[mips32] Implement V8_REVERSE_JSARGS

Bug: v8:10201
Change-Id: I86cd6b73787cea307013dd311d048b20459ad573
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465052Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70447}

BUILD.gn

@@ -113,8 +113,7 @@ declare_args() {
   v8_disable_arguments_adaptor = false
 
   # Reverse JS arguments order in the stack (sets -dV8_REVERSE_JSARGS).
-  v8_enable_reverse_jsargs =
-      v8_current_cpu != "mipsel" && v8_current_cpu != "mips64el"
+  v8_enable_reverse_jsargs = true
 
   # Sets -dOBJECT_PRINT.
   v8_enable_object_print = ""

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

@@ -4183,6 +4183,33 @@ void TurboAssembler::Push(Smi smi) {
   push(scratch);
 }
 
+void TurboAssembler::PushArray(Register array, Register size, Register scratch,
+                               Register scratch2, PushArrayOrder order) {
+  DCHECK(!AreAliased(array, size, scratch, scratch2));
+  Label loop, entry;
+  if (order == PushArrayOrder::kReverse) {
+    mov(scratch, zero_reg);
+    jmp(&entry);
+    bind(&loop);
+    Lsa(scratch2, array, scratch, kPointerSizeLog2);
+    Lw(scratch2, MemOperand(scratch2));
+    push(scratch2);
+    Addu(scratch, scratch, Operand(1));
+    bind(&entry);
+    Branch(&loop, less, scratch, Operand(size));
+  } else {
+    mov(scratch, size);
+    jmp(&entry);
+    bind(&loop);
+    Lsa(scratch2, array, scratch, kPointerSizeLog2);
+    Lw(scratch2, MemOperand(scratch2));
+    push(scratch2);
+    bind(&entry);
+    Addu(scratch, scratch, Operand(-1));
+    Branch(&loop, greater_equal, scratch, Operand(zero_reg));
+  }
+}
+
 void MacroAssembler::MaybeDropFrames() {
   // Check whether we need to drop frames to restart a function on the stack.
   li(a1, ExternalReference::debug_restart_fp_address(isolate()));
@@ -4351,8 +4378,9 @@ void MacroAssembler::InvokePrologue(Register expected_parameter_count,
                                     Label* done, InvokeFlag flag) {
   Label regular_invoke;
 
-  // Check whether the expected and actual arguments count match. The registers
-  // are set up according to contract with ArgumentsAdaptorTrampoline:
+  // Check whether the expected and actual arguments count match. The
+  // registers are set up according to contract with
+  // ArgumentsAdaptorTrampoline:
   //  a0: actual arguments count
   //  a1: function (passed through to callee)
   //  a2: expected arguments count
@@ -4386,8 +4414,8 @@ void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
 
   {
     // Load receiver to pass it later to DebugOnFunctionCall hook.
-    Lsa(at, sp, actual_parameter_count, kPointerSizeLog2);
-    lw(t0, MemOperand(at));
+    LoadReceiver(t0, actual_parameter_count);
+
     FrameScope frame(this,
                      has_frame() ? StackFrame::NONE : StackFrame::INTERNAL);
     SmiTag(expected_parameter_count);

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

@@ -312,6 +312,10 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
     sw(src, MemOperand(sp, 0));
   }
 
+  enum PushArrayOrder { kNormal, kReverse };
+  void PushArray(Register array, Register size, Register scratch,
+                 Register scratch2, PushArrayOrder order = kNormal);
+
   void SaveRegisters(RegList registers);
   void RestoreRegisters(RegList registers);
 
@@ -905,6 +909,28 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
  public:
   using TurboAssembler::TurboAssembler;
 
+  // It assumes that the arguments are located below the stack pointer.
+  // argc is the number of arguments not including the receiver.
+  // 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
   // less efficient form using xor instead of mov is emitted.
   void Swap(Register reg1, Register reg2, Register scratch = no_reg);