CallInterfaceDescriptor;
 class StatsCounter;
 class StubCache;
 
+enum class CanonicalizationMode { kDontCanonicalize, kCanonicalize };
 enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
 
 enum class UnicodeEncoding {
   // Different unicode encodings in a |word32|:
   UTF16,  // hi 16bits -> trailing surrogate or 0, low 16bits -> lead surrogate
   UTF32,  // full UTF32 code unit / Unicode codepoint
 };
 
 // Provides JavaScript-specific "macro-assembler" functionality on top of the
 // CodeAssembler. By factoring the JavaScript-isms out of the CodeAssembler,
@@ skipping 390 matching lines @@
                                    compiler::Node* allocation_site);
 
   compiler::Node* TruncateTaggedToFloat64(compiler::Node* context,
                                           compiler::Node* value);
   compiler::Node* TruncateTaggedToWord32(compiler::Node* context,
                                          compiler::Node* value);
   // Truncate the floating point value of a HeapNumber to an Int32.
   compiler::Node* TruncateHeapNumberValueToWord32(compiler::Node* object);
 
   // Conversions.
-  compiler::Node* ChangeFloat64ToTagged(compiler::Node* value);
+  // Returns a tagged representation of the float64 {value}. Might optionally
+  // try to canonicalize to Smi representation if the {value} is in Smi range.
+  compiler::Node* ChangeFloat64ToTagged(
+      compiler::Node* value,
+      CanonicalizationMode mode = CanonicalizationMode::kDontCanonicalize);
   compiler::Node* ChangeInt32ToTagged(compiler::Node* value);
   compiler::Node* ChangeUint32ToTagged(compiler::Node* value);
 
   // Type conversions.
   // Throws a TypeError for {method_name} if {value} is not coercible to Object,
   // or returns the {value} converted to a String otherwise.
   compiler::Node* ToThisString(compiler::Node* context, compiler::Node* value,
                                char const* method_name);
   // Throws a TypeError for {method_name} if {value} is neither of the given
   // {primitive_type} nor a JSValue wrapping a value of {primitive_type}, or
@@ skipping 394 matching lines @@
                                            Label* bailout);
 
   static const int kElementLoopUnrollThreshold = 8;
 };
 
 DEFINE_OPERATORS_FOR_FLAGS(CodeStubAssembler::AllocationFlags);
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_CODE_STUB_ASSEMBLER_H_