Introduce a lazy-compile stub for functions.

runtime/vm/flow_graph_compiler_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/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 1262 matching lines @@
   __ b(&update, NE);
 
   __ Bind(&call_target_function);
   // Call the target found in the cache.  For a class id match, this is a
   // proper target for the given name and arguments descriptor.  If the
   // illegal class id was found, the target is a cache miss handler that can
   // be invoked as a normal Dart function.
   __ add(IP, R2, ShifterOperand(R3, LSL, 2));
   __ ldr(R0, FieldAddress(IP, base + kWordSize));
   __ ldr(R1, FieldAddress(R0, Function::code_offset()));
-  if (FLAG_collect_code) {
-    // If we are collecting code, the code object may be null.
-    Label is_compiled;
-    __ CompareImmediate(R1, reinterpret_cast<intptr_t>(Object::null()));
-    __ b(&is_compiled, NE);
-    __ BranchLinkPatchable(&StubCode::CompileFunctionRuntimeCallLabel());
-    AddCurrentDescriptor(PcDescriptors::kRuntimeCall,
-                         Isolate::kNoDeoptId,
-                         token_pos);
-    RecordSafepoint(locs);
-    // R0: target function.
-    __ ldr(R1, FieldAddress(R0, Function::code_offset()));
-    __ Bind(&is_compiled);
-  }
-  __ ldr(R0, FieldAddress(R1, Code::instructions_offset()));
+  __ ldr(R1, FieldAddress(R1, Code::instructions_offset()));
   __ LoadObject(R5, ic_data);
   __ LoadObject(R4, arguments_descriptor);
-  __ AddImmediate(R0, Instructions::HeaderSize() - kHeapObjectTag);
-  __ blx(R0);
+  __ AddImmediate(R1, Instructions::HeaderSize() - kHeapObjectTag);
+  __ blx(R1);
   AddCurrentDescriptor(PcDescriptors::kOther, Isolate::kNoDeoptId, token_pos);
   RecordSafepoint(locs);
   AddDeoptIndexAtCall(Isolate::ToDeoptAfter(deopt_id), token_pos);
   __ Drop(argument_count);
 }
 
 
 void FlowGraphCompiler::EmitUnoptimizedStaticCall(
     const Function& target_function,
     const Array& arguments_descriptor,
@@ skipping 489 matching lines @@
   DRegister dreg = EvenDRegisterOf(reg);
   __ vldrd(dreg, Address(SP, kDoubleSize, Address::PostIndex));
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM