[stubs] Improve code generation for ToBoolean.

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"
@@ skipping 81 matching lines @@
   compiler::Node* InnerAllocate(compiler::Node* previous,
                                 compiler::Node* offset);
 
   void Assert(compiler::Node* condition);
 
   // Check a value for smi-ness
   compiler::Node* WordIsSmi(compiler::Node* a);
   // Check that the value is a positive smi.
   compiler::Node* WordIsPositiveSmi(compiler::Node* a);
 
+  void BranchIfSmiEqual(compiler::Node* a, compiler::Node* b, Label* if_true,
+                        Label* if_false) {
+    BranchIf(SmiEqual(a, b), if_true, if_false);
+  }
+
   void BranchIfSmiLessThan(compiler::Node* a, compiler::Node* b, Label* if_true,
                            Label* if_false) {
     BranchIf(SmiLessThan(a, b), if_true, if_false);
   }
 
   void BranchIfSmiLessThanOrEqual(compiler::Node* a, compiler::Node* b,
                                   Label* if_true, Label* if_false) {
     BranchIf(SmiLessThanOrEqual(a, b), if_true, if_false);
   }
 
   void BranchIfFloat64IsNaN(compiler::Node* value, Label* if_true,
                             Label* if_false) {
     BranchIfFloat64Equal(value, value, if_false, if_true);
   }
 
+  // Branches to {if_true} if ToBoolean applied to {value} yields true,
+  // otherwise goes to {if_false}.
+  void BranchIfToBooleanIsTrue(compiler::Node* value, Label* if_true,
+                               Label* if_false);
+
   // Load value from current frame by given offset in bytes.
   compiler::Node* LoadFromFrame(int offset,
                                 MachineType rep = MachineType::AnyTagged());
   // Load value from current parent frame by given offset in bytes.
   compiler::Node* LoadFromParentFrame(
       int offset, MachineType rep = MachineType::AnyTagged());
 
   // Load an object pointer from a buffer that isn't in the heap.
   compiler::Node* LoadBufferObject(compiler::Node* buffer, int offset,
                                    MachineType rep = MachineType::AnyTagged());
@@ skipping 350 matching lines @@
                                        AllocationFlags flags,
                                        compiler::Node* top_adddress,
                                        compiler::Node* limit_address);
 
   static const int kElementLoopUnrollThreshold = 8;
 };
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_CODE_STUB_ASSEMBLER_H_