Use type propagation to eliminate store barriers.

Review URL: https://chromiumcodereview.appspot.com//10876072

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@11357 260f80e4-7a28-3924-810f-c04153c831b5

runtime/vm/intermediate_language.cc

@@ -292,6 +292,15 @@ bool Value::CompileTypeIsMoreSpecificThan(const AbstractType& dst_type) const {
 }
 
 
+bool Value::NeedsStoreBuffer() const {
+  const intptr_t cid = ResultCid();
+  if ((cid == kSmiCid) || (cid == kBoolCid) || (cid == kNullCid)) {
+    return false;
+  }
+  return !BindsToConstant();
+}
+
+
 RawAbstractType* PhiInstr::CompileType() const {
   ASSERT(!HasPropagatedType());
   // Since type propagation has not yet occured, we are reaching this phi via a
@@ -1432,8 +1441,13 @@ void StoreVMFieldComp::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register dest_reg = locs()->in(1).reg();
   ASSERT(value_reg == locs()->out().reg());
 
-  __ StoreIntoObject(dest_reg, FieldAddress(dest_reg, offset_in_bytes()),
+  if (value()->NeedsStoreBuffer()) {
-                     value_reg);
+    __ StoreIntoObject(dest_reg, FieldAddress(dest_reg, offset_in_bytes()),
+                       value_reg);
+  } else {
+    __ StoreIntoObjectNoBarrier(
+        dest_reg, FieldAddress(dest_reg, offset_in_bytes()), value_reg);
+  }
 }
 
 

runtime/vm/intermediate_language.h

@@ -361,6 +361,10 @@ FOR_EACH_VALUE(DECLARE_PREDICATE)
   // specific than any type.
   bool CompileTypeIsMoreSpecificThan(const AbstractType& dst_type) const;
 
+  // Compile time constants, Bool, Smi and Nulls do not need to update
+  // the store buffer.
+  bool NeedsStoreBuffer() const;
+
   virtual bool Equals(Value* other) const = 0;
 
   virtual Value* CopyValue() = 0;

runtime/vm/intermediate_language_ia32.cc

@@ -901,12 +901,12 @@ void StoreIndexedComp::EmitNativeCode(FlowGraphCompiler* compiler) {
       __ j(ABOVE_EQUAL, deopt);
       // Note that index is Smi, i.e, times 2.
       ASSERT(kSmiTagShift == 1);
-      if (this->value()->BindsToConstant()) {
+      if (this->value()->NeedsStoreBuffer()) {
-        // Compile time constants are Smi or allocated in the old space.
+        __ StoreIntoObject(receiver,
-        __ movl(FieldAddress(receiver, index, TIMES_2, sizeof(RawArray)),
+            FieldAddress(receiver, index, TIMES_2, sizeof(RawArray)),
             value);
       } else {
-        __ StoreIntoObject(receiver,
+        __ StoreIntoObjectNoBarrier(receiver,
             FieldAddress(receiver, index, TIMES_2, sizeof(RawArray)),
             value);
       }
@@ -919,12 +919,12 @@ void StoreIndexedComp::EmitNativeCode(FlowGraphCompiler* compiler) {
       __ movl(temp, FieldAddress(receiver, GrowableObjectArray::data_offset()));
       // Note that index is Smi, i.e, times 2.
       ASSERT(kSmiTagShift == 1);
-      if (this->value()->BindsToConstant()) {
+      if (this->value()->NeedsStoreBuffer()) {
-        // Compile time constants are Smi or allocated in the old space.
+        __ StoreIntoObject(temp,
-        __ movl(FieldAddress(temp, index, TIMES_2, sizeof(RawArray)),
+            FieldAddress(temp, index, TIMES_2, sizeof(RawArray)),
             value);
       } else {
-        __ StoreIntoObject(temp,
+        __ StoreIntoObjectNoBarrier(temp,
             FieldAddress(temp, index, TIMES_2, sizeof(RawArray)),
             value);
       }
@@ -998,12 +998,12 @@ void StoreInstanceFieldComp::EmitNativeCode(FlowGraphCompiler* compiler) {
     ASSERT(ic_data() != NULL);
     compiler->EmitClassChecksNoSmi(*ic_data(), instance_reg, temp_reg, deopt);
   }
-  if (this->value()->BindsToConstant()) {
+  if (this->value()->NeedsStoreBuffer()) {
-    // Compile time constants are Smi or allocated in the old space.
-    __ movl(FieldAddress(instance_reg, field().Offset()), value_reg);
-  } else {
     __ StoreIntoObject(instance_reg,
         FieldAddress(instance_reg, field().Offset()), value_reg);
+  } else {
+    __ StoreIntoObjectNoBarrier(instance_reg,
+        FieldAddress(instance_reg, field().Offset()), value_reg);
   }
 }
 
@@ -1037,11 +1037,11 @@ void StoreStaticFieldComp::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT(locs()->out().reg() == value);
 
   __ LoadObject(temp, field());
-  if (this->value()->BindsToConstant()) {
+  if (this->value()->NeedsStoreBuffer()) {
-    // Compile time constants are Smi or allocated in the old space.
-    __ movl(FieldAddress(temp, Field::value_offset()), value);
-  } else {
     __ StoreIntoObject(temp, FieldAddress(temp, Field::value_offset()), value);
+  } else {
+    __ StoreIntoObjectNoBarrier(
+        temp, FieldAddress(temp, Field::value_offset()), value);
   }
 }
 

runtime/vm/intermediate_language_x64.cc

@@ -920,12 +920,12 @@ void StoreIndexedComp::EmitNativeCode(FlowGraphCompiler* compiler) {
       __ j(ABOVE_EQUAL, deopt);
       // Note that index is Smi, i.e, times 4.
       ASSERT(kSmiTagShift == 1);
-      if (this->value()->BindsToConstant()) {
+      if (this->value()->NeedsStoreBuffer()) {
-        // Compile time constants are Smi or allocated in the old space.
+        __ StoreIntoObject(receiver,
-        __ movq(FieldAddress(receiver, index, TIMES_4, sizeof(RawArray)),
+            FieldAddress(receiver, index, TIMES_4, sizeof(RawArray)),
             value);
       } else {
-        __ StoreIntoObject(receiver,
+        __ StoreIntoObjectNoBarrier(receiver,
             FieldAddress(receiver, index, TIMES_4, sizeof(RawArray)),
             value);
       }
@@ -939,12 +939,12 @@ void StoreIndexedComp::EmitNativeCode(FlowGraphCompiler* compiler) {
       __ movq(temp, FieldAddress(receiver, GrowableObjectArray::data_offset()));
       // Note that index is Smi, i.e, times 4.
       ASSERT(kSmiTagShift == 1);
-      if (this->value()->BindsToConstant()) {
+      if (this->value()->NeedsStoreBuffer()) {
-        // Compile time constants are Smi or allocated in the old space.
+        __ StoreIntoObject(temp,
-        __ movq(FieldAddress(temp, index, TIMES_4, sizeof(RawArray)),
+            FieldAddress(temp, index, TIMES_4, sizeof(RawArray)),
             value);
       } else {
-        __ StoreIntoObject(temp,
+        __ StoreIntoObjectNoBarrier(temp,
             FieldAddress(temp, index, TIMES_4, sizeof(RawArray)),
             value);
       }
@@ -1018,12 +1018,12 @@ void StoreInstanceFieldComp::EmitNativeCode(FlowGraphCompiler* compiler) {
     ASSERT(ic_data() != NULL);
     compiler->EmitClassChecksNoSmi(*ic_data(), instance_reg, temp_reg, deopt);
   }
-  if (this->value()->BindsToConstant()) {
+  if (this->value()->NeedsStoreBuffer()) {
-    // Compile time constants are Smi or allocated in the old space.
-    __ movq(FieldAddress(instance_reg, field().Offset()), value_reg);
-  } else {
     __ StoreIntoObject(instance_reg,
         FieldAddress(instance_reg, field().Offset()), value_reg);
+  } else {
+    __ StoreIntoObjectNoBarrier(instance_reg,
+        FieldAddress(instance_reg, field().Offset()), value_reg);
   }
 }
 
@@ -1057,11 +1057,11 @@ void StoreStaticFieldComp::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT(locs()->out().reg() == value);
 
   __ LoadObject(temp, field());
-  if (this->value()->BindsToConstant()) {
+  if (this->value()->NeedsStoreBuffer()) {
-    // Compile time constants are Smi or allocated in the old space.
-    __ movq(FieldAddress(temp, Field::value_offset()), value);
-  } else {
     __ StoreIntoObject(temp, FieldAddress(temp, Field::value_offset()), value);
+  } else {
+    __ StoreIntoObjectNoBarrier(
+        temp, FieldAddress(temp, Field::value_offset()), value);
   }
 }