Write-barrier verification on ARM.

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"
 #include "vm/compiler.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
 #include "vm/deopt_instructions.h"
 #include "vm/il_printer.h"
 #include "vm/locations.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
 #include "vm/stack_frame.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
+#include "vm/verified_memory.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, trap_on_deoptimization, false, "Trap on deoptimization.");
 DEFINE_FLAG(bool, unbox_mints, true, "Optimize 64-bit integer arithmetic.");
 DEFINE_FLAG(bool, unbox_doubles, true, "Optimize double arithmetic.");
 DECLARE_FLAG(bool, enable_type_checks);
 DECLARE_FLAG(bool, enable_simd_inline);
 
 
@@ skipping 1156 matching lines @@
 void FlowGraphCompiler::EmitEdgeCounter() {
   // We do not check for overflow when incrementing the edge counter.  The
   // function should normally be optimized long before the counter can
   // overflow; and though we do not reset the counters when we optimize or
   // deoptimize, there is a bound on the number of
   // optimization/deoptimization cycles we will attempt.
   const Array& counter = Array::ZoneHandle(Array::New(1, Heap::kOld));
   counter.SetAt(0, Smi::Handle(Smi::New(0)));
   __ Comment("Edge counter");
   __ LoadObject(R0, counter);
+#if defined(DEBUG)
+  intptr_t increment_start = assembler_->CodeSize();
+#endif  // DEBUG
   __ ldr(IP, FieldAddress(R0, Array::element_offset(0)));
   __ add(IP, IP, Operand(Smi::RawValue(1)));
-  __ str(IP, FieldAddress(R0, Array::element_offset(0)));
+  __ StoreIntoSmiField(FieldAddress(R0, Array::element_offset(0)), IP);
+#if defined(DEBUG)
+  // If the assertion below fails, update EdgeCounterIncrementSizeInBytes.
+  intptr_t expected = EdgeCounterIncrementSizeInBytes();
+  intptr_t actual = assembler_->CodeSize() - increment_start;
+  if (actual != expected) {
+    FATAL2("Edge counter increment length: %" Pd ", expected %" Pd "\n",
+           actual,
+           expected);
+  }
+#endif  // DEBUG
+}
+
+
+int32_t FlowGraphCompiler::EdgeCounterIncrementSizeInBytes() {
+  // Used by CodePatcher; so must be constant across all code in an isolate.
+#if defined(DEBUG)
+  return (VerifiedMemory::enabled() ? 34 : 15) * Instr::kInstrSize;
+#else
+  return return 3 * Instr::kInstrSize;
+#endif  // DEBUG
 }
 
 
 void FlowGraphCompiler::EmitOptimizedInstanceCall(
     ExternalLabel* target_label,
     const ICData& ic_data,
     intptr_t argument_count,
     intptr_t deopt_id,
     intptr_t token_pos,
     LocationSummary* locs) {
@@ skipping 621 matching lines @@
   DRegister dreg = EvenDRegisterOf(reg);
   __ vldrd(dreg, Address(SP, kDoubleSize, Address::PostIndex));
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM