Support reusable boxes for Float32x4 fields

runtime/vm/intermediate_language_mips.cc

Index: runtime/vm/intermediate_language_mips.cc
diff --git a/runtime/vm/intermediate_language_mips.cc b/runtime/vm/intermediate_language_mips.cc
index 450c24bc6e595402959ea7c1ddae95ff89f0751b..007b44c11b4c1321f25937fd0df6fbcf13b690e9 100644
--- a/runtime/vm/intermediate_language_mips.cc
+++ b/runtime/vm/intermediate_language_mips.cc
@@ -1740,9 +1740,11 @@ void StoreInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
         default:
           UNREACHABLE();
       }
+
       StoreInstanceFieldSlowPath* slow_path =
           new StoreInstanceFieldSlowPath(this, *cls);
       compiler->AddSlowPathCode(slow_path);
+
       __ TryAllocate(*cls,
                      slow_path->entry_label(),
                      temp,
@@ -1772,7 +1774,6 @@ void StoreInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
     DRegister fpu_temp = locs()->temp(2).fpu_reg();
 
     Label store_pointer;
-    Label copy_double;
     Label store_double;
 
     __ LoadObject(temp, Field::ZoneHandle(field().raw()));
@@ -1790,37 +1791,42 @@ void StoreInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
     // Fall through.
     __ b(&store_pointer);
 
-    __ Bind(&store_double);
-
-    __ lw(temp, FieldAddress(instance_reg, field().Offset()));
-    __ BranchNotEqual(temp, reinterpret_cast<int32_t>(Object::null()),
-                      &copy_double);
-
-    StoreInstanceFieldSlowPath* slow_path =
-        new StoreInstanceFieldSlowPath(this, compiler->double_class());
-    compiler->AddSlowPathCode(slow_path);
-
     if (!compiler->is_optimizing()) {
       locs()->live_registers()->Add(locs()->in(0));
       locs()->live_registers()->Add(locs()->in(1));
     }
 
-    __ TryAllocate(compiler->double_class(),
-                   slow_path->entry_label(),
-                   temp,
-                   temp2);
-    __ Bind(slow_path->exit_label());
-    __ mov(temp2, temp);
-    __ StoreIntoObject(instance_reg,
-                       FieldAddress(instance_reg, field().Offset()),
-                       temp2);
+    {
+      __ Bind(&store_double);
+      Label copy_double;
+
+      __ lw(temp, FieldAddress(instance_reg, field().Offset()));
+      __ BranchNotEqual(temp, reinterpret_cast<int32_t>(Object::null()),
+                        &copy_double);
+
+      StoreInstanceFieldSlowPath* slow_path =
+          new StoreInstanceFieldSlowPath(this, compiler->double_class());
+      compiler->AddSlowPathCode(slow_path);
+
+      __ TryAllocate(compiler->double_class(),
+                     slow_path->entry_label(),
+                     temp,
+                     temp2);
+      __ Bind(slow_path->exit_label());
+      __ mov(temp2, temp);
+      __ StoreIntoObject(instance_reg,
+                         FieldAddress(instance_reg, field().Offset()),
+                         temp2);
+
+      __ Bind(&copy_double);
+      __ LoadDFromOffset(fpu_temp,
+                         value_reg,
+                         Double::value_offset() - kHeapObjectTag);
+      __ StoreDToOffset(fpu_temp, temp,
+                        Double::value_offset() - kHeapObjectTag);
+      __ b(&skip_store);
+    }
 
-    __ Bind(&copy_double);
-    __ LoadDFromOffset(fpu_temp,
-                       value_reg,
-                       Double::value_offset() - kHeapObjectTag);
-    __ StoreDToOffset(fpu_temp, temp, Double::value_offset() - kHeapObjectTag);
-    __ b(&skip_store);
     __ Bind(&store_pointer);
   }
 
@@ -2067,26 +2073,28 @@ void LoadFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
     // Fall through.
     __ b(&load_pointer);
 
-    __ Bind(&load_double);
-
-    BoxDoubleSlowPath* slow_path = new BoxDoubleSlowPath(this);
-    compiler->AddSlowPathCode(slow_path);
-
     if (!compiler->is_optimizing()) {
       locs()->live_registers()->Add(locs()->in(0));
     }
 
-    __ TryAllocate(compiler->double_class(),
-                   slow_path->entry_label(),
-                   result_reg,
-                   temp);
-    __ Bind(slow_path->exit_label());
-    __ lw(temp, FieldAddress(instance_reg, offset_in_bytes()));
-    __ LoadDFromOffset(value, temp, Double::value_offset() - kHeapObjectTag);
-    __ StoreDToOffset(value,
-                      result_reg,
-                      Double::value_offset() - kHeapObjectTag);
-    __ b(&done);
+    {
+      __ Bind(&load_double);
+      BoxDoubleSlowPath* slow_path = new BoxDoubleSlowPath(this);
+      compiler->AddSlowPathCode(slow_path);
+
+      __ TryAllocate(compiler->double_class(),
+                     slow_path->entry_label(),
+                     result_reg,
+                     temp);
+      __ Bind(slow_path->exit_label());
+      __ lw(temp, FieldAddress(instance_reg, offset_in_bytes()));
+      __ LoadDFromOffset(value, temp, Double::value_offset() - kHeapObjectTag);
+      __ StoreDToOffset(value,
+                        result_reg,
+                        Double::value_offset() - kHeapObjectTag);
+      __ b(&done);
+    }
+
     __ Bind(&load_pointer);
   }
   __ lw(result_reg, Address(instance_reg, offset_in_bytes() - kHeapObjectTag));