[interpreter] Add accumulator use description to bytecodes.

src/interpreter/interpreter-assembler.cc

 // Copyright 2015 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 "src/interpreter/interpreter-assembler.h"
 
 #include <ostream>
 
 #include "src/code-factory.h"
 #include "src/frames.h"
@@ skipping 13 matching lines @@
 InterpreterAssembler::InterpreterAssembler(Isolate* isolate, Zone* zone,
                                            Bytecode bytecode,
                                            OperandScale operand_scale)
     : compiler::CodeStubAssembler(isolate, zone,
                                   InterpreterDispatchDescriptor(isolate),
                                   Code::ComputeFlags(Code::BYTECODE_HANDLER),
                                   Bytecodes::ToString(bytecode), 0),
       bytecode_(bytecode),
       operand_scale_(operand_scale),
       accumulator_(this, MachineRepresentation::kTagged),
+      accumulator_use_(AccumulatorUse::kNone),
       context_(this, MachineRepresentation::kTagged),
       bytecode_array_(this, MachineRepresentation::kTagged),
       disable_stack_check_across_call_(false),
       stack_pointer_before_call_(nullptr) {
   accumulator_.Bind(
       Parameter(InterpreterDispatchDescriptor::kAccumulatorParameter));
   context_.Bind(Parameter(InterpreterDispatchDescriptor::kContextParameter));
   bytecode_array_.Bind(
       Parameter(InterpreterDispatchDescriptor::kBytecodeArrayParameter));
   if (FLAG_trace_ignition) {
     TraceBytecode(Runtime::kInterpreterTraceBytecodeEntry);
   }
 }
 
-InterpreterAssembler::~InterpreterAssembler() {}
+InterpreterAssembler::~InterpreterAssembler() {
+  CHECK_EQ(accumulator_use_, Bytecodes::GetAccumulatorUse(bytecode_));

[rmcilroy, 2016/04/05 12:59:22]

DCHECK_EQ - also please add a comment on how to fix if this fails.

[oth, 2016/04/05 14:12:10]

Comment added and switched to DCHECK though I disagree with the choice.

+}
 
-Node* InterpreterAssembler::GetAccumulator() { return accumulator_.value(); }
+Node* InterpreterAssembler::GetAccumulatorUnchecked() {
+  return accumulator_.value();
+}
+
+Node* InterpreterAssembler::GetAccumulator() {
+  DCHECK(Bytecodes::ReadsAccumulator(bytecode_));
+  accumulator_use_ = accumulator_use_ | AccumulatorUse::kRead;
+  return GetAccumulatorUnchecked();
+}
 
 void InterpreterAssembler::SetAccumulator(Node* value) {
+  DCHECK(Bytecodes::WritesAccumulator(bytecode_));
+  accumulator_use_ = accumulator_use_ | AccumulatorUse::kWrite;
   accumulator_.Bind(value);
 }
 
 Node* InterpreterAssembler::GetContext() { return context_.value(); }
 
 void InterpreterAssembler::SetContext(Node* value) {
   StoreRegister(value, Register::current_context());
   context_.Bind(value);
 }
 
@@ skipping 484 matching lines @@
   DispatchToBytecodeHandler(target_code_object, new_bytecode_offset);
 }
 
 void InterpreterAssembler::DispatchToBytecodeHandler(Node* handler,
                                                      Node* bytecode_offset) {
   if (FLAG_trace_ignition) {
     TraceBytecode(Runtime::kInterpreterTraceBytecodeExit);
   }
 
   InterpreterDispatchDescriptor descriptor(isolate());
-  Node* args[] = {GetAccumulator(),          RegisterFileRawPointer(),
+  Node* args[] = {GetAccumulatorUnchecked(), RegisterFileRawPointer(),
                   bytecode_offset,           BytecodeArrayTaggedPointer(),
                   DispatchTableRawPointer(), GetContext()};
   TailCall(descriptor, handler, args, 0);
 }
 
 void InterpreterAssembler::DispatchWide(OperandScale operand_scale) {
   // Dispatching a wide bytecode requires treating the prefix
   // bytecode a base pointer into the dispatch table and dispatching
   // the bytecode that follows relative to this base.
   //
@@ skipping 79 matching lines @@
   Bind(&no_match);
   Abort(bailout_reason);
   Goto(&end);
   Bind(&match);
   Goto(&end);
   Bind(&end);
 }
 
 void InterpreterAssembler::TraceBytecode(Runtime::FunctionId function_id) {
   CallRuntime(function_id, GetContext(), BytecodeArrayTaggedPointer(),
-              SmiTag(BytecodeOffset()), GetAccumulator());
+              SmiTag(BytecodeOffset()), GetAccumulatorUnchecked());
 }
 
 // static
 bool InterpreterAssembler::TargetSupportsUnalignedAccess() {
 #if V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
   return false;
 #elif V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_PPC
   return CpuFeatures::IsSupported(UNALIGNED_ACCESSES);
 #elif V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_X87 || \
     V8_TARGET_ARCH_S390
   return true;
 #else
 #error "Unknown Architecture"
 #endif
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8