Fast string construct stub (ia32 only for now).

src/ia32/builtins-ia32.cc

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 11 matching lines @@
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "v8.h"
 
 #if defined(V8_TARGET_ARCH_IA32)
 
+#include "code-stubs-ia32.h"
 #include "codegen-inl.h"
 
 namespace v8 {
 namespace internal {
 
 
 #define __ ACCESS_MASM(masm)
 
 
 void Builtins::Generate_Adaptor(MacroAssembler* masm,
@@ skipping 646 matching lines @@
   ParameterCount actual(eax);
   __ SmiUntag(eax);
   __ mov(edi, Operand(ebp, 4 * kPointerSize));
   __ InvokeFunction(edi, actual, CALL_FUNCTION);
 
   __ LeaveInternalFrame();
   __ ret(3 * kPointerSize);  // remove this, receiver, and arguments
 }
 
 
-// Load the built-in Array function from the current context.
-static void GenerateLoadArrayFunction(MacroAssembler* masm, Register result) {
-  // Load the global context.
-  __ mov(result, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
-  __ mov(result, FieldOperand(result, GlobalObject::kGlobalContextOffset));
-  // Load the Array function from the global context.
-  __ mov(result,
-         Operand(result, Context::SlotOffset(Context::ARRAY_FUNCTION_INDEX)));
-}
-
-
 // Number of empty elements to allocate for an empty array.
 static const int kPreallocatedArrayElements = 4;
 
 
 // Allocate an empty JSArray. The allocated array is put into the result
 // register. If the parameter initial_capacity is larger than zero an elements
 // backing store is allocated with this size and filled with the hole values.
 // Otherwise the elements backing store is set to the empty FixedArray.
 static void AllocateEmptyJSArray(MacroAssembler* masm,
                                  Register array_function,
@@ skipping 369 matching lines @@
 
 void Builtins::Generate_ArrayCode(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax : argc
   //  -- esp[0] : return address
   //  -- esp[4] : last argument
   // -----------------------------------
   Label generic_array_code;
 
   // Get the Array function.
-  GenerateLoadArrayFunction(masm, edi);
+  __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, edi);
 
   if (FLAG_debug_code) {
     // Initial map for the builtin Array function shoud be a map.
     __ mov(ebx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
     // Will both indicate a NULL and a Smi.
     __ test(ebx, Immediate(kSmiTagMask));
     __ Assert(not_zero, "Unexpected initial map for Array function");
     __ CmpObjectType(ebx, MAP_TYPE, ecx);
     __ Assert(equal, "Unexpected initial map for Array function");
   }
@@ skipping 15 matching lines @@
   //  -- eax : argc
   //  -- edi : constructor
   //  -- esp[0] : return address
   //  -- esp[4] : last argument
   // -----------------------------------
   Label generic_constructor;
 
   if (FLAG_debug_code) {
     // The array construct code is only set for the builtin Array function which
     // does always have a map.
-    GenerateLoadArrayFunction(masm, ebx);
+    __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, ebx);
     __ cmp(edi, Operand(ebx));
     __ Assert(equal, "Unexpected Array function");
     // Initial map for the builtin Array function should be a map.
     __ mov(ebx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
     // Will both indicate a NULL and a Smi.
     __ test(ebx, Immediate(kSmiTagMask));
     __ Assert(not_zero, "Unexpected initial map for Array function");
     __ CmpObjectType(ebx, MAP_TYPE, ecx);
     __ Assert(equal, "Unexpected initial map for Array function");
   }
 
   // Run the native code for the Array function called as constructor.
   ArrayNativeCode(masm, true, &generic_constructor);
 
   // Jump to the generic construct code in case the specialized code cannot
   // handle the construction.
   __ bind(&generic_constructor);
   Code* code = Builtins::builtin(Builtins::JSConstructStubGeneric);
   Handle<Code> generic_construct_stub(code);
   __ jmp(generic_construct_stub, RelocInfo::CODE_TARGET);
 }
 
 
+void Builtins::Generate_StringConstructCode(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- eax                 : number of arguments
+  //  -- edi                 : constructor function
+  //  -- esp[0]              : return address
+  //  -- esp[(argc - n) * 4] : arg[n] (zero-based)
+  //  -- esp[(argc + 1) * 4] : receiver
+  // -----------------------------------
+  __ IncrementCounter(&Counters::string_ctor_calls, 1);
+
+  if (FLAG_debug_code) {
+    __ LoadGlobalFunction(Context::STRING_FUNCTION_INDEX, ecx);
+    __ cmp(edi, Operand(ecx));
+    __ Assert(equal, "Unexpected String function");
+  }
+
+  // Load the first argument and get rid of the rest (including the
+  // receiver).
+  Label no_arguments;
+  __ test(eax, Operand(eax));
+  __ j(zero, &no_arguments);
+  __ mov(ebx, Operand(esp, eax, times_pointer_size, 0));
+  __ pop(ecx);
+  __ lea(esp, Operand(esp, eax, times_pointer_size, kPointerSize));
+  __ push(ecx);
+  __ mov(eax, ebx);
+
+  // Lookup the argument in the number to string cache.
+  Label not_cached, argument_is_string;
+  NumberToStringStub::GenerateLookupNumberStringCache(
+      masm,
+      eax,  // Input.
+      ebx,  // Result.
+      ecx,  // Scratch 1.
+      edx,  // Scratch 2.
+      false,  // Input is known to be smi?
+      &not_cached);
+  __ IncrementCounter(&Counters::string_ctor_cached_number, 1);
+  __ bind(&argument_is_string);
+  // ----------- S t a t e -------------
+  //  -- ebx    : argument converted to string
+  //  -- edi    : constructor function
+  //  -- esp[0] : return address
+  // -----------------------------------
+
+  // Allocate a JSValue and put the tagged pointer into eax.
+  Label gc_required;
+  __ AllocateInNewSpace(JSValue::kSize,
+                        eax,  // Result.
+                        ecx,  // New allocation top (we ignore it).
+                        no_reg,
+                        &gc_required,
+                        TAG_OBJECT);
+
+  // Set the map.
+  __ LoadGlobalFunctionInitialMap(edi, ecx);

[antonm, 2010/08/26 13:51:16]

maybe add a check under FLAG_debug_code above this line.

+  if (FLAG_debug_code) {
+    __ cmpb(FieldOperand(ecx, Map::kInstanceSizeOffset),
+            JSValue::kSize >> kPointerSizeLog2);
+    __ Assert(equal, "Unexpected string wrapper instance size");
+    __ cmpb(FieldOperand(ecx, Map::kUnusedPropertyFieldsOffset), 0);
+    __ Assert(equal, "Unexpected unused properties of string wrapper");
+  }
+  __ mov(FieldOperand(eax, HeapObject::kMapOffset), ecx);
+
+  // Set properties and elements.
+  __ Set(ecx, Immediate(Factory::empty_fixed_array()));
+  __ mov(FieldOperand(eax, JSObject::kPropertiesOffset), ecx);
+  __ mov(FieldOperand(eax, JSObject::kElementsOffset), ecx);
+
+  // Set the value.
+  __ mov(FieldOperand(eax, JSValue::kValueOffset), ebx);
+
+  // Ensure the object is fully initialized.
+  STATIC_ASSERT(JSValue::kSize == 4 * kPointerSize);
+
+  // We're done. Return.
+  __ ret(0);
+
+  // The argument was not found in the number to string cache. Check
+  // if it's a string already before calling the conversion builtin.
+  Label convert_argument;
+  __ bind(&not_cached);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ test(eax, Immediate(kSmiTagMask));
+  __ j(zero, &convert_argument);
+  Condition is_string = masm->IsObjectStringType(eax, ebx, ecx);
+  __ j(NegateCondition(is_string), &convert_argument);
+  __ mov(ebx, eax);
+  __ IncrementCounter(&Counters::string_ctor_string_value, 1);
+  __ jmp(&argument_is_string);
+
+  // Invoke the conversion builtin and put the result into ebx.
+  __ bind(&convert_argument);
+  __ IncrementCounter(&Counters::string_ctor_conversions, 1);
+  __ EnterInternalFrame();
+  __ push(edi);  // Preserve the function.
+  __ push(eax);
+  __ InvokeBuiltin(Builtins::TO_STRING, CALL_FUNCTION);
+  __ pop(edi);
+  __ LeaveInternalFrame();
+  __ mov(ebx, eax);
+  __ jmp(&argument_is_string);
+
+  // Load the empty string into ebx, remove the receiver from the
+  // stack, and jump back to the case where the argument is a string.
+  __ bind(&no_arguments);
+  __ Set(ebx, Immediate(Factory::empty_string()));
+  __ pop(ecx);
+  __ lea(esp, Operand(esp, kPointerSize));
+  __ push(ecx);
+  __ jmp(&argument_is_string);
+
+  // At this point the argument is already a string. Call runtime to
+  // create a string wrapper.
+  __ bind(&gc_required);
+  __ IncrementCounter(&Counters::string_ctor_gc_required, 1);
+  __ EnterInternalFrame();
+  __ push(ebx);
+  __ CallRuntime(Runtime::kNewStringWrapper, 1);
+  __ LeaveInternalFrame();
+  __ ret(0);
+}
+
+
 static void EnterArgumentsAdaptorFrame(MacroAssembler* masm) {
   __ push(ebp);
   __ mov(ebp, Operand(esp));
 
   // Store the arguments adaptor context sentinel.
   __ push(Immediate(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
 
   // Push the function on the stack.
   __ push(edi);
 
@@ skipping 99 matching lines @@
   __ bind(&dont_adapt_arguments);
   __ jmp(Operand(edx));
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32