Fixes for integer division on ARM hardware so that assembler tests pass.

runtime/vm/simulator_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 <math.h>  // for isnan.
 #include <setjmp.h>
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_ARM)
@@ skipping 1464 matching lines @@
           ASSERT(instr->Bits(21, 2) == 0x1);
           // Format(instr, "blx'cond 'rm");
           Register rm = instr->RmField();
           int32_t rm_val = get_register(rm);
           intptr_t pc = get_pc();
           set_register(LR, pc + Instr::kInstrSize);
           set_pc(rm_val);
           break;
         }
         case 7: {
-          if (instr->Bits(21, 2) == 0x1) {
-            // Format(instr, "bkpt'cond #'imm12_4");
+          if ((instr->Bits(21, 2) == 0x1) && (instr->ConditionField() == AL)) {
+            // Format(instr, "bkpt #'imm12_4");
             SimulatorDebugger dbg(this);
             set_pc(get_pc() + Instr::kInstrSize);
             char buffer[32];
             snprintf(buffer, sizeof(buffer), "bkpt #0x%x", instr->BkptField());
             dbg.Stop(instr, buffer);
           } else {
              // Format(instr, "smc'cond");
             UnimplementedInstruction(instr);
           }
           break;
@@ skipping 563 matching lines @@
       } else {
         WriteW(addr, get_register(rd), instr);
       }
     }
   }
 }
 
 
 void Simulator::DoDivision(Instr* instr) {
   ASSERT(CPUFeatures::integer_division_supported());
-  Register rd = instr->RdField();
-  Register rn = instr->RnField();
-  Register rm = instr->RmField();
+  Register rd = instr->DivRdField();
+  Register rn = instr->DivRnField();
+  Register rm = instr->DivRmField();
 
-  // TODO(zra): Does the hardware trap on divide-by-zero?
-  //     Revisit when we test on ARM hardware.
+  // ARMv7-a does not trap on divide-by-zero. The destination register is just
+  // set to 0.
   if (get_register(rm) == 0) {
     set_register(rd, 0);
     return;
   }
 
   if (instr->Bit(21) == 1) {
     // unsigned division.
     uint32_t rn_val = static_cast<uint32_t>(get_register(rn));
     uint32_t rm_val = static_cast<uint32_t>(get_register(rm));
     uint32_t result = rn_val / rm_val;
@@ skipping 836 matching lines @@
     set_register(kStackTraceObjectReg, bit_cast<int32_t>(raw_stacktrace));
   }
   buf->Longjmp();
 }
 
 }  // namespace dart
 
 #endif  // !defined(HOST_ARCH_ARM)
 
 #endif  // defined TARGET_ARCH_ARM