Optimize AOT's switchable calls for the monomorphic case.

runtime/vm/assembler_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"  // NOLINT
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/longjump.h"
@@ skipping 3219 matching lines @@
 void Assembler::EnterStubFrame() {
   EnterDartFrame(0);
 }
 
 
 void Assembler::LeaveStubFrame() {
   LeaveDartFrame();
 }
 
 
+void Assembler::NoMonomorphicCheckedEntry() {
+  buffer_.Reset();
+  bkpt(0);
+  bkpt(0);
+  bkpt(0);
+  ASSERT(CodeSize() == Instructions::kCheckedEntryOffset);
+}
+
+
+// R0 receiver, R9 guarded cid as Smi
+void Assembler::MonomorphicCheckedEntry() {
+#if defined(TESTING) || defined(DEBUG)
+  bool saved_use_far_branches = use_far_branches();
+  set_use_far_branches(false);
+#endif
+
+  Label miss;
+  Bind(&miss);
+  ldr(CODE_REG, Address(THR, Thread::monomorphic_miss_stub_offset()));
+  ldr(IP, FieldAddress(CODE_REG, Code::entry_point_offset()));
+  bx(IP);
+
+  Comment("MonomorphicCheckedEntry");
+  ASSERT(CodeSize() == Instructions::kCheckedEntryOffset);
+  LoadClassIdMayBeSmi(R4, R0);
+  SmiUntag(R9);
+  cmp(R4, Operand(R9));
+  b(&miss, NE);
+
+  // Fall through to unchecked entry.
+  ASSERT(CodeSize() == Instructions::kUncheckedEntryOffset);
+
+#if defined(TESTING) || defined(DEBUG)
+  set_use_far_branches(saved_use_far_branches);
+#endif
+}
+
+
 #ifndef PRODUCT
 void Assembler::MaybeTraceAllocation(intptr_t cid,
                                      Register temp_reg,
                                      Label* trace) {
   LoadAllocationStatsAddress(temp_reg, cid);
   const uword state_offset = ClassHeapStats::state_offset();
   ldr(temp_reg, Address(temp_reg, state_offset));
   tst(temp_reg, Operand(ClassHeapStats::TraceAllocationMask()));
   b(trace, NE);
 }
@@ skipping 258 matching lines @@
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfFpuRegisters));
   return fpu_reg_names[reg];
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM