Add support for WritableRegister policy in the register allocator.

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
diff --git a/runtime/vm/intermediate_language_ia32.cc b/runtime/vm/intermediate_language_ia32.cc
index d27b20aea1921945bcd55f1d302755eaf05ed376..c06c98dce1dd51d4836c88bbb5048675e8ff9e00 100644
--- a/runtime/vm/intermediate_language_ia32.cc
+++ b/runtime/vm/intermediate_language_ia32.cc
@@ -920,7 +920,8 @@ LocationSummary* StoreIndexedInstr::MakeLocationSummary() const {
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   locs->set_in(0, Location::RequiresRegister());
   locs->set_in(1, Location::RequiresRegister());
-  locs->set_in(2, Location::RequiresRegister());
+  locs->set_in(2, value()->NeedsStoreBuffer() ? Location::WritableRegister()
+                                              : Location::RequiresRegister());
   if (receiver_type() == kGrowableObjectArrayCid) {
     locs->set_temp(0, Location::RequiresRegister());
   }
@@ -939,7 +940,8 @@ void StoreIndexedInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
       // Note that index is Smi, i.e, times 2.
       ASSERT(kSmiTagShift == 1);
       if (this->value()->NeedsStoreBuffer()) {
-        __ StoreIntoObject(receiver,
+        __ StoreIntoObject(

[Ivan Posva, 2012/09/11 11:57:30]

?

[Vyacheslav Egorov (Google), 2012/09/11 12:18:05]

Done.

+            receiver,
             FieldAddress(receiver, index, TIMES_2, sizeof(RawArray)),
             value);
       } else {
@@ -955,7 +957,8 @@ void StoreIndexedInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
       // Note that index is Smi, i.e, times 2.
       ASSERT(kSmiTagShift == 1);
       if (this->value()->NeedsStoreBuffer()) {
-        __ StoreIntoObject(temp,
+        __ StoreIntoObject(

[Ivan Posva, 2012/09/11 11:57:30]

?

[Vyacheslav Egorov (Google), 2012/09/11 12:18:05]

Done.

+            temp,
             FieldAddress(temp, index, TIMES_2, sizeof(RawArray)),
             value);
       } else {
@@ -997,7 +1000,9 @@ LocationSummary* StoreInstanceFieldInstr::MakeLocationSummary() const {
   LocationSummary* summary =
       new LocationSummary(kNumInputs, num_temps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresRegister());
-  summary->set_in(1, Location::RequiresRegister());
+  summary->set_in(1,
+      value()->NeedsStoreBuffer() ? Location::WritableRegister()
+                                  : Location::RequiresRegister());
   return summary;
 }
 
@@ -1006,8 +1011,10 @@ void StoreInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register instance_reg = locs()->in(0).reg();
   Register value_reg = locs()->in(1).reg();
   if (this->value()->NeedsStoreBuffer()) {
-    __ StoreIntoObject(instance_reg,
-        FieldAddress(instance_reg, field().Offset()), value_reg);
+    __ StoreIntoObject(
+        instance_reg,
+        FieldAddress(instance_reg, field().Offset()),
+        value_reg);
   } else {
     __ StoreIntoObjectNoBarrier(instance_reg,
         FieldAddress(instance_reg, field().Offset()), value_reg);
@@ -1031,10 +1038,9 @@ void LoadStaticFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 
 LocationSummary* StoreStaticFieldInstr::MakeLocationSummary() const {
   LocationSummary* locs = new LocationSummary(1, 1, LocationSummary::kNoCall);
-  locs->set_in(0, Location::RequiresRegister());
+  locs->set_in(0, value()->NeedsStoreBuffer() ? Location::WritableRegister()
+                                              : Location::RequiresRegister());
   locs->set_temp(0, Location::RequiresRegister());
-  locs->set_out(is_used() ? Location::SameAsFirstInput()
-                          : Location::NoLocation());
   return locs;
 }
 
@@ -1042,11 +1048,12 @@ LocationSummary* StoreStaticFieldInstr::MakeLocationSummary() const {
 void StoreStaticFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register value = locs()->in(0).reg();
   Register temp = locs()->temp(0).reg();
-  ASSERT(!is_used() || (locs()->out().reg() == value));
 
   __ LoadObject(temp, field());
   if (this->value()->NeedsStoreBuffer()) {
-    __ StoreIntoObject(temp, FieldAddress(temp, Field::value_offset()), value);
+    __ StoreIntoObject(temp,

[Ivan Posva, 2012/09/11 11:57:30]

ditto

[Vyacheslav Egorov (Google), 2012/09/11 12:18:05]

Done.

+                       FieldAddress(temp, Field::value_offset()),
+                       value);
   } else {
     __ StoreIntoObjectNoBarrier(
         temp, FieldAddress(temp, Field::value_offset()), value);