Adds muls, sdiv, udiv instructions to ARM simulator, assembler, disassembler

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 1978 matching lines @@
       if (instr->HasL()) {
         set_register(rd, ReadW(addr, instr));
       } 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();

[regis, 2013/03/05 19:11:34]

You need to test if rm is zero. In that case, the result should be set to zero,
assuming we expect IntegerZeroDivideTrappingEnabled() to be false. See spec.
We may behave differently if the default behavior on the target is different. I
would add a TODO(zra): Revisit once we test on ARM hardware.
In any case, we do not want the host to throw.

+  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;
+    set_register(rd, static_cast<int32_t>(result));
+  } else {
+    // signed division.
+    int32_t rn_val = get_register(rn);
+    int32_t rm_val = get_register(rm);
+    int32_t result = rn_val / rm_val;
+    set_register(rd, result);
+  }
+}
+
+
 void Simulator::DecodeType3(Instr* instr) {
+  if (instr->IsDivision()) {
+    DoDivision(instr);
+    return;
+  }
   Register rd = instr->RdField();
   Register rn = instr->RnField();
   int32_t rn_val = get_register(rn);
   bool shifter_carry_out = 0;
   int32_t shifter_operand = GetShiftRm(instr, &shifter_carry_out);
   uword addr = 0;
   bool write_back = false;
   switch (instr->PUField()) {
     case 0: {
       // Format(instr, "'memop'cond'b 'rd, ['rn], -'shift_rm");
@@ skipping 797 matching lines @@
   // isolate->ChangeStateToGeneratedCode();
   set_register(kExceptionObjectReg, bit_cast<int32_t>(object.raw()));
   buf->Longjmp();
 }
 
 }  // namespace dart
 
 #endif  // !defined(HOST_ARCH_ARM)
 
 #endif  // defined TARGET_ARCH_ARM