[loong64][wasmfx] Simplify active stack update

zjiaz · V8 LUCI CQ · commit a905bbec0353 · 2025-09-29T23:56:16.000-07:00
Port commit b67ef5a Change-Id: Ie8ff24df7c22e9914b27161095fef175bf47f47f Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6993338 Auto-Submit: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn> Cr-Commit-Position: refs/heads/main@{#102837}
diff --git a/src/builtins/loong64/builtins-loong64.cc b/src/builtins/loong64/builtins-loong64.cc
@@ -3185,12 +3185,9 @@ void ReloadParentStack(MacroAssembler* masm, Register return_reg,
   Register parent = tmp2;
   __ Ld_d(parent, MemOperand(active_stack, wasm::kStackParentOffset));
 
-  // Update active stack.
-  __ StoreRootRelative(IsolateData::active_stack_offset(), parent);
-
   // Switch stack!
-  SwitchStacks(masm, ExternalReference::wasm_return_stack(), active_stack,
-               nullptr, no_reg, {return_reg, return_value, context, parent});
+  SwitchStacks(masm, ExternalReference::wasm_return_stack(), parent, nullptr,
+               no_reg, {return_reg, return_value, context, parent});
   LoadJumpBuffer(masm, parent, false, tmp3);
 }
 
@@ -3425,22 +3422,18 @@ void Builtins::Generate_WasmSuspend(MacroAssembler* masm) {
   ResetWasmJspiFrameStackSlots(masm);
 
   Label resume;
-  DEFINE_REG(stack);
-  __ LoadRootRelative(stack, IsolateData::active_stack_offset());
   DEFINE_REG(scratch);
 
-  // Update active stack.
   DEFINE_REG(parent);
   __ LoadProtectedPointerField(
       parent, FieldMemOperand(suspender, WasmSuspenderObject::kParentOffset));
   DEFINE_REG(target_stack);
   __ LoadExternalPointerField(
       target_stack, FieldMemOperand(parent, WasmSuspenderObject::kStackOffset),
       kWasmStackMemoryTag);
-  __ StoreRootRelative(IsolateData::active_stack_offset(), target_stack);
 
-  SwitchStacks(masm, ExternalReference::wasm_suspend_stack(), stack, &resume,
-               no_reg, {target_stack, suspender, parent});
+  SwitchStacks(masm, ExternalReference::wasm_suspend_stack(), target_stack,
+               &resume, no_reg, {target_stack, suspender, parent});
   __ StoreRootRelative(IsolateData::active_suspender_offset(), parent);
   __ LoadTaggedField(
       kReturnRegister0,
@@ -3512,11 +3505,8 @@ void Generate_WasmResumeHelper(MacroAssembler* masm, wasm::OnResume on_resume) {
       target_stack,
       FieldMemOperand(suspender, WasmSuspenderObject::kStackOffset),
       kWasmStackMemoryTag);
-
-  __ StoreRootRelative(IsolateData::active_stack_offset(), target_stack);
-  SwitchStacks(masm, ExternalReference::wasm_resume_jspi_stack(), active_stack,
+  SwitchStacks(masm, ExternalReference::wasm_resume_jspi_stack(), target_stack,
                &suspend, suspender, {target_stack});
-
   regs.ResetExcept(target_stack);
 
   // -------------------------------------------
@@ -3563,11 +3553,8 @@ void Builtins::Generate_WasmFXResume(MacroAssembler* masm) {
   __ EnterFrame(StackFrame::WASM_STACK_EXIT);
   Register target_stack = WasmFXResumeDescriptor::GetRegisterParameter(0);
   Label suspend;
-  Register active_stack = a0;
-  __ LoadRootRelative(active_stack, IsolateData::active_stack_offset());
-  __ StoreRootRelative(IsolateData::active_stack_offset(), target_stack);
   SwitchStacks(masm, ExternalReference::wasm_resume_wasmfx_stack(),
-               active_stack, &suspend, no_reg, {target_stack});
+               target_stack, &suspend, no_reg, {target_stack});
   LoadJumpBuffer(masm, target_stack, true, a1);
   __ Trap();
   __ bind(&suspend);
@@ -3580,9 +3567,8 @@ void Builtins::Generate_WasmFXReturn(MacroAssembler* masm) {
   __ LoadRootRelative(active_stack, IsolateData::active_stack_offset());
   Register parent = a1;
   __ Move(parent, MemOperand(active_stack, wasm::kStackParentOffset));
-  __ StoreRootRelative(IsolateData::active_stack_offset(), parent);
-  SwitchStacks(masm, ExternalReference::wasm_return_stack(), active_stack,
-               nullptr, no_reg, {parent});
+  SwitchStacks(masm, ExternalReference::wasm_return_stack(), parent, nullptr,
+               no_reg, {parent});
   LoadJumpBuffer(masm, parent, true, a2);
   __ Trap();
 }
@@ -3599,14 +3585,15 @@ void SwitchToAllocatedStack(MacroAssembler* masm, RegisterAllocator& regs,
                             Label* suspend) {
   ResetWasmJspiFrameStackSlots(masm);
   DEFINE_SCOPED(scratch)
-  DEFINE_REG(parent_stack)
-  __ LoadRootRelative(parent_stack, IsolateData::active_stack_offset());
-  __ Ld_d(parent_stack, MemOperand(parent_stack, wasm::kStackParentOffset));
-
-  SwitchStacks(masm, ExternalReference::wasm_start_stack(), parent_stack,
-               suspend, no_reg, {wasm_instance, wrapper_buffer});
+  DEFINE_REG(stack)
+  __ LoadRootRelative(stack, IsolateData::active_suspender_offset());
+  __ LoadExternalPointerField(
+      stack, FieldMemOperand(stack, WasmSuspenderObject::kStackOffset),
+      kWasmStackMemoryTag);
+  SwitchStacks(masm, ExternalReference::wasm_start_stack(), stack, suspend,
+               no_reg, {wasm_instance, wrapper_buffer});
 
-  FREE_REG(parent_stack);
+  FREE_REG(stack);
   // Save the old stack's fp in t0, and use it to access the parameters in
   // the parent frame.
   regs.Pinned(t1, &original_fp);
