[ptr-compr][turbofan] Removing LoadStackArgument simplified operator

Going back on https://chromium-review.googlesource.com/c/v8/v8/+/1480382
since now 'tagged' means 'full tagged' again.

I am keeping the access builder since that seems useful to have (as
opposed to building the access builder in the implementation).

Cq-Include-Trybots: luci.v8.try:v8_linux64_pointer_compression_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_linux64_arm64_pointer_compression_rel_ng
Bug: v8:8977, v8:7703, v8:9206
Change-Id: I7c38b090190aa1c3e91c5ab9f729588aeae2dc1b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1594439
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61371}

src/compiler/access-builder.cc

@@ -964,7 +964,7 @@ ElementAccess AccessBuilder::ForStackArgument() {
   ElementAccess access = {
       kUntaggedBase,
       CommonFrameConstants::kFixedFrameSizeAboveFp - kSystemPointerSize,
-      Type::NonInternal(), MachineType::Pointer(),
+      Type::NonInternal(), MachineType::AnyTagged(),
       WriteBarrierKind::kNoWriteBarrier};
   return access;
 }

src/compiler/effect-control-linearizer.cc

@@ -1007,9 +1007,6 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kLoadDataViewElement:
       result = LowerLoadDataViewElement(node);
       break;
-    case IrOpcode::kLoadStackArgument:
-      result = LowerLoadStackArgument(node);
-      break;
     case IrOpcode::kStoreTypedElement:
       LowerStoreTypedElement(node);
       break;
@@ -4527,16 +4524,6 @@ Node* EffectControlLinearizer::LowerLoadDataViewElement(Node* node) {
   return done.PhiAt(0);
 }
 
-Node* EffectControlLinearizer::LowerLoadStackArgument(Node* node) {
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-
-  Node* argument =
-      __ LoadElement(AccessBuilder::ForStackArgument(), base, index);
-
-  return __ BitcastWordToTagged(argument);
-}
-
 void EffectControlLinearizer::LowerStoreDataViewElement(Node* node) {
   ExternalArrayType element_type = ExternalArrayTypeOf(node->op());
   Node* buffer = node->InputAt(0);

src/compiler/effect-control-linearizer.h

@@ -174,7 +174,6 @@ class V8_EXPORT_PRIVATE EffectControlLinearizer {
   Node* LowerLoadFieldByIndex(Node* node);
   Node* LowerLoadTypedElement(Node* node);
   Node* LowerLoadDataViewElement(Node* node);
-  Node* LowerLoadStackArgument(Node* node);
   void LowerStoreTypedElement(Node* node);
   void LowerStoreDataViewElement(Node* node);
   void LowerStoreSignedSmallElement(Node* node);

src/compiler/escape-analysis-reducer.cc

@@ -326,8 +326,9 @@ void EscapeAnalysisReducer::Finalize() {
                                     TypeCache::Get()->kArgumentsLengthType);
             NodeProperties::ReplaceValueInput(load, arguments_frame, 0);
             NodeProperties::ReplaceValueInput(load, offset, 1);
-            NodeProperties::ChangeOp(
-                load, jsgraph()->simplified()->LoadStackArgument());
+            NodeProperties::ChangeOp(load,
+                                     jsgraph()->simplified()->LoadElement(
+                                         AccessBuilder::ForStackArgument()));
             break;
           }
           case IrOpcode::kLoadField: {

src/compiler/escape-analysis-reducer.h

@@ -6,6 +6,7 @@
 #define V8_COMPILER_ESCAPE_ANALYSIS_REDUCER_H_
 
 #include "src/base/compiler-specific.h"
+#include "src/compiler/access-builder.h"
 #include "src/compiler/escape-analysis.h"
 #include "src/compiler/graph-reducer.h"
 #include "src/globals.h"

src/compiler/opcodes.h

@@ -413,7 +413,6 @@
   V(LoadElement)                        \
   V(LoadTypedElement)                   \
   V(LoadDataViewElement)                \
-  V(LoadStackArgument)                  \
   V(StoreField)                         \
   V(StoreElement)                       \
   V(StoreTypedElement)                  \

src/compiler/simplified-lowering.cc

@@ -2821,11 +2821,6 @@ class RepresentationSelector {
                    access.machine_type.representation());
         return;
       }
-      case IrOpcode::kLoadStackArgument: {
-        if (truncation.IsUnused()) return VisitUnused(node);
-        VisitBinop(node, UseInfo::Word(), MachineRepresentation::kTagged);
-        return;
-      }
       case IrOpcode::kStoreElement: {
         ElementAccess access = ElementAccessOf(node->op());
         Node* value_node = node->InputAt(2);

src/compiler/simplified-operator.cc

@@ -1108,17 +1108,6 @@ struct SimplifiedOperatorGlobalCache final {
   };
   LoadFieldByIndexOperator kLoadFieldByIndex;
 
-  struct LoadStackArgumentOperator final : public Operator {
-    LoadStackArgumentOperator()
-        : Operator(                          // --
-              IrOpcode::kLoadStackArgument,  // opcode
-              Operator::kNoDeopt | Operator::kNoThrow |
-                  Operator::kNoWrite,  // flags
-              "LoadStackArgument",     // name
-              2, 1, 1, 1, 1, 0) {}     // counts
-  };
-  LoadStackArgumentOperator kLoadStackArgument;
-
 #define SPECULATIVE_NUMBER_BINOP(Name)                                      \
   template <NumberOperationHint kHint>                                      \
   struct Name##Operator final : public Operator1<NumberOperationHint> {     \
@@ -1711,10 +1700,6 @@ SPECULATIVE_NUMBER_BINOP_LIST(SPECULATIVE_NUMBER_BINOP)
 ACCESS_OP_LIST(ACCESS)
 #undef ACCESS
 
-const Operator* SimplifiedOperatorBuilder::LoadStackArgument() {
-  return &cache_.kLoadStackArgument;
-}
-
 const Operator* SimplifiedOperatorBuilder::TransitionAndStoreElement(
     Handle<Map> double_map, Handle<Map> fast_map) {
   TransitionAndStoreElementParameters parameters(double_map, fast_map);

src/compiler/simplified-operator.h

@@ -809,9 +809,6 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
   // load-element [base + index]
   const Operator* LoadElement(ElementAccess const&);
 
-  // load-stack-argument [base + index]
-  const Operator* LoadStackArgument();
-
   // store-element [base + index], value
   const Operator* StoreElement(ElementAccess const&);
 

src/compiler/typer.cc

@@ -2155,10 +2155,6 @@ Type Typer::Visitor::TypeLoadElement(Node* node) {
   return ElementAccessOf(node->op()).type;
 }
 
-Type Typer::Visitor::TypeLoadStackArgument(Node* node) {
-  return Type::NonInternal();
-}
-
 Type Typer::Visitor::TypeLoadTypedElement(Node* node) {
   switch (ExternalArrayTypeOf(node->op())) {
 #define TYPED_ARRAY_CASE(ElemType, type, TYPE, ctype) \

src/compiler/verifier.cc

@@ -1559,7 +1559,6 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // CheckTypeIs(node, FieldAccessOf(node->op()).type));
       break;
     case IrOpcode::kLoadElement:
-    case IrOpcode::kLoadStackArgument:
       // Object -> elementtype
       // TODO(rossberg): activate once machine ops are typed.
       // CheckValueInputIs(node, 0, Type::Object());

src/machine-type.h

@@ -431,6 +431,7 @@ V8_EXPORT_PRIVATE inline int ElementSizeLog2Of(MachineRepresentation rep) {
     case MachineRepresentation::kTaggedSigned:
     case MachineRepresentation::kTaggedPointer:
     case MachineRepresentation::kTagged:
+      return kSystemPointerSizeLog2;
     case MachineRepresentation::kCompressedSigned:
     case MachineRepresentation::kCompressedPointer:
     case MachineRepresentation::kCompressed: