[wasm] sundry trap handler fixes

src/compiler/x64/instruction-selector-x64.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 
 #include "src/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
@@ skipping 161 matching lines @@
       return kMode_MR1;
     }
   }
 
   bool CanBeBetterLeftOperand(Node* node) const {
     return !selector()->IsLive(node);
   }
 };
 
 namespace {
-ArchOpcode GetLoadOpcode(LoadRepresentation load_rep, bool protect) {
+ArchOpcode GetLoadOpcode(LoadRepresentation load_rep) {
   ArchOpcode opcode = kArchNop;
   switch (load_rep.representation()) {
     case MachineRepresentation::kFloat32:
       opcode = kX64Movss;
       break;
     case MachineRepresentation::kFloat64:
       opcode = kX64Movsd;
       break;
     case MachineRepresentation::kBit:  // Fall through.
     case MachineRepresentation::kWord8:
@@ skipping 47 matching lines @@
     case MachineRepresentation::kNone:
       UNREACHABLE();
       return kArchNop;
   }
   UNREACHABLE();
   return kArchNop;
 }
 
 }  // namespace
 
 void InstructionSelector::VisitLoad(Node* node) {

[titzer, 2016/12/21 08:51:39]

Looks like VisitLoad and VisitProtectedLoad are now identical except for the
X64MemoryOperation misc field. Collapse into a single routine?

[Eric Holk, 2016/12/22 00:01:44]

Done.

There's also an additional argument to ProtectedLoad for the source position, so
I added that into VisitLoad as well. I kept VisitProtectedLoad as a separate
function that calls VisitLoad because VisitProtectedLoad is automatically
declared by a macro, and perhaps these functions will be more different on
another platform.

   LoadRepresentation load_rep = LoadRepresentationOf(node->op());
   X64OperandGenerator g(this);
 
-  const bool protect = false;
-  ArchOpcode opcode = GetLoadOpcode(load_rep, protect);
+  ArchOpcode opcode = GetLoadOpcode(load_rep);
   InstructionOperand outputs[1];
   outputs[0] = g.DefineAsRegister(node);
   InstructionOperand inputs[3];
   size_t input_count = 0;
   AddressingMode mode =
       g.GetEffectiveAddressMemoryOperand(node, inputs, &input_count);
   InstructionCode code = opcode | AddressingModeField::encode(mode);
   Emit(code, 1, outputs, input_count, inputs);
 }
 
 void InstructionSelector::VisitProtectedLoad(Node* node) {
   LoadRepresentation load_rep = LoadRepresentationOf(node->op());
   X64OperandGenerator g(this);
 
-  const bool protect = true;
-  ArchOpcode opcode = GetLoadOpcode(load_rep, protect);
+  ArchOpcode opcode = GetLoadOpcode(load_rep);
   InstructionOperand outputs[1];
   outputs[0] = g.DefineAsRegister(node);
-  InstructionOperand inputs[4];
+  InstructionOperand inputs[3];
   size_t input_count = 0;
   AddressingMode mode =
       g.GetEffectiveAddressMemoryOperand(node, inputs, &input_count);
-  // Add the context parameter as an input.
-  inputs[input_count++] = g.UseUniqueRegister(node->InputAt(2));
   // Add the source position as an input
-  inputs[input_count++] = g.UseImmediate(node->InputAt(3));
+  inputs[input_count++] = g.UseImmediate(node->InputAt(2));
   InstructionCode code = opcode | AddressingModeField::encode(mode) |
                          MiscField::encode(X64MemoryProtection::kProtected);
   Emit(code, 1, outputs, input_count, inputs);
 }
 
 void InstructionSelector::VisitStore(Node* node) {
   X64OperandGenerator g(this);
   Node* base = node->InputAt(0);
   Node* index = node->InputAt(1);
   Node* value = node->InputAt(2);
@@ skipping 48 matching lines @@
         g.CanBeImmediate(value) ? g.UseImmediate(value) : g.UseRegister(value);
     inputs[input_count++] = value_operand;
     Emit(code, 0, static_cast<InstructionOperand*>(nullptr), input_count,
          inputs);
   }
 }
 
 void InstructionSelector::VisitProtectedStore(Node* node) {
   X64OperandGenerator g(this);
   Node* value = node->InputAt(2);
-  Node* context = node->InputAt(3);
-  Node* position = node->InputAt(4);
+  Node* position = node->InputAt(3);
 
   StoreRepresentation store_rep = StoreRepresentationOf(node->op());
 
   ArchOpcode opcode = GetStoreOpcode(store_rep);
-  InstructionOperand inputs[6];
+  InstructionOperand inputs[5];
   size_t input_count = 0;
   AddressingMode addressing_mode =
       g.GetEffectiveAddressMemoryOperand(node, inputs, &input_count);
   InstructionCode code = opcode | AddressingModeField::encode(addressing_mode) |
                          MiscField::encode(X64MemoryProtection::kProtected);
   InstructionOperand value_operand =
       g.CanBeImmediate(value) ? g.UseImmediate(value) : g.UseRegister(value);
   inputs[input_count++] = value_operand;
-  inputs[input_count++] = g.UseRegister(context);
   inputs[input_count++] = g.UseImmediate(position);
   Emit(code, 0, static_cast<InstructionOperand*>(nullptr), input_count, inputs);
 }
 
 // Architecture supports unaligned access, therefore VisitLoad is used instead
 void InstructionSelector::VisitUnalignedLoad(Node* node) { UNREACHABLE(); }
 
 // Architecture supports unaligned access, therefore VisitStore is used instead
 void InstructionSelector::VisitUnalignedStore(Node* node) { UNREACHABLE(); }
 
@@ skipping 2075 matching lines @@
 // static
 MachineOperatorBuilder::AlignmentRequirements
 InstructionSelector::AlignmentRequirements() {
   return MachineOperatorBuilder::AlignmentRequirements::
       FullUnalignedAccessSupport();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8