Cleanup StringAddFlags.

src/ia32/code-stubs-ia32.cc

 // Copyright 2012 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 1335 matching lines @@
   // Test if left operand is a string.
   __ JumpIfSmi(left, &call_runtime, Label::kNear);
   __ CmpObjectType(left, FIRST_NONSTRING_TYPE, ecx);
   __ j(above_equal, &call_runtime, Label::kNear);
 
   // Test if right operand is a string.
   __ JumpIfSmi(right, &call_runtime, Label::kNear);
   __ CmpObjectType(right, FIRST_NONSTRING_TYPE, ecx);
   __ j(above_equal, &call_runtime, Label::kNear);
 
-  StringAddStub string_add_stub((StringAddFlags)
-                                (ERECT_FRAME | NO_STRING_CHECK_IN_STUB));
+  StringAddStub string_add_stub(
+      (StringAddFlags)(STRING_ADD_CHECK_NONE | STRING_ADD_ERECT_FRAME));
   GenerateRegisterArgsPush(masm);
   __ TailCallStub(&string_add_stub);
 
   __ bind(&call_runtime);
   GenerateTypeTransition(masm);
 }
 
 
 static void BinaryOpStub_GenerateHeapResultAllocation(MacroAssembler* masm,
                                                       Label* alloc_failure,
@@ skipping 624 matching lines @@
 
   // Registers containing left and right operands respectively.
   Register left = edx;
   Register right = eax;
 
   // Test if left operand is a string.
   __ JumpIfSmi(left, &left_not_string, Label::kNear);
   __ CmpObjectType(left, FIRST_NONSTRING_TYPE, ecx);
   __ j(above_equal, &left_not_string, Label::kNear);
 
-  StringAddStub string_add_left_stub((StringAddFlags)
-      (ERECT_FRAME | NO_STRING_CHECK_LEFT_IN_STUB));
+  StringAddStub string_add_left_stub(
+      (StringAddFlags)(STRING_ADD_CHECK_RIGHT | STRING_ADD_ERECT_FRAME));
   GenerateRegisterArgsPush(masm);
   __ TailCallStub(&string_add_left_stub);
 
   // Left operand is not a string, test right.
   __ bind(&left_not_string);
   __ JumpIfSmi(right, &call_runtime, Label::kNear);
   __ CmpObjectType(right, FIRST_NONSTRING_TYPE, ecx);
   __ j(above_equal, &call_runtime, Label::kNear);
 
-  StringAddStub string_add_right_stub((StringAddFlags)
-      (ERECT_FRAME | NO_STRING_CHECK_RIGHT_IN_STUB));
+  StringAddStub string_add_right_stub(
+      (StringAddFlags)(STRING_ADD_CHECK_LEFT | STRING_ADD_ERECT_FRAME));
   GenerateRegisterArgsPush(masm);
   __ TailCallStub(&string_add_right_stub);
 
   // Neither argument is a string.
   __ bind(&call_runtime);
 }
 
 
 static void BinaryOpStub_GenerateHeapResultAllocation(MacroAssembler* masm,
                                                       Label* alloc_failure,
@@ skipping 3351 matching lines @@
 
 void StringAddStub::Generate(MacroAssembler* masm) {
   Label call_runtime, call_builtin;
   Builtins::JavaScript builtin_id = Builtins::ADD;
 
   // Load the two arguments.
   __ mov(eax, Operand(esp, 2 * kPointerSize));  // First argument.
   __ mov(edx, Operand(esp, 1 * kPointerSize));  // Second argument.
 
   // Make sure that both arguments are strings if not known in advance.
-  if ((flags_ & NO_STRING_ADD_FLAGS) != 0) {
+  // Otherwise, at least one of the arguments is definitely a string,
+  // and we convert the one that is not known to be a string.
+  if ((flags_ & STRING_ADD_CHECK_BOTH) == STRING_ADD_CHECK_BOTH) {

[mvstanton, 2013/07/19 11:44:53]

What about an assert in this case that STRING_ADD_CHECK_LEFT and
STRING_ADD_CHECK_RIGHT are both off.

[Benedikt Meurer, 2013/07/19 11:46:51]

You mean both are on?

[Benedikt Meurer, 2013/07/19 11:52:30]

Done.

     __ JumpIfSmi(eax, &call_runtime);
     __ CmpObjectType(eax, FIRST_NONSTRING_TYPE, ebx);
     __ j(above_equal, &call_runtime);
 
     // First argument is a a string, test second.
     __ JumpIfSmi(edx, &call_runtime);
     __ CmpObjectType(edx, FIRST_NONSTRING_TYPE, ebx);
     __ j(above_equal, &call_runtime);
-  } else {
-    // Here at least one of the arguments is definitely a string.
-    // We convert the one that is not known to be a string.
-    if ((flags_ & NO_STRING_CHECK_LEFT_IN_STUB) == 0) {
-      ASSERT((flags_ & NO_STRING_CHECK_RIGHT_IN_STUB) != 0);
-      GenerateConvertArgument(masm, 2 * kPointerSize, eax, ebx, ecx, edi,
-                              &call_builtin);
-      builtin_id = Builtins::STRING_ADD_RIGHT;
-    } else if ((flags_ & NO_STRING_CHECK_RIGHT_IN_STUB) == 0) {
-      ASSERT((flags_ & NO_STRING_CHECK_LEFT_IN_STUB) != 0);
-      GenerateConvertArgument(masm, 1 * kPointerSize, edx, ebx, ecx, edi,
-                              &call_builtin);
-      builtin_id = Builtins::STRING_ADD_LEFT;
-    }
+  } else if ((flags_ & STRING_ADD_CHECK_LEFT) == STRING_ADD_CHECK_LEFT) {
+    ASSERT((flags_ & STRING_ADD_CHECK_RIGHT) == 0);
+    GenerateConvertArgument(masm, 2 * kPointerSize, eax, ebx, ecx, edi,
+                            &call_builtin);
+    builtin_id = Builtins::STRING_ADD_RIGHT;
+  } else if ((flags_ & STRING_ADD_CHECK_RIGHT) == STRING_ADD_CHECK_RIGHT) {
+    ASSERT((flags_ & STRING_ADD_CHECK_LEFT) == 0);
+    GenerateConvertArgument(masm, 1 * kPointerSize, edx, ebx, ecx, edi,
+                            &call_builtin);
+    builtin_id = Builtins::STRING_ADD_LEFT;
   }
 
   // Both arguments are strings.
   // eax: first string
   // edx: second string
   // Check if either of the strings are empty. In that case return the other.
   Label second_not_zero_length, both_not_zero_length;
   __ mov(ecx, FieldOperand(edx, String::kLengthOffset));
   STATIC_ASSERT(kSmiTag == 0);
   __ test(ecx, ecx);
@@ skipping 265 matching lines @@
   // edi: length of second argument
   StringHelper::GenerateCopyCharacters(masm, ecx, edx, edi, ebx, false);
   __ IncrementCounter(counters->string_add_native(), 1);
   __ ret(2 * kPointerSize);
 
   // Recover stack pointer before jumping to runtime.
   __ bind(&call_runtime_drop_two);
   __ Drop(2);
   // Just jump to runtime to add the two strings.
   __ bind(&call_runtime);
-  if ((flags_ & ERECT_FRAME) != 0) {
+  if ((flags_ & STRING_ADD_ERECT_FRAME) != 0) {
     GenerateRegisterArgsPop(masm, ecx);
     // Build a frame
     {
       FrameScope scope(masm, StackFrame::INTERNAL);
       GenerateRegisterArgsPush(masm);
       __ CallRuntime(Runtime::kStringAdd, 2);
     }
     __ ret(0);
   } else {
     __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
   }
 
   if (call_builtin.is_linked()) {
     __ bind(&call_builtin);
-    if ((flags_ & ERECT_FRAME) != 0) {
+    if ((flags_ & STRING_ADD_ERECT_FRAME) != 0) {
       GenerateRegisterArgsPop(masm, ecx);
       // Build a frame
       {
         FrameScope scope(masm, StackFrame::INTERNAL);
         GenerateRegisterArgsPush(masm);
         __ InvokeBuiltin(builtin_id, CALL_FUNCTION);
       }
       __ ret(0);
     } else {
       __ InvokeBuiltin(builtin_id, JUMP_FUNCTION);
@@ skipping 2061 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32