VM: New calling convention for generated code.

runtime/vm/instructions_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 "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM.
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/constants_arm.h"
 #include "vm/cpu.h"
 #include "vm/instructions.h"
 #include "vm/object.h"
 
 namespace dart {
 
 CallPattern::CallPattern(uword pc, const Code& code)
     : object_pool_(ObjectPool::Handle(code.GetObjectPool())),
       end_(pc),
       ic_data_load_end_(0),
-      target_address_pool_index_(-1),
+      target_code_pool_index_(-1),
       ic_data_(ICData::Handle()) {
   ASSERT(code.ContainsInstructionAt(pc));
   // Last instruction: blx lr.
   ASSERT(*(reinterpret_cast<uword*>(end_) - 1) == 0xe12fff3e);
 
   Register reg;
   ic_data_load_end_ =
-      InstructionPattern::DecodeLoadWordFromPool(end_ - Instr::kInstrSize,
+      InstructionPattern::DecodeLoadWordFromPool(end_ - 2 * Instr::kInstrSize,
                                                  &reg,
-                                                 &target_address_pool_index_);
-  ASSERT(reg == LR);
+                                                 &target_code_pool_index_);
+  ASSERT(reg == CODE_REG);
 }
 
 
-int CallPattern::LengthInBytes() {
+int CallPattern::DeoptCallPatternLengthInBytes() {
   const ARMVersion version = TargetCPUFeatures::arm_version();
   if ((version == ARMv5TE) || (version == ARMv6)) {
     return 5 * Instr::kInstrSize;
   } else {
     ASSERT(version == ARMv7);
     return 3 * Instr::kInstrSize;
   }
 }
 
 
 NativeCallPattern::NativeCallPattern(uword pc, const Code& code)
     : object_pool_(ObjectPool::Handle(code.GetObjectPool())),
       end_(pc),
       native_function_pool_index_(-1),
-      target_address_pool_index_(-1) {
+      target_code_pool_index_(-1) {
   ASSERT(code.ContainsInstructionAt(pc));
   // Last instruction: blx lr.
   ASSERT(*(reinterpret_cast<uword*>(end_) - 1) == 0xe12fff3e);
 
   Register reg;
   uword native_function_load_end =
-      InstructionPattern::DecodeLoadWordFromPool(end_ - Instr::kInstrSize,
+      InstructionPattern::DecodeLoadWordFromPool(end_ - 2 * Instr::kInstrSize,
                                                  &reg,
-                                                 &target_address_pool_index_);
-  ASSERT(reg == LR);
+                                                 &target_code_pool_index_);
+  ASSERT(reg == CODE_REG);
   InstructionPattern::DecodeLoadWordFromPool(native_function_load_end,
                                              &reg,
                                              &native_function_pool_index_);
   ASSERT(reg == R5);
 }
 
 
-uword NativeCallPattern::target() const {
-  return object_pool_.RawValueAt(target_address_pool_index_);
+RawCode* NativeCallPattern::target() const {
+  return reinterpret_cast<RawCode*>(
+      object_pool_.ObjectAt(target_code_pool_index_));
 }
 
 
-void NativeCallPattern::set_target(uword target_address) const {
-  object_pool_.SetRawValueAt(target_address_pool_index_, target_address);
+void NativeCallPattern::set_target(const Code& new_target) const {
+  object_pool_.SetObjectAt(target_code_pool_index_, new_target);
   // No need to flush the instruction cache, since the code is not modified.
 }
 
 
 NativeFunction NativeCallPattern::native_function() const {
   return reinterpret_cast<NativeFunction>(
       object_pool_.RawValueAt(native_function_pool_index_));
 }
 
 
@@ skipping 83 matching lines @@
 // sequence is the instruction before the one at end).  Returns a pointer to
 // the first instruction in the sequence.  Returns the register being loaded
 // and the index in the pool being read from in the output parameters 'reg'
 // and 'index' respectively.
 uword InstructionPattern::DecodeLoadWordFromPool(uword end,
                                                  Register* reg,
                                                  intptr_t* index) {
   uword start = end - Instr::kInstrSize;
   int32_t instr = Instr::At(start)->InstructionBits();
   intptr_t offset = 0;
-  if ((instr & 0xffff0000) == 0xe59a0000) {  // ldr reg, [pp, #+offset]
+  if ((instr & 0xffff0000) == 0xe5990000) {  // ldr reg, [pp, #+offset]
     offset = instr & 0xfff;
     *reg = static_cast<Register>((instr & 0xf000) >> 12);
   } else {
     ASSERT((instr & 0xfff00000) == 0xe5900000);  // ldr reg, [reg, #+offset]
     offset = instr & 0xfff;
     start -= Instr::kInstrSize;
     instr = Instr::At(start)->InstructionBits();
-    if ((instr & 0xffff0000) == 0xe28a0000) {  // add reg, pp, operand
+    if ((instr & 0xffff0000) == 0xe2890000) {  // add reg, pp, operand
       const intptr_t rot = (instr & 0xf00) >> 7;
       const intptr_t imm8 = instr & 0xff;
       offset += (imm8 >> rot) | (imm8 << (32 - rot));
       *reg = static_cast<Register>((instr & 0xf000) >> 12);
     } else {
-      ASSERT((instr & 0xffff0000) == 0xe08a0000);  // add reg, pp, reg
+      ASSERT((instr & 0xffff0000) == 0xe0890000);  // add reg, pp, reg
       end = DecodeLoadWordImmediate(end, reg, &offset);
     }
   }
   *index = ObjectPool::IndexFromOffset(offset);
   return start;
 }
 
 
 RawICData* CallPattern::IcData() {
   if (ic_data_.IsNull()) {
     Register reg;
     InstructionPattern::DecodeLoadObject(ic_data_load_end_,
                                          object_pool_,
                                          &reg,
                                          &ic_data_);
     ASSERT(reg == R5);
   }
   return ic_data_.raw();
 }
 
 
-uword CallPattern::TargetAddress() const {
-  return object_pool_.RawValueAt(target_address_pool_index_);
+RawCode* CallPattern::TargetCode() const {
+  return reinterpret_cast<RawCode*>(
+      object_pool_.ObjectAt(target_code_pool_index_));
 }
 
 
-void CallPattern::SetTargetAddress(uword target_address) const {
-  object_pool_.SetRawValueAt(target_address_pool_index_, target_address);
-  // No need to flush the instruction cache, since the code is not modified.
+void CallPattern::SetTargetCode(const Code& target_code) const {
+  object_pool_.SetObjectAt(target_code_pool_index_, target_code);
 }
 
 
-void CallPattern::InsertAt(uword pc, uword target_address) {
+void CallPattern::InsertDeoptCallAt(uword pc, uword target_address) {
   const ARMVersion version = TargetCPUFeatures::arm_version();
   if ((version == ARMv5TE) || (version == ARMv6)) {
     const uint32_t byte0 = (target_address & 0x000000ff);
     const uint32_t byte1 = (target_address & 0x0000ff00) >> 8;
     const uint32_t byte2 = (target_address & 0x00ff0000) >> 16;
     const uint32_t byte3 = (target_address & 0xff000000) >> 24;
 
     const uword mov_ip = 0xe3a0c400 | byte3;  // mov ip, (byte3 rot 4)
     const uword or1_ip = 0xe38cc800 | byte2;  // orr ip, ip, (byte2 rot 8)
     const uword or2_ip = 0xe38ccc00 | byte1;  // orr ip, ip, (byte1 rot 12)
     const uword or3_ip = 0xe38cc000 | byte0;  // orr ip, ip, byte0
     const uword blx_ip = 0xe12fff3c;
 
     *reinterpret_cast<uword*>(pc + (0 * Instr::kInstrSize)) = mov_ip;
     *reinterpret_cast<uword*>(pc + (1 * Instr::kInstrSize)) = or1_ip;
     *reinterpret_cast<uword*>(pc + (2 * Instr::kInstrSize)) = or2_ip;
     *reinterpret_cast<uword*>(pc + (3 * Instr::kInstrSize)) = or3_ip;
     *reinterpret_cast<uword*>(pc + (4 * Instr::kInstrSize)) = blx_ip;
 
-    ASSERT(LengthInBytes() == 5 * Instr::kInstrSize);
-    CPU::FlushICache(pc, LengthInBytes());
+    ASSERT(DeoptCallPatternLengthInBytes() == 5 * Instr::kInstrSize);
+    CPU::FlushICache(pc, DeoptCallPatternLengthInBytes());
   } else {
     ASSERT(version == ARMv7);
     const uint16_t target_lo = target_address & 0xffff;
     const uint16_t target_hi = target_address >> 16;
 
     const uword movw_ip =
         0xe300c000 | ((target_lo >> 12) << 16) | (target_lo & 0xfff);
     const uword movt_ip =
         0xe340c000 | ((target_hi >> 12) << 16) | (target_hi & 0xfff);
     const uword blx_ip = 0xe12fff3c;
 
     *reinterpret_cast<uword*>(pc + (0 * Instr::kInstrSize)) = movw_ip;
     *reinterpret_cast<uword*>(pc + (1 * Instr::kInstrSize)) = movt_ip;
     *reinterpret_cast<uword*>(pc + (2 * Instr::kInstrSize)) = blx_ip;
 
-    ASSERT(LengthInBytes() == 3 * Instr::kInstrSize);
-    CPU::FlushICache(pc, LengthInBytes());
+    ASSERT(DeoptCallPatternLengthInBytes() == 3 * Instr::kInstrSize);
+    CPU::FlushICache(pc, DeoptCallPatternLengthInBytes());
   }
 }
 
-
-JumpPattern::JumpPattern(uword pc, const Code& code) : pc_(pc) { }
-
-
-int JumpPattern::pattern_length_in_bytes() {
-  const ARMVersion version = TargetCPUFeatures::arm_version();
-  if ((version == ARMv5TE) || (version == ARMv6)) {
-    return 5 * Instr::kInstrSize;
-  } else {
-    ASSERT(version == ARMv7);
-    return 3 * Instr::kInstrSize;
-  }
-}
-
-
-bool JumpPattern::IsValid() const {
-  const ARMVersion version = TargetCPUFeatures::arm_version();
-  if ((version == ARMv5TE) || (version == ARMv6)) {
-    Instr* mov_ip = Instr::At(pc_ + (0 * Instr::kInstrSize));
-    Instr* or1_ip = Instr::At(pc_ + (1 * Instr::kInstrSize));
-    Instr* or2_ip = Instr::At(pc_ + (2 * Instr::kInstrSize));
-    Instr* or3_ip = Instr::At(pc_ + (3 * Instr::kInstrSize));
-    Instr* bx_ip = Instr::At(pc_ + (4 * Instr::kInstrSize));
-    return ((mov_ip->InstructionBits() & 0xffffff00) == 0xe3a0c400) &&
-           ((or1_ip->InstructionBits() & 0xffffff00) == 0xe38cc800) &&
-           ((or2_ip->InstructionBits() & 0xffffff00) == 0xe38ccc00) &&
-           ((or3_ip->InstructionBits() & 0xffffff00) == 0xe38cc000) &&
-           ((bx_ip->InstructionBits() & 0xffffffff) == 0xe12fff1c);
-  } else {
-    ASSERT(version == ARMv7);
-    Instr* movw_ip = Instr::At(pc_ + (0 * Instr::kInstrSize));  // target_lo
-    Instr* movt_ip = Instr::At(pc_ + (1 * Instr::kInstrSize));  // target_hi
-    Instr* bx_ip = Instr::At(pc_ + (2 * Instr::kInstrSize));
-    return (movw_ip->InstructionBits() & 0xfff0f000) == 0xe300c000 &&
-           (movt_ip->InstructionBits() & 0xfff0f000) == 0xe340c000 &&
-           (bx_ip->InstructionBits() & 0xffffffff) == 0xe12fff1c;
-  }
-}
-
-
-uword JumpPattern::TargetAddress() const {
-  const ARMVersion version = TargetCPUFeatures::arm_version();
-  if ((version == ARMv5TE) || (version == ARMv6)) {
-    Instr* mov_ip = Instr::At(pc_ + (0 * Instr::kInstrSize));
-    Instr* or1_ip = Instr::At(pc_ + (1 * Instr::kInstrSize));
-    Instr* or2_ip = Instr::At(pc_ + (2 * Instr::kInstrSize));
-    Instr* or3_ip = Instr::At(pc_ + (3 * Instr::kInstrSize));
-    uword imm = 0;
-    imm |= or3_ip->Immed8Field();
-    imm |= or2_ip->Immed8Field() << 8;
-    imm |= or1_ip->Immed8Field() << 16;
-    imm |= mov_ip->Immed8Field() << 24;
-    return imm;
-  } else {
-    ASSERT(version == ARMv7);
-    Instr* movw_ip = Instr::At(pc_ + (0 * Instr::kInstrSize));  // target_lo
-    Instr* movt_ip = Instr::At(pc_ + (1 * Instr::kInstrSize));  // target_hi
-    uint16_t target_lo = movw_ip->MovwField();
-    uint16_t target_hi = movt_ip->MovwField();
-    return (target_hi << 16) | target_lo;
-  }
-}
-
-
-void JumpPattern::SetTargetAddress(uword target_address) const {
-  const ARMVersion version = TargetCPUFeatures::arm_version();
-  if ((version == ARMv5TE) || (version == ARMv6)) {
-    const uint32_t byte0 = (target_address & 0x000000ff);
-    const uint32_t byte1 = (target_address & 0x0000ff00) >> 8;
-    const uint32_t byte2 = (target_address & 0x00ff0000) >> 16;
-    const uint32_t byte3 = (target_address & 0xff000000) >> 24;
-
-    const uword mov_ip = 0xe3a0c400 | byte3;  // mov ip, (byte3 rot 4)
-    const uword or1_ip = 0xe38cc800 | byte2;  // orr ip, ip, (byte2 rot 8)
-    const uword or2_ip = 0xe38ccc00 | byte1;  // orr ip, ip, (byte1 rot 12)
-    const uword or3_ip = 0xe38cc000 | byte0;  // orr ip, ip, byte0
-
-    *reinterpret_cast<uword*>(pc_ + (0 * Instr::kInstrSize)) = mov_ip;
-    *reinterpret_cast<uword*>(pc_ + (1 * Instr::kInstrSize)) = or1_ip;
-    *reinterpret_cast<uword*>(pc_ + (2 * Instr::kInstrSize)) = or2_ip;
-    *reinterpret_cast<uword*>(pc_ + (3 * Instr::kInstrSize)) = or3_ip;
-    CPU::FlushICache(pc_, 4 * Instr::kInstrSize);
-  } else {
-    ASSERT(version == ARMv7);
-    const uint16_t target_lo = target_address & 0xffff;
-    const uint16_t target_hi = target_address >> 16;
-
-    const uword movw_ip =
-        0xe300c000 | ((target_lo >> 12) << 16) | (target_lo & 0xfff);
-    const uword movt_ip =
-        0xe340c000 | ((target_hi >> 12) << 16) | (target_hi & 0xfff);
-
-    *reinterpret_cast<uword*>(pc_ + (0 * Instr::kInstrSize)) = movw_ip;
-    *reinterpret_cast<uword*>(pc_ + (1 * Instr::kInstrSize)) = movt_ip;
-    CPU::FlushICache(pc_, 2 * Instr::kInstrSize);
-  }
-}
-
 
 ReturnPattern::ReturnPattern(uword pc)
     : pc_(pc) {
 }
 
 
 bool ReturnPattern::IsValid() const {
   Instr* bx_lr = Instr::At(pc_);
   const int32_t B4 = 1 << 4;
   const int32_t B21 = 1 << 21;
   const int32_t B24 = 1 << 24;
   int32_t instruction = (static_cast<int32_t>(AL) << kConditionShift) |
                          B24 | B21 | (0xfff << 8) | B4 |
                         (static_cast<int32_t>(LR) << kRmShift);
   const ARMVersion version = TargetCPUFeatures::arm_version();
   if ((version == ARMv5TE) || (version == ARMv6)) {
     return bx_lr->InstructionBits() == instruction;
   } else {
     ASSERT(version == ARMv7);
     return bx_lr->InstructionBits() == instruction;
   }
   return false;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM