Reland of [turbofan] ARM: Implement vswp and use in gap resolver

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 1807 matching lines @@
     case 7:
       if ((instr->Bits(18, 16) == 0) && (instr->Bits(11, 6) == 0x28) &&
           (instr->Bit(4) == 1)) {
         // vmovl unsigned
         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);
         out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
                                     "vmovl.u%d q%d, d%d", imm3*8, Vd, Vm);
+      } else if ((instr->Bits(21, 16) == 0x32) && (instr->Bits(11, 7) == 0) &&
+                 (instr->Bit(4) == 0)) {
+        int Vd = instr->VFPDRegValue(kDoublePrecision);
+        int Vm = instr->VFPMRegValue(kDoublePrecision);
+        char rtype = (instr->Bit(6) == 0) ? 'd' : 'q';
+        out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
+                                    "vswp %c%d, %c%d", rtype, Vd, rtype, Vm);
       } else {
         Unknown(instr);
       }
       break;
     case 8:
       if (instr->Bits(21, 20) == 0) {
         // vst1
         int Vd = (instr->Bit(22) << 4) | instr->VdValue();
         int Rn = instr->VnValue();
         int type = instr->Bits(11, 8);
@@ skipping 325 matching lines @@
     pc += d.InstructionDecode(buffer, pc);
     v8::internal::PrintF(f, "%p    %08x      %s\n", static_cast<void*>(prev_pc),
                          *reinterpret_cast<int32_t*>(prev_pc), buffer.start());
   }
 }
 
 
 }  // namespace disasm
 
 #endif  // V8_TARGET_ARCH_ARM