Add Crankshaft support for smi-only elements

Review URL: http://codereview.chromium.org/8002019

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9426 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-codegen-arm.cc

@@ -3346,6 +3346,13 @@ void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
   Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
   Register scratch = scratch0();
 
+  // This instruction cannot handle the FAST_SMI_ONLY_ELEMENTS -> FAST_ELEMENTS
+  // conversion, so it deopts in that case.
+  if (instr->hydrogen()->ValueNeedsSmiCheck()) {
+    __ tst(value, Operand(kSmiTagMask));
+    DeoptimizeIf(ne, instr->environment());
+  }
+
   // Do the store.
   if (instr->key()->IsConstantOperand()) {
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());

src/hydrogen-instructions.h

@@ -3740,7 +3740,9 @@ class HStoreNamedGeneric: public HTemplateInstruction<3> {
 
 class HStoreKeyedFastElement: public HTemplateInstruction<3> {
  public:
-  HStoreKeyedFastElement(HValue* obj, HValue* key, HValue* val) {
+  HStoreKeyedFastElement(HValue* obj, HValue* key, HValue* val,
+                         ElementsKind elements_kind = FAST_ELEMENTS)
+      : elements_kind_(elements_kind) {
     SetOperandAt(0, obj);
     SetOperandAt(1, key);
     SetOperandAt(2, val);
@@ -3757,14 +3759,28 @@ class HStoreKeyedFastElement: public HTemplateInstruction<3> {
   HValue* object() { return OperandAt(0); }
   HValue* key() { return OperandAt(1); }
   HValue* value() { return OperandAt(2); }
+  bool value_is_smi() {
+    return elements_kind_ == FAST_SMI_ONLY_ELEMENTS;
+  }
 
   bool NeedsWriteBarrier() {
+    if (value_is_smi()) {
+      return false;
+    } else {
       return StoringValueNeedsWriteBarrier(value());
     }
+  }
+
+  bool ValueNeedsSmiCheck() {
+    return value_is_smi();
+  }
 
   virtual void PrintDataTo(StringStream* stream);
 
   DECLARE_CONCRETE_INSTRUCTION(StoreKeyedFastElement)
+
+ private:
+  ElementsKind elements_kind_;
 };
 
 

src/hydrogen.h

@@ -942,6 +942,11 @@ class HGraphBuilder: public AstVisitor {
       HValue* val,
       ElementsKind elements_kind,
       bool is_store);
+  HInstruction* BuildFastElementAccess(HValue* elements,
+                                       HValue* checked_key,
+                                       HValue* val,
+                                       ElementsKind elements_kind,
+                                       bool is_store);
 
   HInstruction* BuildMonomorphicElementAccess(HValue* object,
                                               HValue* key,

src/ia32/lithium-codegen-ia32.cc

@@ -3238,6 +3238,13 @@ void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
   Register elements = ToRegister(instr->object());
   Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
 
+  // This instruction cannot handle the FAST_SMI_ONLY_ELEMENTS -> FAST_ELEMENTS
+  // conversion, so it deopts in that case.
+  if (instr->hydrogen()->ValueNeedsSmiCheck()) {
+    __ test(value, Immediate(kSmiTagMask));
+    DeoptimizeIf(not_zero, instr->environment());
+  }
+
   // Do the store.
   if (instr->key()->IsConstantOperand()) {
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());

src/ic.cc

@@ -1689,6 +1689,7 @@ MaybeObject* KeyedIC::ComputeMonomorphicStub(JSObject* receiver,
                                              Code* generic_stub) {
   Code* result = NULL;
   if (receiver->HasFastElements() ||
+      receiver->HasFastSmiOnlyElements() ||
       receiver->HasExternalArrayElements() ||
       receiver->HasFastDoubleElements() ||
       receiver->HasDictionaryElements()) {

src/runtime.cc

@@ -443,7 +443,7 @@ static Handle<Object> CreateArrayLiteralBoilerplate(
       for (int i = 0; i < content->length(); i++) {
         Object* current = content->get(i);
         ASSERT(!current->IsFixedArray());
-        if (!current->IsSmi()) {
+        if (!current->IsSmi() && !current->IsTheHole()) {
           has_non_smi = true;
         }
       }
@@ -467,7 +467,7 @@ static Handle<Object> CreateArrayLiteralBoilerplate(
         content->set(i, *result);
         has_non_smi = true;
       } else {
-        if (!current->IsSmi()) {
+        if (!current->IsSmi() && !current->IsTheHole()) {
           has_non_smi = true;
         }
       }
@@ -8250,6 +8250,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_OptimizeFunctionOnNextCall) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetOptimizationStatus) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
+  // The least significant bit (after untagging) indicates whether the
+  // function is currently optimized, regardless of reason.
   if (!V8::UseCrankshaft()) {
     return Smi::FromInt(4);  // 4 == "never".
   }

src/x64/lithium-codegen-x64.cc

@@ -3161,6 +3161,13 @@ void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
   Register elements = ToRegister(instr->object());
   Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
 
+  // This instruction cannot handle the FAST_SMI_ONLY_ELEMENTS -> FAST_ELEMENTS
+  // conversion, so it deopts in that case.
+  if (instr->hydrogen()->ValueNeedsSmiCheck()) {
+    Condition cc = masm()->CheckSmi(value);
+    DeoptimizeIf(NegateCondition(cc), instr->environment());
+  }
+
   // Do the store.
   if (instr->key()->IsConstantOperand()) {
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());

test/mjsunit/element-kind.js

@@ -125,3 +125,70 @@ assertKind(element_kind.external_unsigned_int_elements,   new Uint32Array(23));
 assertKind(element_kind.external_float_elements,          new Float32Array(7));
 assertKind(element_kind.external_double_elements,         new Float64Array(0));
 assertKind(element_kind.external_pixel_elements,          new PixelArray(512));
+
+// Crankshaft support for smi-only array elements.
+function monomorphic(array) {
+  for (var i = 0; i < 3; i++) {
+    array[i] = i + 10;
+  }
+  assertKind(element_kind.fast_smi_only_elements, array);
+  for (var i = 0; i < 3; i++) {
+    var a = array[i];
+    assertEquals(i + 10, a);
+  }
+}
+var smi_only = [1, 2, 3];
+for (var i = 0; i < 3; i++) monomorphic(smi_only);
+%OptimizeFunctionOnNextCall(monomorphic);
+monomorphic(smi_only);
+function polymorphic(array, expected_kind) {
+  array[1] = 42;
+  assertKind(expected_kind, array);
+  var a = array[1];
+  assertEquals(42, a);
+}
+var smis = [1, 2, 3];
+var strings = ["one", "two", "three"];
+var doubles = [0, 0, 0]; doubles[0] = 1.5; doubles[1] = 2.5; doubles[2] = 3.5;
+assertKind(support_smi_only_arrays
+               ? element_kind.fast_double_elements
+               : element_kind.fast_elements,
+           doubles);
+for (var i = 0; i < 3; i++) {
+  polymorphic(smis, element_kind.fast_smi_only_elements);
+  polymorphic(strings, element_kind.fast_elements);
+  polymorphic(doubles, support_smi_only_arrays
+                           ? element_kind.fast_double_elements
+                           : element_kind.fast_elements);
+}
+%OptimizeFunctionOnNextCall(polymorphic);
+polymorphic(smis, element_kind.fast_smi_only_elements);
+polymorphic(strings, element_kind.fast_elements);
+polymorphic(doubles, support_smi_only_arrays
+    ? element_kind.fast_double_elements
+    : element_kind.fast_elements);
+
+// Crankshaft support for smi-only elements in dynamic array literals.
+function get(foo) { return foo; }  // Used to generate dynamic values.
+
+//function crankshaft_test(expected_kind) {
+function crankshaft_test() {
+  var a = [get(1), get(2), get(3)];
+  assertKind(element_kind.fast_smi_only_elements, a);
+  var b = [get(1), get(2), get("three")];
+  assertKind(element_kind.fast_elements, b);
+  var c = [get(1), get(2), get(3.5)];
+  // The full code generator doesn't support conversion to fast_double_elements
+  // yet. Crankshaft does, but only with --smi-only-arrays support.
+  if ((%GetOptimizationStatus(crankshaft_test) & 1) &&
+      support_smi_only_arrays) {
+    assertKind(element_kind.fast_double_elements, c);
+  } else {
+    assertKind(element_kind.fast_elements, c);
+  }
+}
+for (var i = 0; i < 3; i++) {
+  crankshaft_test();
+}
+%OptimizeFunctionOnNextCall(crankshaft_test);
+crankshaft_test();