[Atomics] code stubs for atomic operations

src/arm/disasm-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // A Disassembler object is used to disassemble a block of code instruction by
 // instruction. The default implementation of the NameConverter object can be
 // overriden to modify register names or to do symbol lookup on addresses.
 //
 // The example below will disassemble a block of code and print it to stdout.
 //
@@ skipping 1671 matching lines @@
       }
       default:
         Unknown(instr);  // Not used by V8.
     }
   } else {
     Unknown(instr);  // Not used by V8.
   }
 }
 
 
+static const char* const barrier_option_names[] = {
+    "invalid", "oshld", "oshst", "osh", "invalid", "nshld", "nshst", "nsh",
+    "invalid", "ishld", "ishst", "ish", "invalid", "ld",    "st",    "sy",
+};
+
+
 void Decoder::DecodeSpecialCondition(Instruction* instr) {
   switch (instr->SpecialValue()) {
     case 5:
       if ((instr->Bits(18, 16) == 0) && (instr->Bits(11, 6) == 0x28) &&
           (instr->Bit(4) == 1)) {
         // vmovl signed
         if ((instr->VdValue() & 1) != 0) Unknown(instr);
         int Vd = (instr->Bit(22) << 3) | (instr->VdValue() >> 1);
         int Vm = (instr->Bit(5) << 4) | instr->VmValue();
         int imm3 = instr->Bits(21, 19);
@@ skipping 56 matching lines @@
         if (offset == 0) {
           out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
                                       "pld [r%d]", Rn);
         } else if (instr->Bit(23) == 0) {
           out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
                                       "pld [r%d, #-%d]", Rn, offset);
         } else {
           out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
                                       "pld [r%d, #+%d]", Rn, offset);
         }
+      } else if (instr->SpecialValue() == 0xA && instr->Bits(22, 20) == 7) {
+        int option = instr->Bits(3, 0);
+        switch (instr->Bits(7, 4)) {
+          case 4:
+            out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
+                                        "dsb %s", barrier_option_names[option]);
+            break;
+          case 5:
+            out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
+                                        "dmb %s", barrier_option_names[option]);
+            break;
+          case 6:
+            out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
+                                        "isb %s", barrier_option_names[option]);
+            break;
+          default:
+            Unknown(instr);
+        }
       } else {
         Unknown(instr);
       }
       break;
     case 0x1D:
       if (instr->Opc1Value() == 0x7 && instr->Bits(19, 18) == 0x2 &&
           instr->Bits(11, 9) == 0x5 && instr->Bits(7, 6) == 0x1 &&
           instr->Bit(4) == 0x0) {
         // VRINTA, VRINTN, VRINTP, VRINTM (floating-point)
         bool dp_operation = (instr->SzValue() == 1);
@@ skipping 200 matching lines @@
     v8::internal::PrintF(
         f, "%p    %08x      %s\n",
         prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer.start());
   }
 }
 
 
 }  // namespace disasm
 
 #endif  // V8_TARGET_ARCH_ARM