ARM: Let the register allocator handle the context register.

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index 6fdbbb58934c0e852df086b589f55edab6f85905..efed5f282b7f3e875e1fd952d179b340ca78c635 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -779,10 +779,11 @@ LInstruction* LChunkBuilder::DoArithmeticT(Token::Value op,
   HValue* right = instr->right();
   ASSERT(left->representation().IsTagged());
   ASSERT(right->representation().IsTagged());
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* left_operand = UseFixed(left, r1);
   LOperand* right_operand = UseFixed(right, r0);
   LArithmeticT* result =
-      new(zone()) LArithmeticT(op, left_operand, right_operand);
+      new(zone()) LArithmeticT(op, context, left_operand, right_operand);
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
@@ -1044,9 +1045,10 @@ LInstruction* LChunkBuilder::DoArgumentsElements(HArgumentsElements* elems) {
 
 
 LInstruction* LChunkBuilder::DoInstanceOf(HInstanceOf* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LInstanceOf* result =
-      new(zone()) LInstanceOf(UseFixed(instr->left(), r0),
-                      UseFixed(instr->right(), r1));
+      new(zone()) LInstanceOf(context, UseFixed(instr->left(), r0),
+                              UseFixed(instr->right(), r1));
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
@@ -1054,8 +1056,10 @@ LInstruction* LChunkBuilder::DoInstanceOf(HInstanceOf* instr) {
 LInstruction* LChunkBuilder::DoInstanceOfKnownGlobal(
     HInstanceOfKnownGlobal* instr) {
   LInstanceOfKnownGlobal* result =
-      new(zone()) LInstanceOfKnownGlobal(UseFixed(instr->left(), r0),
-                                         FixedTemp(r4));
+      new(zone()) LInstanceOfKnownGlobal(
+          UseFixed(instr->context(), cp),
+          UseFixed(instr->left(), r0),
+          FixedTemp(r4));
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
@@ -1119,14 +1123,13 @@ LInstruction* LChunkBuilder::DoThisFunction(HThisFunction* instr) {
 
 
 LInstruction* LChunkBuilder::DoContext(HContext* instr) {
-  // If there is a non-return use, the context must be allocated in a register.
-  for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
-    if (!it.value()->IsReturn()) {
-      return DefineAsRegister(new(zone()) LContext);
-    }
+  if (instr->HasNoUses()) return NULL;
+
+  if (info()->IsStub()) {
+    return DefineFixed(new(zone()) LContext, cp);
   }
 
-  return NULL;
+  return DefineAsRegister(new(zone()) LContext);
 }
 
 
@@ -1137,7 +1140,8 @@ LInstruction* LChunkBuilder::DoOuterContext(HOuterContext* instr) {
 
 
 LInstruction* LChunkBuilder::DoDeclareGlobals(HDeclareGlobals* instr) {
-  return MarkAsCall(new(zone()) LDeclareGlobals, instr);
+  LOperand* context = UseFixed(instr->context(), cp);
+  return MarkAsCall(new(zone()) LDeclareGlobals(context), instr);
 }
 
 
@@ -1161,9 +1165,10 @@ LInstruction* LChunkBuilder::DoCallConstantFunction(
 
 
 LInstruction* LChunkBuilder::DoInvokeFunction(HInvokeFunction* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* function = UseFixed(instr->function(), r1);
   argument_count_ -= instr->argument_count();
-  LInvokeFunction* result = new(zone()) LInvokeFunction(function);
+  LInvokeFunction* result = new(zone()) LInvokeFunction(context, function);
   return MarkAsCall(DefineFixed(result, r0), instr, CANNOT_DEOPTIMIZE_EAGERLY);
 }
 
@@ -1203,8 +1208,12 @@ LInstruction* LChunkBuilder::DoMathRound(HUnaryMathOperation* instr) {
 
 
 LInstruction* LChunkBuilder::DoMathAbs(HUnaryMathOperation* instr) {
+  Representation r = instr->value()->representation();
+  LOperand* context = (r.IsDouble() || r.IsSmiOrInteger32())
+      ? NULL
+      : UseFixed(instr->context(), cp);

[ulan, 2013/09/27 12:08:00]

I think we can use UseAny here because the context is used in deferred code.

[vincent.belliard.fr, 2013/09/27 12:37:04]

If we use UseAny, the context will we copied into cp if necessary. However, as
at the end we need the context in cp, I think it's better to let the allocator
moving the context into cp (in some case, it should avoid some mov).

In fact, it's just a question of probability, we should use the deferred code
most of the time because it's not used only when we have a tagged value which is
a smi (untagged cases don't need the context). I think that there are more
probabilities that a tagged value hold a number or an integer than a smi because
the cases untagged number, untagged integer or smi are already managed by a
different path.

If you think these assertions are false, I will put UseAny.

[ulan, 2013/09/27 12:44:13]

OK, let's leave UseFixed.

   LOperand* input = UseRegister(instr->value());
-  LMathAbs* result = new(zone()) LMathAbs(input);
+  LMathAbs* result = new(zone()) LMathAbs(context, input);
   return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
 }
 
@@ -1266,21 +1275,25 @@ LInstruction* LChunkBuilder::DoMathPowHalf(HUnaryMathOperation* instr) {
 
 LInstruction* LChunkBuilder::DoCallKeyed(HCallKeyed* instr) {
   ASSERT(instr->key()->representation().IsTagged());
+  LOperand* context = UseFixed(instr->context(), cp);
   argument_count_ -= instr->argument_count();
   LOperand* key = UseFixed(instr->key(), r2);
-  return MarkAsCall(DefineFixed(new(zone()) LCallKeyed(key), r0), instr);
+  return MarkAsCall(
+        DefineFixed(new(zone()) LCallKeyed(context, key), r0), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoCallNamed(HCallNamed* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   argument_count_ -= instr->argument_count();
-  return MarkAsCall(DefineFixed(new(zone()) LCallNamed, r0), instr);
+  return MarkAsCall(DefineFixed(new(zone()) LCallNamed(context), r0), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoCallGlobal(HCallGlobal* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   argument_count_ -= instr->argument_count();
-  return MarkAsCall(DefineFixed(new(zone()) LCallGlobal, r0), instr);
+  return MarkAsCall(DefineFixed(new(zone()) LCallGlobal(context), r0), instr);
 }
 
 
@@ -1291,32 +1304,36 @@ LInstruction* LChunkBuilder::DoCallKnownGlobal(HCallKnownGlobal* instr) {
 
 
 LInstruction* LChunkBuilder::DoCallNew(HCallNew* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* constructor = UseFixed(instr->constructor(), r1);
   argument_count_ -= instr->argument_count();
-  LCallNew* result = new(zone()) LCallNew(constructor);
+  LCallNew* result = new(zone()) LCallNew(context, constructor);
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoCallNewArray(HCallNewArray* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* constructor = UseFixed(instr->constructor(), r1);
   argument_count_ -= instr->argument_count();
-  LCallNewArray* result = new(zone()) LCallNewArray(constructor);
+  LCallNewArray* result = new(zone()) LCallNewArray(context, constructor);
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoCallFunction(HCallFunction* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* function = UseFixed(instr->function(), r1);
   argument_count_ -= instr->argument_count();
-  return MarkAsCall(DefineFixed(new(zone()) LCallFunction(function), r0),
-                    instr);
+  return MarkAsCall(
+      DefineFixed(new(zone()) LCallFunction(context, function), r0), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoCallRuntime(HCallRuntime* instr) {
   argument_count_ -= instr->argument_count();
-  return MarkAsCall(DefineFixed(new(zone()) LCallRuntime, r0), instr);
+  LOperand* context = UseFixed(instr->context(), cp);
+  return MarkAsCall(DefineFixed(new(zone()) LCallRuntime(context), r0), instr);
 }
 
 
@@ -1719,9 +1736,10 @@ LInstruction* LChunkBuilder::DoRandom(HRandom* instr) {
 LInstruction* LChunkBuilder::DoCompareGeneric(HCompareGeneric* instr) {
   ASSERT(instr->left()->representation().IsTagged());
   ASSERT(instr->right()->representation().IsTagged());
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* left = UseFixed(instr->left(), r1);
   LOperand* right = UseFixed(instr->right(), r0);
-  LCmpT* result = new(zone()) LCmpT(left, right);
+  LCmpT* result = new(zone()) LCmpT(context, left, right);
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
@@ -1795,10 +1813,11 @@ LInstruction* LChunkBuilder::DoStringCompareAndBranch(
     HStringCompareAndBranch* instr) {
   ASSERT(instr->left()->representation().IsTagged());
   ASSERT(instr->right()->representation().IsTagged());
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* left = UseFixed(instr->left(), r1);
   LOperand* right = UseFixed(instr->right(), r0);
   LStringCompareAndBranch* result =
-      new(zone()) LStringCompareAndBranch(left, right);
+      new(zone()) LStringCompareAndBranch(context, left, right);
   return MarkAsCall(result, instr);
 }
 
@@ -1886,8 +1905,9 @@ LInstruction* LChunkBuilder::DoBoundsCheckBaseIndexInformation(
 
 
 LInstruction* LChunkBuilder::DoThrow(HThrow* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* value = UseFixed(instr->value(), r0);
-  return MarkAsCall(new(zone()) LThrow(value), instr);
+  return MarkAsCall(new(zone()) LThrow(context, value), instr);
 }
 
 
@@ -2067,8 +2087,11 @@ LInstruction* LChunkBuilder::DoClampToUint8(HClampToUint8* instr) {
 
 
 LInstruction* LChunkBuilder::DoReturn(HReturn* instr) {
+  LOperand* context = info()->IsStub()
+      ? UseFixed(instr->context(), cp)
+      : NULL;
   LOperand* parameter_count = UseRegisterOrConstant(instr->parameter_count());
-  return new(zone()) LReturn(UseFixed(instr->value(), r0),
+  return new(zone()) LReturn(UseFixed(instr->value(), r0), context,
                              parameter_count);
 }
 
@@ -2101,8 +2124,10 @@ LInstruction* LChunkBuilder::DoLoadGlobalCell(HLoadGlobalCell* instr) {
 
 
 LInstruction* LChunkBuilder::DoLoadGlobalGeneric(HLoadGlobalGeneric* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* global_object = UseFixed(instr->global_object(), r0);
-  LLoadGlobalGeneric* result = new(zone()) LLoadGlobalGeneric(global_object);
+  LLoadGlobalGeneric* result =
+      new(zone()) LLoadGlobalGeneric(context, global_object);
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
@@ -2118,10 +2143,11 @@ LInstruction* LChunkBuilder::DoStoreGlobalCell(HStoreGlobalCell* instr) {
 
 
 LInstruction* LChunkBuilder::DoStoreGlobalGeneric(HStoreGlobalGeneric* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* global_object = UseFixed(instr->global_object(), r1);
   LOperand* value = UseFixed(instr->value(), r0);
   LStoreGlobalGeneric* result =
-      new(zone()) LStoreGlobalGeneric(global_object, value);
+      new(zone()) LStoreGlobalGeneric(context, global_object, value);
   return MarkAsCall(result, instr);
 }
 
@@ -2156,8 +2182,10 @@ LInstruction* LChunkBuilder::DoLoadNamedField(HLoadNamedField* instr) {
 
 
 LInstruction* LChunkBuilder::DoLoadNamedGeneric(HLoadNamedGeneric* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* object = UseFixed(instr->object(), r0);
-  LInstruction* result = DefineFixed(new(zone()) LLoadNamedGeneric(object), r0);
+  LInstruction* result =
+      DefineFixed(new(zone()) LLoadNamedGeneric(context, object), r0);
   return MarkAsCall(result, instr);
 }
 
@@ -2218,11 +2246,12 @@ LInstruction* LChunkBuilder::DoLoadKeyed(HLoadKeyed* instr) {
 
 
 LInstruction* LChunkBuilder::DoLoadKeyedGeneric(HLoadKeyedGeneric* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* object = UseFixed(instr->object(), r1);
   LOperand* key = UseFixed(instr->key(), r0);
 
   LInstruction* result =
-      DefineFixed(new(zone()) LLoadKeyedGeneric(object, key), r0);
+      DefineFixed(new(zone()) LLoadKeyedGeneric(context, object, key), r0);
   return MarkAsCall(result, instr);
 }
 
@@ -2271,6 +2300,7 @@ LInstruction* LChunkBuilder::DoStoreKeyed(HStoreKeyed* instr) {
 
 
 LInstruction* LChunkBuilder::DoStoreKeyedGeneric(HStoreKeyedGeneric* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* obj = UseFixed(instr->object(), r2);
   LOperand* key = UseFixed(instr->key(), r1);
   LOperand* val = UseFixed(instr->value(), r0);
@@ -2279,7 +2309,8 @@ LInstruction* LChunkBuilder::DoStoreKeyedGeneric(HStoreKeyedGeneric* instr) {
   ASSERT(instr->key()->representation().IsTagged());
   ASSERT(instr->value()->representation().IsTagged());
 
-  return MarkAsCall(new(zone()) LStoreKeyedGeneric(obj, key, val), instr);
+  return MarkAsCall(
+      new(zone()) LStoreKeyedGeneric(context, obj, key, val), instr);
 }
 
 
@@ -2289,11 +2320,12 @@ LInstruction* LChunkBuilder::DoTransitionElementsKind(
   if (IsSimpleMapChangeTransition(instr->from_kind(), instr->to_kind())) {
     LOperand* new_map_reg = TempRegister();
     LTransitionElementsKind* result =
-        new(zone()) LTransitionElementsKind(object, new_map_reg);
+        new(zone()) LTransitionElementsKind(object, NULL, new_map_reg);
     return result;
   } else {
+    LOperand* context = UseFixed(instr->context(), cp);
     LTransitionElementsKind* result =
-        new(zone()) LTransitionElementsKind(object, NULL);
+        new(zone()) LTransitionElementsKind(object, context, NULL);
     return AssignPointerMap(result);
   }
 }
@@ -2352,56 +2384,68 @@ LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
 
 
 LInstruction* LChunkBuilder::DoStoreNamedGeneric(HStoreNamedGeneric* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* obj = UseFixed(instr->object(), r1);
   LOperand* val = UseFixed(instr->value(), r0);
 
-  LInstruction* result = new(zone()) LStoreNamedGeneric(obj, val);
+  LInstruction* result = new(zone()) LStoreNamedGeneric(context, obj, val);
   return MarkAsCall(result, instr);
 }
 
 
 LInstruction* LChunkBuilder::DoStringAdd(HStringAdd* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* left = UseRegisterAtStart(instr->left());
   LOperand* right = UseRegisterAtStart(instr->right());
-  return MarkAsCall(DefineFixed(new(zone()) LStringAdd(left, right), r0),
-                    instr);
+  return MarkAsCall(
+      DefineFixed(new(zone()) LStringAdd(context, left, right), r0),
+      instr);
 }
 
 
 LInstruction* LChunkBuilder::DoStringCharCodeAt(HStringCharCodeAt* instr) {
   LOperand* string = UseTempRegister(instr->string());
   LOperand* index = UseTempRegister(instr->index());
-  LStringCharCodeAt* result = new(zone()) LStringCharCodeAt(string, index);
+  LOperand* context = UseAny(instr->context());
+  LStringCharCodeAt* result =
+      new(zone()) LStringCharCodeAt(context, string, index);
   return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
 }
 
 
 LInstruction* LChunkBuilder::DoStringCharFromCode(HStringCharFromCode* instr) {
   LOperand* char_code = UseRegister(instr->value());
-  LStringCharFromCode* result = new(zone()) LStringCharFromCode(char_code);
+  LOperand* context = UseAny(instr->context());
+  LStringCharFromCode* result =
+      new(zone()) LStringCharFromCode(context, char_code);
   return AssignPointerMap(DefineAsRegister(result));
 }
 
 
 LInstruction* LChunkBuilder::DoAllocate(HAllocate* instr) {
   info()->MarkAsDeferredCalling();
+  LOperand* context = UseAny(instr->context());
   LOperand* size = instr->size()->IsConstant()
       ? UseConstant(instr->size())
       : UseTempRegister(instr->size());
   LOperand* temp1 = TempRegister();
   LOperand* temp2 = TempRegister();
-  LAllocate* result = new(zone()) LAllocate(size, temp1, temp2);
+  LAllocate* result = new(zone()) LAllocate(context, size, temp1, temp2);
   return AssignPointerMap(DefineAsRegister(result));
 }
 
 
 LInstruction* LChunkBuilder::DoRegExpLiteral(HRegExpLiteral* instr) {
-  return MarkAsCall(DefineFixed(new(zone()) LRegExpLiteral, r0), instr);
+  LOperand* context = UseFixed(instr->context(), cp);
+  return MarkAsCall(
+      DefineFixed(new(zone()) LRegExpLiteral(context), r0), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoFunctionLiteral(HFunctionLiteral* instr) {
-  return MarkAsCall(DefineFixed(new(zone()) LFunctionLiteral, r0), instr);
+  LOperand* context = UseFixed(instr->context(), cp);
+  return MarkAsCall(
+      DefineFixed(new(zone()) LFunctionLiteral(context), r0), instr);
 }
 
 
@@ -2448,8 +2492,9 @@ LInstruction* LChunkBuilder::DoUnknownOSRValue(HUnknownOSRValue* instr) {
 
 
 LInstruction* LChunkBuilder::DoCallStub(HCallStub* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   argument_count_ -= instr->argument_count();
-  return MarkAsCall(DefineFixed(new(zone()) LCallStub, r0), instr);
+  return MarkAsCall(DefineFixed(new(zone()) LCallStub(context), r0), instr);
 }
 
 
@@ -2494,7 +2539,8 @@ LInstruction* LChunkBuilder::DoToFastProperties(HToFastProperties* instr) {
 
 
 LInstruction* LChunkBuilder::DoTypeof(HTypeof* instr) {
-  LTypeof* result = new(zone()) LTypeof(UseFixed(instr->value(), r0));
+  LOperand* context = UseFixed(instr->context(), cp);
+  LTypeof* result = new(zone()) LTypeof(context, UseFixed(instr->value(), r0));
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
@@ -2533,10 +2579,13 @@ LInstruction* LChunkBuilder::DoSimulate(HSimulate* instr) {
 
 LInstruction* LChunkBuilder::DoStackCheck(HStackCheck* instr) {
   if (instr->is_function_entry()) {
-    return MarkAsCall(new(zone()) LStackCheck, instr);
+    LOperand* context = UseFixed(instr->context(), cp);
+    return MarkAsCall(new(zone()) LStackCheck(context), instr);
   } else {
     ASSERT(instr->is_backwards_branch());
-    return AssignEnvironment(AssignPointerMap(new(zone()) LStackCheck));
+    LOperand* context = UseAny(instr->context());
+    return AssignEnvironment(
+        AssignPointerMap(new(zone()) LStackCheck(context)));
   }
 }
 
@@ -2581,8 +2630,9 @@ LInstruction* LChunkBuilder::DoLeaveInlined(HLeaveInlined* instr) {
 
 
 LInstruction* LChunkBuilder::DoForInPrepareMap(HForInPrepareMap* instr) {
+  LOperand* context = UseFixed(instr->context(), cp);
   LOperand* object = UseFixed(instr->enumerable(), r0);
-  LForInPrepareMap* result = new(zone()) LForInPrepareMap(object);
+  LForInPrepareMap* result = new(zone()) LForInPrepareMap(context, object);
   return MarkAsCall(DefineFixed(result, r0), instr, CAN_DEOPTIMIZE_EAGERLY);
 }