Runtime support for evaluation of static field initializer expressions

runtime/vm/intermediate_language_arm.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM.
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/cpu.h"
@@ skipping 2614 matching lines @@
   __ LoadImmediate(R1, num_context_variables());
   StubCode* stub_code = compiler->isolate()->stub_code();
   const ExternalLabel label(stub_code->AllocateContextEntryPoint());
   compiler->GenerateCall(token_pos(),
                          &label,
                          RawPcDescriptors::kOther,
                          locs());
 }
 
 
+LocationSummary* InitStaticFieldInstr::MakeLocationSummary(Isolate* isolate,
+                                                           bool opt) const {
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 1;
+  LocationSummary* locs = new(isolate) LocationSummary(
+      isolate, kNumInputs, kNumTemps, LocationSummary::kCall);
+  locs->set_in(0, Location::RegisterLocation(R0));
+  locs->set_out(0, Location::RegisterLocation(R0));

[srdjan, 2014/08/19 18:49:39]

You do not need output .. here and elsewhere..

[hausner, 2014/08/19 20:54:00]

Done.

+  locs->set_temp(0, Location::RegisterLocation(R1));

[zra, 2014/08/18 15:56:09]

Why does the temp register need to be hardcoded to R1? Same question for other
architectures.

[zra, 2014/08/18 17:15:53]

Nevermind. Looks like for kCall LocationSummary, you always have to hardcode the
registers.

[hausner, 2014/08/19 17:19:14]

I initially tried to use Location::RequiresRegister() but that results in an
assertion, probably because of the reason you mention.

On 2014/08/18 17:15:53, zra wrote:

+  return locs;
+}
+
+
+void InitStaticFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Register field = locs()->in(0).reg();
+  Register temp = locs()->temp(0).reg();
+  Label call_runtime, no_call;
+
+  __ ldr(temp, FieldAddress(field, Field::value_offset()));
+  __ CompareObject(temp, Object::sentinel());
+  __ b(&call_runtime, EQ);
+
+  __ CompareObject(temp, Object::transition_sentinel());
+  __ b(&no_call, NE);
+
+  __ Bind(&call_runtime);
+  __ PushObject(Object::null_object());  // Make room for (unused) result.
+  __ Push(field);
+  compiler->GenerateRuntimeCall(token_pos(),
+                                deopt_id(),
+                                kInitStaticFieldRuntimeEntry,
+                                1,
+                                locs());
+  __ Drop(2);  // Remove argument and result placeholder.
+  __ Bind(&no_call);
+}
+
+
 LocationSummary* CloneContextInstr::MakeLocationSummary(Isolate* isolate,
                                                         bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* locs = new(isolate) LocationSummary(
       isolate, kNumInputs, kNumTemps, LocationSummary::kCall);
   locs->set_in(0, Location::RegisterLocation(R0));
   locs->set_out(0, Location::RegisterLocation(R0));
   return locs;
 }
@@ skipping 4065 matching lines @@
   compiler->GenerateCall(token_pos(), &label, stub_kind_, locs());
 #if defined(DEBUG)
   __ LoadImmediate(R4, kInvalidObjectPointer);
   __ LoadImmediate(R5, kInvalidObjectPointer);
 #endif
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM