[interpreter] Add a register operand to ToNumber

ToNumber's result is always directly stored to a register using a Star
bytecode. Fuse it into ToNumber.

BUG=v8:4280
LOG=n

Review-Url: https://codereview.chromium.org/2165953002
Cr-Commit-Position: refs/heads/master@{#37976}

src/compiler/bytecode-graph-builder.cc

@@ -1319,7 +1319,11 @@ void BytecodeGraphBuilder::VisitToObject() {
 }
 
 void BytecodeGraphBuilder::VisitToNumber() {
-  BuildCastOperator(javascript()->ToNumber());
+  FrameStateBeforeAndAfter states(this);
+  Node* value =
+      NewNode(javascript()->ToNumber(), environment()->LookupAccumulator());
+  environment()->BindRegister(bytecode_iterator().GetRegisterOperand(0), value,
+                              &states);
 }
 
 void BytecodeGraphBuilder::VisitJump() { BuildJump(); }

src/interpreter/bytecode-array-builder.cc

@@ -387,8 +387,9 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::CastAccumulatorToName() {
   return *this;
 }
 
-BytecodeArrayBuilder& BytecodeArrayBuilder::CastAccumulatorToNumber() {
-  Output(Bytecode::kToNumber);
+BytecodeArrayBuilder& BytecodeArrayBuilder::CastAccumulatorToNumber(
+    Register out) {
+  Output(Bytecode::kToNumber, RegisterOperand(out));
   return *this;
 }
 

src/interpreter/bytecode-array-builder.h

@@ -215,7 +215,8 @@ class BytecodeArrayBuilder final : public ZoneObject {
   BytecodeArrayBuilder& CastAccumulatorToBoolean();
   BytecodeArrayBuilder& CastAccumulatorToJSObject();
   BytecodeArrayBuilder& CastAccumulatorToName();
-  BytecodeArrayBuilder& CastAccumulatorToNumber();
+  // Does not update the accumulator but stores to |out| instead.
+  BytecodeArrayBuilder& CastAccumulatorToNumber(Register out);
 
   // Flow Control.
   BytecodeArrayBuilder& Bind(BytecodeLabel* label);

src/interpreter/bytecode-generator.cc

@@ -2790,7 +2790,7 @@ void BytecodeGenerator::VisitCountOperation(CountOperation* expr) {
     old_value = register_allocator()->outer()->NewRegister();
 
     // Convert old value into a number before saving it.
-    builder()->CastAccumulatorToNumber().StoreAccumulatorInRegister(old_value);
+    builder()->CastAccumulatorToNumber(old_value);
   }
 
   // Perform +1/-1 operation.

src/interpreter/bytecodes.h

@@ -212,7 +212,7 @@ namespace interpreter {
                                                                                \
   /* Cast operators */                                                         \
   V(ToName, AccumulatorUse::kReadWrite)                                        \
-  V(ToNumber, AccumulatorUse::kReadWrite)                                      \
+  V(ToNumber, AccumulatorUse::kRead, OperandType::kRegOut)                     \
   V(ToObject, AccumulatorUse::kReadWrite)                                      \
                                                                                \
   /* Literals */                                                               \

src/interpreter/interpreter.cc

@@ -997,13 +997,17 @@ void Interpreter::DoShiftRightSmi(InterpreterAssembler* assembler) {
   __ Dispatch();
 }
 
-void Interpreter::DoUnaryOp(Callable callable,
+Node* Interpreter::BuildUnaryOp(Callable callable,
                                 InterpreterAssembler* assembler) {
   Node* target = __ HeapConstant(callable.code());
   Node* accumulator = __ GetAccumulator();
   Node* context = __ GetContext();
-  Node* result =
-      __ CallStub(callable.descriptor(), target, context, accumulator);
+  return __ CallStub(callable.descriptor(), target, context, accumulator);
+}
+
+void Interpreter::DoUnaryOp(Callable callable,
+                            InterpreterAssembler* assembler) {
+  Node* result = BuildUnaryOp(callable, assembler);
   __ SetAccumulator(result);
   __ Dispatch();
 }
@@ -1028,7 +1032,9 @@ void Interpreter::DoToName(InterpreterAssembler* assembler) {
 //
 // Cast the object referenced by the accumulator to a number.
 void Interpreter::DoToNumber(InterpreterAssembler* assembler) {
-  DoUnaryOp(CodeFactory::ToNumber(isolate_), assembler);
+  Node* result = BuildUnaryOp(CodeFactory::ToNumber(isolate_), assembler);
+  __ StoreRegister(result, __ BytecodeOperandReg(0));
+  __ Dispatch();
 }
 
 // ToObject

src/interpreter/interpreter.h

@@ -79,7 +79,8 @@ class Interpreter {
   template <class Generator>
   void DoBinaryOpWithImmediate(InterpreterAssembler* assembler);
 
-  // Generates code to perform the unary operation via |callable|.
+  // Generates code to perform the unary operation via |callable| and stores
+  // the result to the accumulator.
   void DoUnaryOp(Callable callable, InterpreterAssembler* assembler);
 
   // Generates code to perform the unary operation via |Generator|.
@@ -152,6 +153,10 @@ class Interpreter {
                                compiler::Node* cache_length,
                                InterpreterAssembler* assembler);
 
+  // Generates code to perform the unary operation via |callable|.
+  compiler::Node* BuildUnaryOp(Callable callable,
+                               InterpreterAssembler* assembler);
+
   uintptr_t GetDispatchCounter(Bytecode from, Bytecode to) const;
 
   // Get dispatch table index of bytecode.

test/cctest/interpreter/bytecode_expectations/AssignmentsInBinaryExpression.golden

@@ -99,7 +99,7 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 29
+bytecode array length: 28
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), U8(55),
@@ -112,8 +112,7 @@ bytecodes: [
                 B(Star), R(0),
   /*   68 E> */ B(Add), R(2),
                 B(Star), R(0),
-  /*   75 S> */ B(ToNumber),
-                B(Star), R(1),
+  /*   75 S> */ B(ToNumber), R(1),
                 B(Inc),
                 B(Star), R(0),
   /*   80 S> */ B(Nop),
@@ -246,7 +245,7 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 37
+bytecode array length: 36
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), U8(17),
@@ -257,8 +256,7 @@ bytecodes: [
   /*   57 E> */ B(Add), R(1),
                 B(Star), R(2),
                 B(Ldar), R(0),
-                B(ToNumber),
-                B(Star), R(1),
+                B(ToNumber), R(1),
                 B(Inc),
                 B(Star), R(0),
                 B(Ldar), R(1),

test/cctest/interpreter/bytecode_expectations/BasicLoops.golden

@@ -681,13 +681,13 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 119
+bytecode array length: 118
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(1),
   /*   52 S> */ B(Ldar), R(1),
-                B(JumpIfToBooleanFalse), U8(111),
+                B(JumpIfToBooleanFalse), U8(110),
   /*   45 E> */ B(StackCheck),
                 B(LdaConstant), U8(0),
                 B(Star), R(4),
@@ -714,14 +714,13 @@ bytecodes: [
                 B(JumpIfToBooleanFalse), U8(8),
   /*  113 S> */ B(PopContext), R(3),
                 B(PopContext), R(3),
-                B(Jump), U8(43),
+                B(Jump), U8(42),
   /*  126 S> */ B(LdaContextSlot), R(context), U8(4),
                 B(JumpIfNotHole), U8(11),
                 B(LdaConstant), U8(3),
                 B(Star), R(4),
                 B(CallRuntime), U16(Runtime::kThrowReferenceError), R(4), U8(1),
-                B(ToNumber),
-                B(Star), R(4),
+                B(ToNumber), R(4),
                 B(Inc),
                 B(Star), R(5),
   /*  127 E> */ B(LdaContextSlot), R(context), U8(4),
@@ -732,7 +731,7 @@ bytecodes: [
                 B(Ldar), R(5),
                 B(StaContextSlot), R(context), U8(4),
                 B(PopContext), R(3),
-                B(Jump), U8(-111),
+                B(Jump), U8(-110),
                 B(LdaUndefined),
   /*  137 S> */ B(Return),
 ]

test/cctest/interpreter/bytecode_expectations/CountOperators.golden

@@ -33,13 +33,12 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 14
+bytecode array length: 13
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), U8(1),
                 B(Star), R(0),
-  /*   45 S> */ B(ToNumber),
-                B(Star), R(1),
+  /*   45 S> */ B(ToNumber), R(1),
                 B(Inc),
                 B(Star), R(0),
                 B(Ldar), R(1),
@@ -76,13 +75,12 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 14
+bytecode array length: 13
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), U8(1),
                 B(Star), R(0),
-  /*   45 S> */ B(ToNumber),
-                B(Star), R(1),
+  /*   45 S> */ B(ToNumber), R(1),
                 B(Dec),
                 B(Star), R(0),
                 B(Ldar), R(1),
@@ -99,15 +97,14 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 24
+bytecode array length: 23
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(1),
                 B(Star), R(1),
                 B(Star), R(0),
   /*   54 S> */ B(LdaNamedProperty), R(0), U8(1), U8(1),
-                B(ToNumber),
-                B(Star), R(2),
+                B(ToNumber), R(2),
                 B(Inc),
   /*   66 E> */ B(StaNamedPropertySloppy), R(0), U8(1), U8(3),
                 B(Ldar), R(2),
@@ -150,7 +147,7 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 29
+bytecode array length: 28
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   45 S> */ B(LdaConstant), U8(0),
@@ -160,8 +157,7 @@ bytecodes: [
                 B(Star), R(1),
   /*   72 S> */ B(Ldar), R(0),
   /*   81 E> */ B(LdaKeyedProperty), R(1), U8(1),
-                B(ToNumber),
-                B(Star), R(4),
+                B(ToNumber), R(4),
                 B(Dec),
   /*   86 E> */ B(StaKeyedPropertySloppy), R(1), R(0), U8(3),
                 B(Ldar), R(4),
@@ -233,7 +229,7 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 31
+bytecode array length: 30
 bytecodes: [
                 B(CallRuntime), U16(Runtime::kNewFunctionContext), R(closure), U8(1),
                 B(PushContext), R(1),
@@ -243,8 +239,7 @@ bytecodes: [
   /*   53 S> */ B(CreateClosure), U8(0), U8(2),
                 B(Star), R(0),
   /*   78 S> */ B(LdaContextSlot), R(context), U8(4),
-                B(ToNumber),
-                B(Star), R(2),
+                B(ToNumber), R(2),
                 B(Dec),
   /*   86 E> */ B(StaContextSlot), R(context), U8(4),
                 B(Ldar), R(2),
@@ -262,7 +257,7 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 26
+bytecode array length: 25
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   44 S> */ B(LdaSmi), U8(1),
@@ -270,8 +265,7 @@ bytecodes: [
   /*   55 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(3),
                 B(Star), R(1),
   /*   63 S> */ B(Ldar), R(0),
-                B(ToNumber),
-                B(Star), R(3),
+                B(ToNumber), R(3),
                 B(Inc),
                 B(Star), R(0),
                 B(LdaSmi), U8(2),

test/cctest/interpreter/bytecode_expectations/GlobalCountOperators.golden

@@ -38,12 +38,11 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
   /*   26 E> */ B(StackCheck),
   /*   31 S> */ B(LdaGlobal), U8(1),
-                B(ToNumber),
-                B(Star), R(0),
+                B(ToNumber), R(0),
                 B(Dec),
   /*   44 E> */ B(StaGlobalSloppy), U8(0), U8(3),
                 B(Ldar), R(0),
@@ -85,12 +84,11 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
   /*   27 E> */ B(StackCheck),
   /*   32 S> */ B(LdaGlobal), U8(1),
-                B(ToNumber),
-                B(Star), R(0),
+                B(ToNumber), R(0),
                 B(Inc),
   /*   50 E> */ B(StaGlobalSloppy), U8(0), U8(3),
                 B(Ldar), R(0),

test/cctest/interpreter/bytecode_expectations/JumpsRequiringConstantWideOperands.golden

@@ -329,7 +329,7 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 1410
+bytecode array length: 1409
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
@@ -960,7 +960,7 @@ bytecodes: [
                 B(Star), R(1),
   /* 4108 S> */ B(LdaSmi), U8(3),
   /* 4108 E> */ B(TestLessThan), R(1),
-                B(Wide), B(JumpIfFalse), U16(38),
+                B(Wide), B(JumpIfFalse), U16(37),
   /* 4090 E> */ B(StackCheck),
   /* 4122 S> */ B(LdaSmi), U8(1),
   /* 4128 E> */ B(TestEqual), R(1),
@@ -969,13 +969,12 @@ bytecodes: [
   /* 4146 S> */ B(LdaSmi), U8(2),
   /* 4152 E> */ B(TestEqual), R(1),
                 B(Wide), B(JumpIfFalse), U16(7),
-  /* 4158 S> */ B(Wide), B(Jump), U16(13),
+  /* 4158 S> */ B(Wide), B(Jump), U16(12),
   /* 4114 S> */ B(Ldar), R(1),
-                B(ToNumber),
-                B(Star), R(2),
+                B(ToNumber), R(2),
                 B(Inc),
                 B(Star), R(1),
-                B(Jump), U8(-41),
+                B(Jump), U8(-40),
   /* 4167 S> */ B(LdaSmi), U8(3),
   /* 4177 S> */ B(Return),
 ]

test/cctest/interpreter/bytecode_expectations/WideRegisters.golden

@@ -893,7 +893,7 @@ snippet: "
 "
 frame size: 158
 parameter count: 1
-bytecode array length: 56
+bytecode array length: 55
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /* 1503 S> */ B(LdaZero),
@@ -904,18 +904,17 @@ bytecodes: [
                 B(Wide), B(Star), R16(128),
   /* 1538 S> */ B(LdaSmi), U8(64),
   /* 1538 E> */ B(Wide), B(TestLessThan), R16(128),
-                B(JumpIfFalse), U8(33),
+                B(JumpIfFalse), U8(32),
   /* 1518 E> */ B(StackCheck),
   /* 1555 S> */ B(Wide), B(Ldar), R16(128),
   /* 1561 E> */ B(Add), R(1),
                 B(Wide), B(Mov), R16(1), R16(157),
                 B(Star), R(1),
   /* 1548 S> */ B(Wide), B(Ldar), R16(128),
-                B(ToNumber),
-                B(Wide), B(Star), R16(157),
+                B(Wide), B(ToNumber), R16(157),
                 B(Inc),
                 B(Wide), B(Star), R16(128),
-                B(Jump), U8(-37),
+                B(Jump), U8(-36),
   /* 1567 S> */ B(Wide), B(Ldar), R16(128),
   /* 1580 S> */ B(Return),
 ]

test/unittests/interpreter/bytecode-array-builder-unittest.cc

@@ -180,7 +180,7 @@ TEST_F(BytecodeArrayBuilderTest, AllBytecodesGenerated) {
       .CompareOperation(Token::Value::IN, reg);
 
   // Emit cast operator invocations.
-  builder.CastAccumulatorToNumber()
+  builder.CastAccumulatorToNumber(reg)
       .CastAccumulatorToJSObject()
       .CastAccumulatorToName();