[mips32][heap] Clean-up keys of oldspace weakmaps during scavenge

port https://crrev.com/c/1541476

Original Commit Message:

     This CL adds handling for cleaning up weakmap (EphemeronHashTable)
     keys during scavenge, even if the weakmap resides in oldspace.

Change-Id: If6e06ea8621fd6aff374c04247c3168b2cbb361a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1568712Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Yu Yin <xwafish@gmail.com>
Cr-Commit-Position: refs/heads/master@{#60912}

src/compiler/backend/mips/code-generator-mips.cc

@@ -171,7 +171,9 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
       __ Push(ra);
     }
 
-    if (stub_mode_ == StubCallMode::kCallWasmRuntimeStub) {
+    if (mode_ == RecordWriteMode::kValueIsEphemeronKey) {
+      __ CallEphemeronKeyBarrier(object_, scratch1_, save_fp_mode);
+    } else if (stub_mode_ == StubCallMode::kCallWasmRuntimeStub) {
       // A direct call to a wasm runtime stub defined in this module.
       // Just encode the stub index. This will be patched when the code
       // is added to the native module and copied into wasm code space.

src/mips/interface-descriptors-mips.cc

@@ -61,6 +61,18 @@ void RecordWriteDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
 }
 
+void EphemeronKeyBarrierDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  const Register default_stub_registers[] = {a0, a1, a2, a3, kReturnRegister0};
+
+  data->RestrictAllocatableRegisters(default_stub_registers,
+                                     arraysize(default_stub_registers));
+
+  CHECK_LE(static_cast<size_t>(kParameterCount),
+           arraysize(default_stub_registers));
+  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
+}
+
 const Register FastNewFunctionContextDescriptor::ScopeInfoRegister() {
   return a1;
 }

src/mips/macro-assembler-mips.cc

@@ -251,6 +251,32 @@ void TurboAssembler::RestoreRegisters(RegList registers) {
   MultiPop(regs);
 }
 
+void TurboAssembler::CallEphemeronKeyBarrier(Register object, Register address,
+                                             SaveFPRegsMode fp_mode) {
+  EphemeronKeyBarrierDescriptor descriptor;
+  RegList registers = descriptor.allocatable_registers();
+
+  SaveRegisters(registers);
+
+  Register object_parameter(
+      descriptor.GetRegisterParameter(EphemeronKeyBarrierDescriptor::kObject));
+  Register slot_parameter(descriptor.GetRegisterParameter(
+      EphemeronKeyBarrierDescriptor::kSlotAddress));
+  Register fp_mode_parameter(
+      descriptor.GetRegisterParameter(EphemeronKeyBarrierDescriptor::kFPMode));
+
+  Push(object);
+  Push(address);
+
+  Pop(slot_parameter);
+  Pop(object_parameter);
+
+  Move(fp_mode_parameter, Smi::FromEnum(fp_mode));
+  Call(isolate()->builtins()->builtin_handle(Builtins::kEphemeronKeyBarrier),
+       RelocInfo::CODE_TARGET);
+  RestoreRegisters(registers);
+}
+
 void TurboAssembler::CallRecordWriteStub(
     Register object, Register address,
     RememberedSetAction remembered_set_action, SaveFPRegsMode fp_mode) {

src/mips/macro-assembler-mips.h

@@ -329,6 +329,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void CallRecordWriteStub(Register object, Register address,
                            RememberedSetAction remembered_set_action,
                            SaveFPRegsMode fp_mode, Address wasm_target);
+  void CallEphemeronKeyBarrier(Register object, Register address,
+                               SaveFPRegsMode fp_mode);
 
   // Push multiple registers on the stack.
   // Registers are saved in numerical order, with higher numbered registers