VM: Explicitly load function and context before calling a closure.

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/dart_entry.h"
@@ skipping 164 matching lines @@
         Smi::RawValue(true_value) - Smi::RawValue(false_value);
     __ AndImmediate(result, result, val);
     if (false_value != 0) {
       __ AddImmediate(result, Smi::RawValue(false_value));
     }
   }
 }
 
 
 LocationSummary* ClosureCallInstr::MakeLocationSummary(bool opt) const {
-  return MakeCallSummary();
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* summary =
+      new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
+  summary->set_in(0, Location::RegisterLocation(R0));  // Function.
+  summary->set_out(0, Location::RegisterLocation(R0));
+  return summary;
 }
 
 
 void ClosureCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  // Load closure object (first argument) in R1.
+  // Load arguments descriptor in R4.
   int argument_count = ArgumentCount();
-  __ ldr(R1, Address(SP, (argument_count - 1) * kWordSize));
-
-  // Load arguments descriptor in R4.
   const Array& arguments_descriptor =
       Array::ZoneHandle(ArgumentsDescriptor::New(argument_count,
                                                  argument_names()));
   __ LoadObject(R4, arguments_descriptor);
 
-  // Load the closure function into R0.
-  __ ldr(R0, FieldAddress(R1, Closure::function_offset()));
-
-  // Load closure context in CTX; note that CTX has already been preserved.
-  __ ldr(CTX, FieldAddress(R1, Closure::context_offset()));
-
   // R4: Arguments descriptor.
   // R0: Function.
+  ASSERT(locs()->in(0).reg() == R0);
   __ ldr(R2, FieldAddress(R0, Function::code_offset()));
 
   // R2: code.
   // R5: Smi 0 (no IC data; the lazy-compile stub expects a GC-safe value).
   __ LoadImmediate(R5, 0);
   __ ldr(R2, FieldAddress(R2, Code::instructions_offset()));
   __ AddImmediate(R2, Instructions::HeaderSize() - kHeapObjectTag);
   __ blx(R2);
   compiler->AddCurrentDescriptor(PcDescriptors::kClosureCall,
                                  deopt_id(),
                                  token_pos());
   compiler->RecordSafepoint(locs());
   // Marks either the continuation point in unoptimized code or the
   // deoptimization point in optimized code, after call.
   const intptr_t deopt_id_after = Isolate::ToDeoptAfter(deopt_id());
   if (compiler->is_optimizing()) {
-    compiler->AddDeoptIndexAtCall(deopt_id_after, token_pos());
+    compiler->AddDeoptIndexAtCall(deopt_id_after, token_pos(), InputCount());
   } else {
     // Add deoptimization continuation point after the call and before the
     // arguments are removed.
     compiler->AddCurrentDescriptor(PcDescriptors::kDeopt,
                                    deopt_id_after,
                                    token_pos());
   }
   __ Drop(argument_count);
 }
 
@@ skipping 5786 matching lines @@
   compiler->GenerateCall(token_pos(),
                          &label,
                          PcDescriptors::kOther,
                          locs());
   __ Drop(ArgumentCount());  // Discard arguments.
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM