[maglev] Add some debug code to ResumeGenerator

This mimics Ignition, which calls AbortIfRegisterCountInvalid.

This adds a --maglev-assert flag, since we do not want to emit
different code per IR node for debug vs. release modes.

Bug: v8:7700
Change-Id: Iddb17f0ccadf9d6009b242883b2e5d126875c844
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3876385Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83081}

src/flags/flag-definitions.h

@@ -468,6 +468,7 @@ DEFINE_BOOL_READONLY(stress_maglev, false, "trigger maglev compilation earlier")
 #endif  // V8_ENABLE_MAGLEV
 
 DEFINE_STRING(maglev_filter, "*", "optimization filter for the maglev compiler")
+DEFINE_BOOL(maglev_assert, false, "insert extra assertion in maglev code")
 DEFINE_BOOL(maglev_break_on_entry, false, "insert an int3 on maglev entries")
 DEFINE_BOOL(print_maglev_graph, false, "print maglev graph")
 DEFINE_BOOL(print_maglev_code, false, "print maglev code")

src/maglev/maglev-graph-builder.cc

@@ -2927,6 +2927,20 @@ void MaglevGraphBuilder::VisitResumeGenerator() {
   ValueNode* array = AddNewNode<LoadTaggedField>(
       {generator}, JSGeneratorObject::kParametersAndRegistersOffset);
   interpreter::RegisterList registers = iterator_.GetRegisterListOperand(1);
+
+  if (FLAG_maglev_assert) {
+    // Check if register count is invalid, that is, larger than the
+    // register file length.
+    ValueNode* array_length_smi =
+        AddNewNode<LoadTaggedField>({array}, FixedArrayBase::kLengthOffset);
+    ValueNode* array_length = AddNewNode<CheckedSmiUntag>({array_length_smi});
+    ValueNode* register_size = GetInt32Constant(
+        parameter_count_without_receiver() + registers.register_count());
+    AddNewNode<AssertInt32>(
+        {register_size, array_length}, AssertCondition::kLessOrEqual,
+        AbortReason::kInvalidParametersAndRegistersInGenerator);
+  }
+
   const compiler::BytecodeLivenessState* liveness =
       GetOutLivenessFor(next_offset());
   for (int i = 0; i < registers.register_count(); ++i) {

src/maglev/maglev-graph-verifier.h

@@ -213,6 +213,7 @@ class MaglevGraphVerifier {
         CheckValueInputIs(node, 2, ValueRepresentation::kTagged);
         CheckValueInputIs(node, 3, ValueRepresentation::kTagged);
         break;
+      case Opcode::kAssertInt32:
       case Opcode::kInt32AddWithOverflow:
       case Opcode::kInt32SubtractWithOverflow:
       case Opcode::kInt32MultiplyWithOverflow:

src/maglev/maglev-ir.cc

@@ -1157,6 +1157,63 @@ void Abort::PrintParams(std::ostream& os,
   os << "(" << GetAbortReason(reason()) << ")";
 }
 
+namespace {
+Condition ToCondition(AssertCondition cond) {
+  switch (cond) {
+    case AssertCondition::kLess:
+      return less;
+    case AssertCondition::kLessOrEqual:
+      return less_equal;
+    case AssertCondition::kGreater:
+      return greater;
+    case AssertCondition::kGeaterOrEqual:
+      return greater_equal;
+    case AssertCondition::kEqual:
+      return equal;
+    case AssertCondition::kNotEqual:
+      return not_equal;
+  }
+}
+
+std::ostream& operator<<(std::ostream& os, const AssertCondition cond) {
+  switch (cond) {
+    case AssertCondition::kLess:
+      os << "Less";
+      break;
+    case AssertCondition::kLessOrEqual:
+      os << "LessOrEqual";
+      break;
+    case AssertCondition::kGreater:
+      os << "Greater";
+      break;
+    case AssertCondition::kGeaterOrEqual:
+      os << "GeaterOrEqual";
+      break;
+    case AssertCondition::kEqual:
+      os << "Equal";
+      break;
+    case AssertCondition::kNotEqual:
+      os << "NotEqual";
+      break;
+  }
+  return os;
+}
+}  // namespace
+
+void AssertInt32::AllocateVreg(MaglevVregAllocationState* vreg_state) {
+  UseRegister(left_input());
+  UseRegister(right_input());
+}
+void AssertInt32::GenerateCode(MaglevAssembler* masm,
+                               const ProcessingState& state) {
+  __ cmpq(ToRegister(left_input()), ToRegister(right_input()));
+  __ Check(ToCondition(condition_), reason_);
+}
+void AssertInt32::PrintParams(std::ostream& os,
+                              MaglevGraphLabeller* graph_labeller) const {
+  os << "(" << condition_ << ")";
+}
+
 void CheckMaps::AllocateVreg(MaglevVregAllocationState* vreg_state) {
   UseRegister(receiver_input());
 }

src/maglev/maglev-ir.h

@@ -184,6 +184,7 @@ class CompactInterpreterFrameState;
   V(GapMove)
 
 #define NODE_LIST(V)                  \
+  V(AssertInt32)                      \
   V(CheckMaps)                        \
   V(CheckSmi)                         \
   V(CheckNumber)                      \
@@ -2455,6 +2456,33 @@ class CreateClosure : public FixedInputValueNodeT<1, CreateClosure> {
   const bool pretenured_;
 };
 
+enum class AssertCondition {
+  kLess,
+  kLessOrEqual,
+  kGreater,
+  kGeaterOrEqual,
+  kEqual,
+  kNotEqual,
+};
+
+class AssertInt32 : public FixedInputNodeT<2, AssertInt32> {
+  using Base = FixedInputNodeT<2, AssertInt32>;
+
+ public:
+  explicit AssertInt32(uint64_t bitfield, AssertCondition condition,
+                       AbortReason reason)
+      : Base(bitfield), condition_(condition), reason_(reason) {}
+
+  Input& left_input() { return input(0); }
+  Input& right_input() { return input(1); }
+
+  DECL_NODE_INTERFACE()
+
+ private:
+  AssertCondition condition_;
+  AbortReason reason_;
+};
+
 enum class CheckType { kCheckHeapObject, kOmitHeapObjectCheck };
 
 class CheckMaps : public FixedInputNodeT<1, CheckMaps> {