[turboshaft] Split out ProtectedLoad and ProtectedStore

Those operators are not eliminable and need different properties than
the rest of loads/stores.

Bug: v8:12783
Change-Id: I7cd478fa827589612ca5d7628c628c09f3f4a3a8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3909361
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83437}

src/compiler/turboshaft/graph-builder.cc

@@ -590,7 +590,6 @@ OpIndex GraphBuilder::Process(
 
     case IrOpcode::kLoad:
     case IrOpcode::kLoadImmutable:
-    case IrOpcode::kProtectedLoad:
     case IrOpcode::kUnalignedLoad: {
       MemoryRepresentation loaded_rep =
           MemoryRepresentation::FromMachineType(LoadRepresentationOf(op));
@@ -598,9 +597,8 @@ OpIndex GraphBuilder::Process(
       Node* base = node->InputAt(0);
       Node* index = node->InputAt(1);
       // It's ok to merge LoadImmutable into Load after scheduling.
-      LoadOp::Kind kind =
-          opcode == IrOpcode::kUnalignedLoad   ? LoadOp::Kind::kRawUnaligned
-          : opcode == IrOpcode::kProtectedLoad ? LoadOp::Kind::kProtected
+      LoadOp::Kind kind = opcode == IrOpcode::kUnalignedLoad
+                              ? LoadOp::Kind::kRawUnaligned
                               : LoadOp::Kind::kRawAligned;
       if (index->opcode() == IrOpcode::kInt32Constant) {
         int32_t offset = OpParameter<int32_t>(index->op());
@@ -618,19 +616,25 @@ OpIndex GraphBuilder::Process(
       return assembler.IndexedLoad(Map(base), Map(index), kind, loaded_rep,
                                    result_rep, offset, element_size_log2);
     }
+    case IrOpcode::kProtectedLoad: {
+      MemoryRepresentation loaded_rep =
+          MemoryRepresentation::FromMachineType(LoadRepresentationOf(op));
+      RegisterRepresentation result_rep = loaded_rep.ToRegisterRepresentation();
+      return assembler.ProtectedLoad(
+          Map(node->InputAt(0)), Map(node->InputAt(1)), loaded_rep, result_rep);
+    }
 
     case IrOpcode::kStore:
-    case IrOpcode::kUnalignedStore:
-    case IrOpcode::kProtectedStore: {
+    case IrOpcode::kUnalignedStore: {
       bool aligned = opcode != IrOpcode::kUnalignedStore;
       StoreRepresentation store_rep =
           aligned ? StoreRepresentationOf(op)
                   : StoreRepresentation(UnalignedStoreRepresentationOf(op),
                                         WriteBarrierKind::kNoWriteBarrier);
-      StoreOp::Kind kind =
-          opcode == IrOpcode::kStore            ? StoreOp::Kind::kRawAligned
-          : opcode == IrOpcode::kUnalignedStore ? StoreOp::Kind::kRawAligned
-                                                : StoreOp::Kind::kProtected;
+      StoreOp::Kind kind = opcode == IrOpcode::kStore
+                               ? StoreOp::Kind::kRawAligned
+                               : StoreOp::Kind::kRawUnaligned;
+
       Node* base = node->InputAt(0);
       Node* index = node->InputAt(1);
       Node* value = node->InputAt(2);
@@ -659,6 +663,12 @@ OpIndex GraphBuilder::Process(
               store_rep.representation()),
           store_rep.write_barrier_kind(), offset, element_size_log2);
     }
+    case IrOpcode::kProtectedStore: {
+      return assembler.ProtectedStore(
+          Map(node->InputAt(0)), Map(node->InputAt(1)), Map(node->InputAt(2)),
+          MemoryRepresentation::FromMachineRepresentation(
+              OpParameter<MachineRepresentation>(node->op())));
+    }
 
     case IrOpcode::kRetain:
       return assembler.Retain(Map(node->InputAt(0)));

src/compiler/turboshaft/operations.h

@@ -77,8 +77,10 @@ class Graph;
   V(Constant)                        \
   V(Load)                            \
   V(IndexedLoad)                     \
+  V(ProtectedLoad)                   \
   V(Store)                           \
   V(IndexedStore)                    \
+  V(ProtectedStore)                  \
   V(Retain)                          \
   V(Parameter)                       \
   V(OsrValue)                        \
@@ -264,6 +266,12 @@ struct OpProperties {
   static constexpr OpProperties BlockTerminatorWithAnySideEffect() {
     return {true, true, true, true};
   }
+  static constexpr OpProperties ReadingAndCanAbort() {
+    return {true, false, true, false};
+  }
+  static constexpr OpProperties WritingAndCanAbort() {
+    return {false, true, true, false};
+  }
   bool operator==(const OpProperties& other) const {
     return can_read == other.can_read && can_write == other.can_write &&
            can_abort == other.can_abort &&
@@ -1265,12 +1273,7 @@ struct ConstantOp : FixedArityOperationT<0, ConstantOp> {
 // When result_rep is RegisterRepresentation::Compressed(), then the load does
 // not decompress the value.
 struct LoadOp : FixedArityOperationT<1, LoadOp> {
-  enum class Kind : uint8_t {
-    kTaggedBase,
-    kRawAligned,
-    kRawUnaligned,
-    kProtected
-  };
+  enum class Kind : uint8_t { kTaggedBase, kRawAligned, kRawUnaligned };
   Kind kind;
   MemoryRepresentation loaded_rep;
   RegisterRepresentation result_rep;
@@ -1303,7 +1306,6 @@ inline bool IsAlignedAccess(LoadOp::Kind kind) {
     case LoadOp::Kind::kRawAligned:
       return true;
     case LoadOp::Kind::kRawUnaligned:
-    case LoadOp::Kind::kProtected:
       return false;
   }
 }
@@ -1347,6 +1349,28 @@ struct IndexedLoadOp : FixedArityOperationT<2, IndexedLoadOp> {
   }
 };
 
+// A protected load registers a trap handler which handles out-of-bounds memory
+// accesses.
+struct ProtectedLoadOp : FixedArityOperationT<2, ProtectedLoadOp> {
+  MemoryRepresentation loaded_rep;
+  RegisterRepresentation result_rep;
+
+  static constexpr OpProperties properties = OpProperties::ReadingAndCanAbort();
+
+  OpIndex base() const { return input(0); }
+  OpIndex index() const { return input(1); }
+
+  ProtectedLoadOp(OpIndex base, OpIndex index, MemoryRepresentation loaded_rep,
+                  RegisterRepresentation result_rep)
+      : Base(base, index), loaded_rep(loaded_rep), result_rep(result_rep) {
+    DCHECK(loaded_rep.ToRegisterRepresentation() == result_rep ||
+           (loaded_rep.IsTagged() &&
+            result_rep == RegisterRepresentation::Compressed()));
+  }
+
+  auto options() const { return std::tuple{loaded_rep, result_rep}; }
+};
+
 // Store `value` to: base + offset.
 // For Kind::tagged_base: subtract kHeapObjectTag,
 //                        `base` has to be the object start.
@@ -1410,6 +1434,23 @@ struct IndexedStoreOp : FixedArityOperationT<3, IndexedStoreOp> {
   }
 };
 
+// A protected store registers a trap handler which handles out-of-bounds memory
+// accesses.
+struct ProtectedStoreOp : FixedArityOperationT<3, ProtectedStoreOp> {
+  MemoryRepresentation stored_rep;
+
+  static constexpr OpProperties properties = OpProperties::WritingAndCanAbort();
+
+  OpIndex base() const { return input(0); }
+  OpIndex index() const { return input(1); }
+  OpIndex value() const { return input(2); }
+
+  ProtectedStoreOp(OpIndex base, OpIndex index, OpIndex value,
+                   MemoryRepresentation stored_rep)
+      : Base(base, index, value), stored_rep(stored_rep) {}
+  auto options() const { return std::tuple{stored_rep}; }
+};
+
 // Retain a HeapObject to prevent it from being garbage collected too early.
 struct RetainOp : FixedArityOperationT<1, RetainOp> {
   OpIndex retained() const { return input(0); }

src/compiler/turboshaft/optimization-phase.h

@@ -463,6 +463,11 @@ struct OptimizationPhase<Analyzer, Assembler>::Impl {
         MapToNewGraph(op.base()), MapToNewGraph(op.index()), op.kind,
         op.loaded_rep, op.result_rep, op.offset, op.element_size_log2);
   }
+  OpIndex ReduceProtectedLoad(const ProtectedLoadOp& op) {
+    return assembler.ProtectedLoad(MapToNewGraph(op.base()),
+                                   MapToNewGraph(op.index()), op.loaded_rep,
+                                   op.result_rep);
+  }
   OpIndex ReduceStore(const StoreOp& op) {
     return assembler.Store(MapToNewGraph(op.base()), MapToNewGraph(op.value()),
                            op.kind, op.stored_rep, op.write_barrier, op.offset);
@@ -473,6 +478,11 @@ struct OptimizationPhase<Analyzer, Assembler>::Impl {
         MapToNewGraph(op.value()), op.kind, op.stored_rep, op.write_barrier,
         op.offset, op.element_size_log2);
   }
+  OpIndex ReduceProtectedStore(const ProtectedStoreOp& op) {
+    return assembler.ProtectedStore(MapToNewGraph(op.base()),
+                                    MapToNewGraph(op.index()),
+                                    MapToNewGraph(op.value()), op.stored_rep);
+  }
   OpIndex ReduceRetain(const RetainOp& op) {
     return assembler.Retain(MapToNewGraph(op.retained()));
   }

src/compiler/turboshaft/recreate-schedule.cc

@@ -930,6 +930,10 @@ Node* ScheduleBuilder::ProcessOperation(const IndexedLoadOp& op) {
                      : machine.ProtectedLoad(loaded_rep),
                  {base, index});
 }
+Node* ScheduleBuilder::ProcessOperation(const ProtectedLoadOp& op) {
+  return AddNode(machine.ProtectedLoad(op.loaded_rep.ToMachineType()),
+                 {GetNode(op.base()), GetNode(op.index())});
+}
 Node* ScheduleBuilder::ProcessOperation(const StoreOp& op) {
   intptr_t offset = op.offset;
   if (op.kind == StoreOp::Kind::kTaggedBase) {
@@ -942,9 +946,6 @@ Node* ScheduleBuilder::ProcessOperation(const StoreOp& op) {
   if (IsAlignedAccess(op.kind)) {
     o = machine.Store(StoreRepresentation(
         op.stored_rep.ToMachineType().representation(), op.write_barrier));
-  } else if (op.kind == LoadOp::Kind::kProtected) {
-    DCHECK_EQ(op.write_barrier, WriteBarrierKind::kNoWriteBarrier);
-    o = machine.ProtectedStore(op.stored_rep.ToMachineType().representation());
   } else {
     DCHECK_EQ(op.write_barrier, WriteBarrierKind::kNoWriteBarrier);
     o = machine.UnalignedStore(op.stored_rep.ToMachineType().representation());
@@ -970,15 +971,17 @@ Node* ScheduleBuilder::ProcessOperation(const IndexedStoreOp& op) {
   if (IsAlignedAccess(op.kind)) {
     o = machine.Store(StoreRepresentation(
         op.stored_rep.ToMachineType().representation(), op.write_barrier));
-  } else if (op.kind == LoadOp::Kind::kProtected) {
-    DCHECK_EQ(op.write_barrier, WriteBarrierKind::kNoWriteBarrier);
-    o = machine.ProtectedStore(op.stored_rep.ToMachineType().representation());
   } else {
     DCHECK_EQ(op.write_barrier, WriteBarrierKind::kNoWriteBarrier);
     o = machine.UnalignedStore(op.stored_rep.ToMachineType().representation());
   }
   return AddNode(o, {base, index, value});
 }
+Node* ScheduleBuilder::ProcessOperation(const ProtectedStoreOp& op) {
+  return AddNode(
+      machine.ProtectedStore(op.stored_rep.ToMachineType().representation()),
+      {GetNode(op.base()), GetNode(op.index()), GetNode(op.value())});
+}
 Node* ScheduleBuilder::ProcessOperation(const RetainOp& op) {
   return AddNode(common.Retain(), {GetNode(op.retained())});
 }