[maglev] Push/Pop Context bytecodes

Bug: v8:7700
Change-Id: I389574d93725fe68816eddbebeef7fbfd3e136fb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3616724
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80297}

src/maglev/maglev-graph-builder.cc

@@ -412,8 +412,17 @@ void MaglevGraphBuilder::VisitMov() {
   MoveNodeBetweenRegisters(iterator_.GetRegisterOperand(0),
                            iterator_.GetRegisterOperand(1));
 }
-MAGLEV_UNIMPLEMENTED_BYTECODE(PushContext)
-MAGLEV_UNIMPLEMENTED_BYTECODE(PopContext)
+
+void MaglevGraphBuilder::VisitPushContext() {
+  MoveNodeBetweenRegisters(interpreter::Register::current_context(),
+                           iterator_.GetRegisterOperand(0));
+  SetContext(GetAccumulatorTagged());
+}
+
+void MaglevGraphBuilder::VisitPopContext() {
+  SetContext(LoadRegisterTagged(0));
+}
+
 MAGLEV_UNIMPLEMENTED_BYTECODE(TestReferenceEqual)
 MAGLEV_UNIMPLEMENTED_BYTECODE(TestUndetectable)
 MAGLEV_UNIMPLEMENTED_BYTECODE(TestNull)

src/maglev/maglev-graph-builder.h

@@ -265,6 +265,11 @@ class MaglevGraphBuilder {
         interpreter::Register::current_context());
   }
 
+  void SetContext(ValueNode* context) {
+    current_interpreter_frame_.set(interpreter::Register::current_context(),
+                                   context);
+  }
+
   FeedbackSlot GetSlotOperand(int operand_index) const {
     return iterator_.GetSlotOperand(operand_index);
   }