MIPS: Implement unaligned access instruction.

src/mips64/simulator-mips64.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.
 
 #include <limits.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #include <cmath>
 
 #if V8_TARGET_ARCH_MIPS64
@@ skipping 1725 matching lines @@
 // TODO(plind): sign-extend and zero-extend not implmented properly
 // on all the ReadXX functions, I don't think re-interpret cast does it.
 int32_t Simulator::ReadW(int64_t addr, Instruction* instr) {
   if (addr >=0 && addr < 0x400) {
     // This has to be a NULL-dereference, drop into debugger.
     PrintF("Memory read from bad address: 0x%08" PRIx64 " , pc=0x%08" PRIxPTR
            " \n",
            addr, reinterpret_cast<intptr_t>(instr));
     DieOrDebug();
   }
-  if ((addr & 0x3) == 0) {
+  if ((addr & 0x3) == 0 || kArchVariant == kMips64r6) {
     int32_t* ptr = reinterpret_cast<int32_t*>(addr);
     TraceMemRd(addr, static_cast<int64_t>(*ptr));
     return *ptr;
   }
   PrintF("Unaligned read at 0x%08" PRIx64 " , pc=0x%08" V8PRIxPTR "\n", addr,
          reinterpret_cast<intptr_t>(instr));
   DieOrDebug();
   return 0;
 }
 
 
 uint32_t Simulator::ReadWU(int64_t addr, Instruction* instr) {
   if (addr >=0 && addr < 0x400) {
     // This has to be a NULL-dereference, drop into debugger.
     PrintF("Memory read from bad address: 0x%08" PRIx64 " , pc=0x%08" PRIxPTR
            " \n",
            addr, reinterpret_cast<intptr_t>(instr));
     DieOrDebug();
   }
-  if ((addr & 0x3) == 0) {
+  if ((addr & 0x3) == 0 || kArchVariant == kMips64r6) {
     uint32_t* ptr = reinterpret_cast<uint32_t*>(addr);
     TraceMemRd(addr, static_cast<int64_t>(*ptr));
     return *ptr;
   }
   PrintF("Unaligned read at 0x%08" PRIx64 " , pc=0x%08" V8PRIxPTR "\n", addr,
          reinterpret_cast<intptr_t>(instr));
   DieOrDebug();
   return 0;
 }
 
 
 void Simulator::WriteW(int64_t addr, int32_t value, Instruction* instr) {
   if (addr >= 0 && addr < 0x400) {
     // This has to be a NULL-dereference, drop into debugger.
     PrintF("Memory write to bad address: 0x%08" PRIx64 " , pc=0x%08" PRIxPTR
            " \n",
            addr, reinterpret_cast<intptr_t>(instr));
     DieOrDebug();
   }
-  if ((addr & 0x3) == 0) {
+  if ((addr & 0x3) == 0 || kArchVariant == kMips64r6) {
     TraceMemWr(addr, value, WORD);
     int* ptr = reinterpret_cast<int*>(addr);
     *ptr = value;
     return;
   }
   PrintF("Unaligned write at 0x%08" PRIx64 " , pc=0x%08" V8PRIxPTR "\n", addr,
          reinterpret_cast<intptr_t>(instr));
   DieOrDebug();
 }
 
 
 int64_t Simulator::Read2W(int64_t addr, Instruction* instr) {
   if (addr >=0 && addr < 0x400) {
     // This has to be a NULL-dereference, drop into debugger.
     PrintF("Memory read from bad address: 0x%08" PRIx64 " , pc=0x%08" PRIxPTR
            " \n",
            addr, reinterpret_cast<intptr_t>(instr));
     DieOrDebug();
   }
-  if ((addr & kPointerAlignmentMask) == 0) {
+  if ((addr & kPointerAlignmentMask) == 0 || kArchVariant == kMips64r6) {
     int64_t* ptr = reinterpret_cast<int64_t*>(addr);
     TraceMemRd(addr, *ptr);
     return *ptr;
   }
   PrintF("Unaligned read at 0x%08" PRIx64 " , pc=0x%08" V8PRIxPTR "\n", addr,
          reinterpret_cast<intptr_t>(instr));
   DieOrDebug();
   return 0;
 }
 
 
 void Simulator::Write2W(int64_t addr, int64_t value, Instruction* instr) {
   if (addr >= 0 && addr < 0x400) {
     // This has to be a NULL-dereference, drop into debugger.
     PrintF("Memory write to bad address: 0x%08" PRIx64 " , pc=0x%08" PRIxPTR
            "\n",
            addr, reinterpret_cast<intptr_t>(instr));
     DieOrDebug();
   }
-  if ((addr & kPointerAlignmentMask) == 0) {
+  if ((addr & kPointerAlignmentMask) == 0 || kArchVariant == kMips64r6) {
     TraceMemWr(addr, value, DWORD);
     int64_t* ptr = reinterpret_cast<int64_t*>(addr);
     *ptr = value;
     return;
   }
   PrintF("Unaligned write at 0x%08" PRIx64 " , pc=0x%08" V8PRIxPTR "\n", addr,
          reinterpret_cast<intptr_t>(instr));
   DieOrDebug();
 }
 
 
 double Simulator::ReadD(int64_t addr, Instruction* instr) {
-  if ((addr & kDoubleAlignmentMask) == 0) {
+  if ((addr & kDoubleAlignmentMask) == 0 || kArchVariant == kMips64r6) {
     double* ptr = reinterpret_cast<double*>(addr);
     return *ptr;
   }
   PrintF("Unaligned (double) read at 0x%08" PRIx64 " , pc=0x%08" V8PRIxPTR "\n",
          addr, reinterpret_cast<intptr_t>(instr));
   base::OS::Abort();
   return 0;
 }
 
 
 void Simulator::WriteD(int64_t addr, double value, Instruction* instr) {
-  if ((addr & kDoubleAlignmentMask) == 0) {
+  if ((addr & kDoubleAlignmentMask) == 0 || kArchVariant == kMips64r6) {
     double* ptr = reinterpret_cast<double*>(addr);
     *ptr = value;
     return;
   }
   PrintF("Unaligned (double) write at 0x%08" PRIx64 " , pc=0x%08" V8PRIxPTR
          "\n",
          addr, reinterpret_cast<intptr_t>(instr));
   DieOrDebug();
 }
 
 
 uint16_t Simulator::ReadHU(int64_t addr, Instruction* instr) {
-  if ((addr & 1) == 0) {
+  if ((addr & 1) == 0 || kArchVariant == kMips64r6) {
     uint16_t* ptr = reinterpret_cast<uint16_t*>(addr);
     TraceMemRd(addr, static_cast<int64_t>(*ptr));
     return *ptr;
   }
   PrintF("Unaligned unsigned halfword read at 0x%08" PRIx64
          " , pc=0x%08" V8PRIxPTR "\n",
          addr, reinterpret_cast<intptr_t>(instr));
   DieOrDebug();
   return 0;
 }
 
 
 int16_t Simulator::ReadH(int64_t addr, Instruction* instr) {
-  if ((addr & 1) == 0) {
+  if ((addr & 1) == 0 || kArchVariant == kMips64r6) {
     int16_t* ptr = reinterpret_cast<int16_t*>(addr);
     TraceMemRd(addr, static_cast<int64_t>(*ptr));
     return *ptr;
   }
   PrintF("Unaligned signed halfword read at 0x%08" PRIx64
          " , pc=0x%08" V8PRIxPTR "\n",
          addr, reinterpret_cast<intptr_t>(instr));
   DieOrDebug();
   return 0;
 }
 
 
 void Simulator::WriteH(int64_t addr, uint16_t value, Instruction* instr) {
-  if ((addr & 1) == 0) {
+  if ((addr & 1) == 0 || kArchVariant == kMips64r6) {
     TraceMemWr(addr, value, HALF);
     uint16_t* ptr = reinterpret_cast<uint16_t*>(addr);
     *ptr = value;
     return;
   }
   PrintF("Unaligned unsigned halfword write at 0x%08" PRIx64
          " , pc=0x%08" V8PRIxPTR "\n",
          addr, reinterpret_cast<intptr_t>(instr));
   DieOrDebug();
 }
 
 
 void Simulator::WriteH(int64_t addr, int16_t value, Instruction* instr) {
-  if ((addr & 1) == 0) {
+  if ((addr & 1) == 0 || kArchVariant == kMips64r6) {
     TraceMemWr(addr, value, HALF);
     int16_t* ptr = reinterpret_cast<int16_t*>(addr);
     *ptr = value;
     return;
   }
   PrintF("Unaligned halfword write at 0x%08" PRIx64 " , pc=0x%08" V8PRIxPTR
          "\n",
          addr, reinterpret_cast<intptr_t>(instr));
   DieOrDebug();
 }
@@ skipping 2237 matching lines @@
   // Used for conditional branch instructions.
   bool execute_branch_delay_instruction = false;
 
   // Used for arithmetic instructions.
   int64_t alu_out = 0;
 
   // Used for memory instructions.
   int64_t addr = 0x0;
   // Alignment for 32-bit integers used in LWL, LWR, etc.
   const int kInt32AlignmentMask = sizeof(uint32_t) - 1;
+  // Alignment for 64-bit integers used in LDL, LDR, etc.
+  const int kInt64AlignmentMask = sizeof(uint64_t) - 1;
 
   // Branch instructions common part.
   auto BranchAndLinkHelper = [this, instr, &next_pc,
                               &execute_branch_delay_instruction](
       bool do_branch) {
     execute_branch_delay_instruction = true;
     int64_t current_pc = get_pc();
     if (do_branch) {
       int16_t imm16 = instr->Imm16Value();
       next_pc = current_pc + (imm16 << 2) + Instruction::kInstrSize;
@@ skipping 281 matching lines @@
       break;
     case LH:
       set_register(rt_reg, ReadH(rs + se_imm16, instr));
       break;
     case LWL: {
       // al_offset is offset of the effective address within an aligned word.
       uint8_t al_offset = (rs + se_imm16) & kInt32AlignmentMask;
       uint8_t byte_shift = kInt32AlignmentMask - al_offset;
       uint32_t mask = (1 << byte_shift * 8) - 1;
       addr = rs + se_imm16 - al_offset;
-      alu_out = ReadW(addr, instr);
-      alu_out <<= byte_shift * 8;
-      alu_out |= rt & mask;
-      set_register(rt_reg, alu_out);
+      int32_t val = ReadW(addr, instr);
+      val <<= byte_shift * 8;
+      val |= rt & mask;
+      set_register(rt_reg, static_cast<int64_t>(val));
       break;
     }
     case LW:
       set_register(rt_reg, ReadW(rs + se_imm16, instr));
       break;
     case LWU:
       set_register(rt_reg, ReadWU(rs + se_imm16, instr));
       break;
     case LD:
       set_register(rt_reg, Read2W(rs + se_imm16, instr));
       break;
     case LBU:
       set_register(rt_reg, ReadBU(rs + se_imm16));
       break;
     case LHU:
       set_register(rt_reg, ReadHU(rs + se_imm16, instr));
       break;
     case LWR: {
       // al_offset is offset of the effective address within an aligned word.
       uint8_t al_offset = (rs + se_imm16) & kInt32AlignmentMask;
       uint8_t byte_shift = kInt32AlignmentMask - al_offset;
       uint32_t mask = al_offset ? (~0 << (byte_shift + 1) * 8) : 0;
       addr = rs + se_imm16 - al_offset;
       alu_out = ReadW(addr, instr);
       alu_out = static_cast<uint32_t> (alu_out) >> al_offset * 8;
       alu_out |= rt & mask;
       set_register(rt_reg, alu_out);
       break;
     }
+    case LDL: {
+      // al_offset is offset of the effective address within an aligned word.
+      uint8_t al_offset = (rs + se_imm16) & kInt64AlignmentMask;
+      uint8_t byte_shift = kInt64AlignmentMask - al_offset;
+      uint64_t mask = (1UL << byte_shift * 8) - 1;
+      addr = rs + se_imm16 - al_offset;
+      alu_out = Read2W(addr, instr);
+      alu_out <<= byte_shift * 8;
+      alu_out |= rt & mask;
+      set_register(rt_reg, alu_out);
+      break;
+    }
+    case LDR: {
+      // al_offset is offset of the effective address within an aligned word.
+      uint8_t al_offset = (rs + se_imm16) & kInt64AlignmentMask;
+      uint8_t byte_shift = kInt64AlignmentMask - al_offset;
+      uint64_t mask = al_offset ? (~0UL << (byte_shift + 1) * 8) : 0UL;
+      addr = rs + se_imm16 - al_offset;
+      alu_out = Read2W(addr, instr);
+      alu_out = alu_out >> al_offset * 8;
+      alu_out |= rt & mask;
+      set_register(rt_reg, alu_out);
+      break;
+    }
     case SB:
       WriteB(rs + se_imm16, static_cast<int8_t>(rt));
       break;
     case SH:
       WriteH(rs + se_imm16, static_cast<uint16_t>(rt), instr);
       break;
     case SWL: {
       uint8_t al_offset = (rs + se_imm16) & kInt32AlignmentMask;
       uint8_t byte_shift = kInt32AlignmentMask - al_offset;
       uint32_t mask = byte_shift ? (~0 << (al_offset + 1) * 8) : 0;
@@ skipping 11 matching lines @@
       break;
     case SWR: {
       uint8_t al_offset = (rs + se_imm16) & kInt32AlignmentMask;
       uint32_t mask = (1 << al_offset * 8) - 1;
       addr = rs + se_imm16 - al_offset;
       uint64_t mem_value = ReadW(addr, instr);
       mem_value = (rt << al_offset * 8) | (mem_value & mask);
       WriteW(addr, static_cast<int32_t>(mem_value), instr);
       break;
     }
+    case SDL: {
+      uint8_t al_offset = (rs + se_imm16) & kInt64AlignmentMask;
+      uint8_t byte_shift = kInt64AlignmentMask - al_offset;
+      uint64_t mask = byte_shift ? (~0UL << (al_offset + 1) * 8) : 0;
+      addr = rs + se_imm16 - al_offset;
+      uint64_t mem_value = Read2W(addr, instr) & mask;
+      mem_value |= rt >> byte_shift * 8;
+      Write2W(addr, mem_value, instr);
+      break;
+    }
+    case SDR: {
+      uint8_t al_offset = (rs + se_imm16) & kInt64AlignmentMask;
+      uint64_t mask = (1UL << al_offset * 8) - 1;
+      addr = rs + se_imm16 - al_offset;
+      uint64_t mem_value = Read2W(addr, instr);
+      mem_value = (rt << al_offset * 8) | (mem_value & mask);
+      Write2W(addr, mem_value, instr);
+      break;
+    }
     case LWC1:
       set_fpu_register(ft_reg, kFPUInvalidResult);  // Trash upper 32 bits.
       set_fpu_register_word(ft_reg, ReadW(rs + se_imm16, instr));
       break;
     case LDC1:
       set_fpu_register_double(ft_reg, ReadD(rs + se_imm16, instr));
       break;
     case SWC1: {
       int32_t alu_out_32 = static_cast<int32_t>(get_fpu_register(ft_reg));
       WriteW(rs + se_imm16, alu_out_32, instr);
@@ skipping 350 matching lines @@
 }
 
 
 #undef UNSUPPORTED
 }  // namespace internal
 }  // namespace v8
 
 #endif  // USE_SIMULATOR
 
 #endif  // V8_TARGET_ARCH_MIPS64