[stubs] Improve code generation for ToBoolean.

src/builtins/builtins.cc

 // Copyright 2012 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.
 
 #include "src/builtins/builtins.h"
 #include "src/builtins/builtins-utils.h"
 
 #include "src/api-arguments.h"
 #include "src/api-natives.h"
 #include "src/base/ieee754.h"
@@ skipping 5252 matching lines @@
       // Note: We cannot tail call to the runtime here, as js-to-wasm
       // trampolines also use this code currently, and they declare all
       // outgoing parameters as untagged, while we would push a tagged
       // object here.
       Node* result = assembler->CallRuntime(Runtime::kToNumber, context, input);
       assembler->Return(result);
     }
   }
 }
 
+// ES6 section 7.1.2 ToBoolean ( argument )
+void Builtins::Generate_ToBoolean(CodeStubAssembler* assembler) {
+  typedef compiler::Node Node;
+  typedef CodeStubAssembler::Label Label;
+
+  Node* value = assembler->Parameter(0);
+
+  Label return_true(assembler), return_false(assembler);
+  assembler->BranchIfToBooleanIsTrue(value, &return_true, &return_false);
+
+  assembler->Bind(&return_true);
+  assembler->Return(assembler->BooleanConstant(true));
+
+  assembler->Bind(&return_false);
+  assembler->Return(assembler->BooleanConstant(false));
+}
+
 void Builtins::Generate_KeyedStoreIC_Slow(MacroAssembler* masm) {
   ElementHandlerCompiler::GenerateStoreSlow(masm);
 }
 
 void Builtins::Generate_StoreIC_Setter_ForDeopt(MacroAssembler* masm) {
   NamedStoreHandlerCompiler::GenerateStoreViaSetterForDeopt(masm);
 }
 
 void Builtins::Generate_KeyedStoreIC_Megamorphic(MacroAssembler* masm) {
   KeyedStoreIC::GenerateMegamorphic(masm, SLOPPY);
@@ skipping 549 matching lines @@
 #define DEFINE_BUILTIN_ACCESSOR(Name, ...)                                    \
   Handle<Code> Builtins::Name() {                                             \
     Code** code_address = reinterpret_cast<Code**>(builtin_address(k##Name)); \
     return Handle<Code>(code_address);                                        \
   }
 BUILTIN_LIST_ALL(DEFINE_BUILTIN_ACCESSOR)
 #undef DEFINE_BUILTIN_ACCESSOR
 
 }  // namespace internal
 }  // namespace v8