[cleanup] Remove V8_REVERSE_JSARGS flag

Change-Id: I2f262f4545de9e421310094d0dfab2f6147869b5
Bug: v8:10201
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2466116Reviewed-by: Junliang Yan <junyan@redhat.com>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70502}

BUILD.gn

@@ -112,9 +112,6 @@ declare_args() {
   # Disable arguments adaptor frame (sets -dV8_NO_ARGUMENTS_ADAPTOR).
   v8_disable_arguments_adaptor = v8_current_cpu == "x64"
 
-  # Reverse JS arguments order in the stack (sets -dV8_REVERSE_JSARGS).
-  v8_enable_reverse_jsargs = true
-
   # Sets -dOBJECT_PRINT.
   v8_enable_object_print = ""
 
@@ -373,10 +370,6 @@ assert(!v8_use_multi_snapshots || !v8_control_flow_integrity,
 assert(!v8_enable_heap_sandbox || v8_enable_pointer_compression,
        "V8 Heap Sandbox requires pointer compression")
 
-assert(
-    !v8_disable_arguments_adaptor || v8_enable_reverse_jsargs,
-    "Disabling the arguments adaptor frame requires reversing the JS arguments stack")
-
 assert(!v8_enable_unconditional_write_barriers || !v8_disable_write_barriers,
        "Write barriers can't be both enabled and disabled")
 
@@ -535,9 +528,6 @@ config("v8_header_features") {
   if (v8_disable_arguments_adaptor) {
     defines += [ "V8_NO_ARGUMENTS_ADAPTOR" ]
   }
-  if (v8_enable_reverse_jsargs) {
-    defines += [ "V8_REVERSE_JSARGS" ]
-  }
 }
 
 # Put defines here that are only used in our internal files and NEVER in

include/v8.h

@@ -11246,22 +11246,14 @@ template<typename T>
 Local<Value> FunctionCallbackInfo<T>::operator[](int i) const {
   // values_ points to the first argument (not the receiver).
   if (i < 0 || length_ <= i) return Local<Value>(*Undefined(GetIsolate()));
-#ifdef V8_REVERSE_JSARGS
   return Local<Value>(reinterpret_cast<Value*>(values_ + i));
-#else
-  return Local<Value>(reinterpret_cast<Value*>(values_ - i));
-#endif
 }
 
 
 template<typename T>
 Local<Object> FunctionCallbackInfo<T>::This() const {
   // values_ points to the first argument (not the receiver).
-#ifdef V8_REVERSE_JSARGS
   return Local<Object>(reinterpret_cast<Object*>(values_ - 1));
-#else
-  return Local<Object>(reinterpret_cast<Object*>(values_ + 1));
-#endif
 }
 
 

infra/mb/mb_config.pyl

@@ -539,7 +539,7 @@
     'debug_x64_trybot': [
       'debug_trybot', 'x64'],
     'debug_x64_reverse_jsargs': [
-      'debug_bot', 'x64', 'reverse_jsargs'],
+      'debug_bot', 'x64'],
     'debug_x64_trybot_custom': [
       'debug_trybot', 'x64', 'v8_snapshot_custom'],
     'full_debug_x64': [
@@ -758,10 +758,6 @@
       'mixins': ['release_bot', 'minimal_symbols', 'dcheck_always_on'],
     },
 
-    'reverse_jsargs': {
-      'gn_args': 'v8_enable_reverse_jsargs=true',
-    },
-
     'official': {
       'gn_args': 'is_official_build=true',
     },

src/builtins/builtins-api.cc

@@ -206,7 +206,6 @@ MaybeHandle<Object> Builtins::InvokeApiFunction(Isolate* isolate,
   } else {
     argv = new Address[frame_argc];
   }
-#ifdef V8_REVERSE_JSARGS
   argv[BuiltinArguments::kNewTargetOffset] = new_target->ptr();
   argv[BuiltinArguments::kTargetOffset] = function->ptr();
   argv[BuiltinArguments::kArgcOffset] = Smi::FromInt(frame_argc).ptr();
@@ -217,19 +216,6 @@ MaybeHandle<Object> Builtins::InvokeApiFunction(Isolate* isolate,
   for (int i = 0; i < argc; ++i) {
     argv[cursor++] = args[i]->ptr();
   }
-#else
-  int cursor = frame_argc - 1;
-  argv[cursor--] = receiver->ptr();
-  for (int i = 0; i < argc; ++i) {
-    argv[cursor--] = args[i]->ptr();
-  }
-  DCHECK_EQ(cursor, BuiltinArguments::kPaddingOffset);
-  argv[BuiltinArguments::kPaddingOffset] =
-      ReadOnlyRoots(isolate).the_hole_value().ptr();
-  argv[BuiltinArguments::kArgcOffset] = Smi::FromInt(frame_argc).ptr();
-  argv[BuiltinArguments::kTargetOffset] = function->ptr();
-  argv[BuiltinArguments::kNewTargetOffset] = new_target->ptr();
-#endif
   MaybeHandle<Object> result;
   {
     RelocatableArguments arguments(isolate, frame_argc, &argv[frame_argc - 1]);

src/builtins/builtins-utils-inl.h

@@ -23,20 +23,12 @@ Handle<Object> BuiltinArguments::atOrUndefined(Isolate* isolate,
 Handle<Object> BuiltinArguments::receiver() const { return at<Object>(0); }
 
 Handle<JSFunction> BuiltinArguments::target() const {
-#ifdef V8_REVERSE_JSARGS
   int index = kTargetOffset;
-#else
-  int index = Arguments::length() - 1 - kTargetOffset;
-#endif
   return Handle<JSFunction>(address_of_arg_at(index));
 }
 
 Handle<HeapObject> BuiltinArguments::new_target() const {
-#ifdef V8_REVERSE_JSARGS
   int index = kNewTargetOffset;
-#else
-  int index = Arguments::length() - 1 - kNewTargetOffset;
-#endif
   return Handle<JSFunction>(address_of_arg_at(index));
 }
 

src/builtins/builtins-utils.h

@@ -52,12 +52,7 @@ class BuiltinArguments : public JavaScriptArguments {
 
   static constexpr int kNumExtraArgs = 4;
   static constexpr int kNumExtraArgsWithReceiver = 5;
-
-#ifdef V8_REVERSE_JSARGS
   static constexpr int kArgsOffset = 4;
-#else
-  static constexpr int kArgsOffset = 0;
-#endif
 
   inline Handle<Object> atOrUndefined(Isolate* isolate, int index) const;
   inline Handle<Object> receiver() const;

src/codegen/arm/macro-assembler-arm.h

@@ -731,11 +731,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // TODO(victorgomes): Remove this function once we stick with the reversed
   // arguments order.
   MemOperand ReceiverOperand(Register argc) {
-#ifdef V8_REVERSE_JSARGS
     return MemOperand(sp, 0);
-#else
-    return MemOperand(sp, argc, LSL, kSystemPointerSizeLog2);
-#endif
   }
 
   // ---------------------------------------------------------------------------

src/codegen/arm64/macro-assembler-arm64.cc

@@ -2186,11 +2186,7 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 }
 
 Operand MacroAssembler::ReceiverOperand(Register arg_count) {
-#ifdef V8_REVERSE_JSARGS
   return Operand(0);
-#else
-  return Operand(arg_count, LSL, kXRegSizeLog2);
-#endif
 }
 
 void MacroAssembler::InvokeFunctionWithNewTarget(

src/codegen/arm64/macro-assembler-arm64.h

@@ -1781,8 +1781,6 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
     DecodeField<Field>(reg, reg);
   }
 
-  // TODO(victorgomes): inline this function once we remove V8_REVERSE_JSARGS
-  // flag.
   Operand ReceiverOperand(const Register arg_count);
 
   // ---- SMI and Number Utilities ----

src/codegen/mips/macro-assembler-mips.h

@@ -913,21 +913,11 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // TODO(victorgomes): Remove this function once we stick with the reversed
   // arguments order.
   void LoadReceiver(Register dest, Register argc) {
-#ifdef V8_REVERSE_JSARGS
     Lw(dest, MemOperand(sp, 0));
-#else
-    Lsa(dest, sp, argc, kPointerSizeLog2);
-    Lw(dest, MemOperand(dest, 0));
-#endif
   }
 
   void StoreReceiver(Register rec, Register argc, Register scratch) {
-#ifdef V8_REVERSE_JSARGS
     Sw(rec, MemOperand(sp, 0));
-#else
-    Lsa(scratch, sp, argc, kPointerSizeLog2);
-    Sw(rec, MemOperand(scratch, 0));
-#endif
   }
 
   // Swap two registers.  If the scratch register is omitted then a slightly