Embedded constant pools.

src/arm/assembler-arm.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 216 matching lines @@
 // -----------------------------------------------------------------------------
 // Implementation of RelocInfo
 
 // static
 const int RelocInfo::kApplyMask = 0;
 
 
 bool RelocInfo::IsCodedSpecially() {
   // The deserializer needs to know whether a pointer is specially coded.  Being
   // specially coded on ARM means that it is a movw/movt instruction, or is an
-  // out of line constant pool entry.  These only occur if
-  // FLAG_enable_ool_constant_pool is true.
-  return FLAG_enable_ool_constant_pool;
+  // embedded constant pool entry.  These only occur if
+  // FLAG_enable_embedded_constant_pool is true.
+  return FLAG_enable_embedded_constant_pool;
 }
 
 
 bool RelocInfo::IsInConstantPool() {
   return Assembler::is_constant_pool_load(pc_);
 }
 
 
 // -----------------------------------------------------------------------------
 // Implementation of Operand and MemOperand
@@ skipping 192 matching lines @@
 const Instr kLdrRegFpNegOffsetPattern =
     al | B26 | L | NegOffset | kRegister_fp_Code * B16;
 const Instr kStrRegFpNegOffsetPattern =
     al | B26 | NegOffset | kRegister_fp_Code * B16;
 const Instr kLdrStrInstrTypeMask = 0xffff0000;
 
 
 Assembler::Assembler(Isolate* isolate, void* buffer, int buffer_size)
     : AssemblerBase(isolate, buffer, buffer_size),
       recorded_ast_id_(TypeFeedbackId::None()),
-      constant_pool_builder_(),
+      constant_pool_builder_(12, 10),

[rmcilroy, 2015/05/20 14:32:10]

make the '12' and '10'  constants defined in constants-arm.h

[MTBrandyberry, 2015/05/20 22:28:21]

Done.

       positions_recorder_(this) {
   reloc_info_writer.Reposition(buffer_ + buffer_size_, pc_);
-  num_pending_32_bit_reloc_info_ = 0;
-  num_pending_64_bit_reloc_info_ = 0;
+  num_pending_32_bit_constants_ = 0;
+  num_pending_64_bit_constants_ = 0;
   next_buffer_check_ = 0;
   const_pool_blocked_nesting_ = 0;
   no_const_pool_before_ = 0;
   first_const_pool_32_use_ = -1;
   first_const_pool_64_use_ = -1;
   last_bound_pos_ = 0;
   ClearRecordedAstId();
 }
 
 
 Assembler::~Assembler() {
   DCHECK(const_pool_blocked_nesting_ == 0);
 }
 
 
 void Assembler::GetCode(CodeDesc* desc) {
   reloc_info_writer.Finish();
-  if (!FLAG_enable_ool_constant_pool) {
-    // Emit constant pool if necessary.
+
+  // Emit constant pool if necessary.
+  int offset = 0;
+  if (FLAG_enable_embedded_constant_pool) {
+    offset = EmitConstantPool();
+  } else {
     CheckConstPool(true, false);
-    DCHECK(num_pending_32_bit_reloc_info_ == 0);
-    DCHECK(num_pending_64_bit_reloc_info_ == 0);
+    DCHECK(num_pending_32_bit_constants_ == 0);
+    DCHECK(num_pending_64_bit_constants_ == 0);
   }
   // Set up code descriptor.
   desc->buffer = buffer_;
   desc->buffer_size = buffer_size_;
   desc->instr_size = pc_offset();
   desc->reloc_size = (buffer_ + buffer_size_) - reloc_info_writer.pos();
+  desc->constant_pool_size = (offset ? desc->instr_size - offset : 0);
   desc->origin = this;
 }
 
 
 void Assembler::Align(int m) {
   DCHECK(m >= 4 && base::bits::IsPowerOfTwo32(m));
   while ((pc_offset() & (m - 1)) != 0) {
     nop();
   }
 }
@@ skipping 121 matching lines @@
 
 
 Register Assembler::GetRm(Instr instr) {
   Register reg;
   reg.code_ = Instruction::RmValue(instr);
   return reg;
 }
 
 
 Instr Assembler::GetConsantPoolLoadPattern() {
-  if (FLAG_enable_ool_constant_pool) {
+  if (FLAG_enable_embedded_constant_pool) {
     return kLdrPpImmedPattern;
   } else {
     return kLdrPCImmedPattern;
   }
 }
 
 
 Instr Assembler::GetConsantPoolLoadMask() {
-  if (FLAG_enable_ool_constant_pool) {
+  if (FLAG_enable_embedded_constant_pool) {
     return kLdrPpImmedMask;
   } else {
     return kLdrPCImmedMask;
   }
 }
 
 
 bool Assembler::IsPush(Instr instr) {
   return ((instr & ~kRdMask) == kPushRegPattern);
 }
@@ skipping 391 matching lines @@
     return assembler->serializer_enabled();
   } else if (RelocInfo::IsNone(rmode_)) {
     return false;
   }
   return true;
 }
 
 
 static bool use_mov_immediate_load(const Operand& x,
                                    const Assembler* assembler) {
-  if (FLAG_enable_ool_constant_pool && assembler != NULL &&
-      !assembler->is_ool_constant_pool_available()) {
+  if (FLAG_enable_embedded_constant_pool && assembler != NULL &&
+      !assembler->is_constant_pool_available()) {
     return true;
   } else if (CpuFeatures::IsSupported(MOVW_MOVT_IMMEDIATE_LOADS) &&
              (assembler == NULL || !assembler->predictable_code_size())) {
     // Prefer movw / movt to constant pool if it is more efficient on the CPU.
     return true;
   } else if (x.must_output_reloc_info(assembler)) {
     // Prefer constant pool if data is likely to be patched.
     return false;
   } else {
     // Otherwise, use immediate load if movw / movt is available.
     return CpuFeatures::IsSupported(ARMv7);
   }
 }
 
 
 int Operand::instructions_required(const Assembler* assembler,
                                    Instr instr) const {
   if (rm_.is_valid()) return 1;
   uint32_t dummy1, dummy2;
   if (must_output_reloc_info(assembler) ||
       !fits_shifter(imm32_, &dummy1, &dummy2, &instr)) {
     // The immediate operand cannot be encoded as a shifter operand, or use of
     // constant pool is required.  First account for the instructions required
     // for the constant pool or immediate load
     int instructions;
     if (use_mov_immediate_load(*this, assembler)) {
       // A movw / movt or mov / orr immediate load.
       instructions = CpuFeatures::IsSupported(ARMv7) ? 2 : 4;
-    } else if (assembler != NULL && assembler->use_extended_constant_pool()) {
+    } else if (assembler != NULL && assembler->ConstantPoolOverflow()) {
       // An extended constant pool load.

[rmcilroy, 2015/05/20 14:32:10]

update comment.

[MTBrandyberry, 2015/05/20 22:28:21]

Done.

       instructions = CpuFeatures::IsSupported(ARMv7) ? 3 : 5;
     } else {
       // A small constant pool load.
       instructions = 1;
     }
 
     if ((instr & ~kCondMask) != 13 * B21) {  // mov, S not set
       // For a mov or mvn instruction which doesn't set the condition
       // code, the constant pool or immediate load is enough, otherwise we need
       // to account for the actual instruction being requested.
       instructions += 1;
     }
     return instructions;
   } else {
     // No use of constant pool and the immediate operand can be encoded as a
     // shifter operand.
     return 1;
   }
 }
 
 
 void Assembler::move_32_bit_immediate(Register rd,
                                       const Operand& x,
                                       Condition cond) {
-  RelocInfo rinfo(pc_, x.rmode_, x.imm32_, NULL);
   uint32_t imm32 = static_cast<uint32_t>(x.imm32_);
   if (x.must_output_reloc_info(this)) {
-    RecordRelocInfo(rinfo);
+    RecordRelocInfo(x.rmode_);
   }
 
   if (use_mov_immediate_load(x, this)) {
     Register target = rd.code() == pc.code() ? ip : rd;
     if (CpuFeatures::IsSupported(ARMv7)) {
-      if (!FLAG_enable_ool_constant_pool && x.must_output_reloc_info(this)) {
+      if (!FLAG_enable_embedded_constant_pool &&
+          x.must_output_reloc_info(this)) {
         // Make sure the movw/movt doesn't get separated.
         BlockConstPoolFor(2);
       }
       movw(target, imm32 & 0xffff, cond);
       movt(target, imm32 >> 16, cond);
     } else {
-      DCHECK(FLAG_enable_ool_constant_pool);
+      DCHECK(FLAG_enable_embedded_constant_pool);
       mov(target, Operand(imm32 & kImm8Mask), LeaveCC, cond);
       orr(target, target, Operand(imm32 & (kImm8Mask << 8)), LeaveCC, cond);
       orr(target, target, Operand(imm32 & (kImm8Mask << 16)), LeaveCC, cond);
       orr(target, target, Operand(imm32 & (kImm8Mask << 24)), LeaveCC, cond);
     }
     if (target.code() != rd.code()) {
       mov(rd, target, LeaveCC, cond);
     }
   } else {
-    DCHECK(!FLAG_enable_ool_constant_pool || is_ool_constant_pool_available());
-    ConstantPoolArray::LayoutSection section = ConstantPoolAddEntry(rinfo);
-    if (section == ConstantPoolArray::EXTENDED_SECTION) {
-      DCHECK(FLAG_enable_ool_constant_pool);
+    DCHECK(!FLAG_enable_embedded_constant_pool || is_constant_pool_available());
+    ConstantPoolEntry::Access access =
+        ConstantPoolAddEntry(pc_offset(), x.rmode_, x.imm32_);
+    if (access == ConstantPoolEntry::OVERFLOWED) {
+      DCHECK(FLAG_enable_embedded_constant_pool);
       Register target = rd.code() == pc.code() ? ip : rd;
       // Emit instructions to load constant pool offset.
       if (CpuFeatures::IsSupported(ARMv7)) {
         movw(target, 0, cond);
         movt(target, 0, cond);
       } else {
         mov(target, Operand(0), LeaveCC, cond);
         orr(target, target, Operand(0), LeaveCC, cond);
         orr(target, target, Operand(0), LeaveCC, cond);
         orr(target, target, Operand(0), LeaveCC, cond);
       }
       // Load from constant pool at offset.
       ldr(rd, MemOperand(pp, target), cond);
     } else {
-      DCHECK(section == ConstantPoolArray::SMALL_SECTION);
-      ldr(rd, MemOperand(FLAG_enable_ool_constant_pool ? pp : pc, 0), cond);
+      DCHECK(access == ConstantPoolEntry::REGULAR);
+      ldr(rd, MemOperand(FLAG_enable_embedded_constant_pool ? pp : pc, 0),
+          cond);
     }
   }
 }
 
 
 void Assembler::addrmod1(Instr instr,
                          Register rn,
                          Register rd,
                          const Operand& x) {
   CheckBuffer();
@@ skipping 1388 matching lines @@
   if (CpuFeatures::IsSupported(VFP3) && FitsVMOVDoubleImmediate(imm, &enc)) {
     // The double can be encoded in the instruction.
     //
     // Dd = immediate
     // Instruction details available in ARM DDI 0406C.b, A8-936.
     // cond(31-28) | 11101(27-23) | D(22) | 11(21-20) | imm4H(19-16) |
     // Vd(15-12) | 101(11-9) | sz=1(8) | imm4L(3-0)
     int vd, d;
     dst.split_code(&vd, &d);
     emit(al | 0x1D*B23 | d*B22 | 0x3*B20 | vd*B12 | 0x5*B9 | B8 | enc);
-  } else if (FLAG_enable_vldr_imm && is_ool_constant_pool_available()) {
+  } else if (FLAG_enable_vldr_imm && is_constant_pool_available()) {
     // TODO(jfb) Temporarily turned off until we have constant blinding or
     //           some equivalent mitigation: an attacker can otherwise control
     //           generated data which also happens to be executable, a Very Bad
     //           Thing indeed.
     //           Blinding gets tricky because we don't have xor, we probably
     //           need to add/subtract without losing precision, which requires a
     //           cookie value that Lithium is probably better positioned to
     //           choose.
     //           We could also add a few peepholes here like detecting 0.0 and
     //           -0.0 and doing a vmov from the sequestered d14, forcing denorms
     //           to zero (we set flush-to-zero), and normalizing NaN values.
     //           We could also detect redundant values.
     //           The code could also randomize the order of values, though
     //           that's tricky because vldr has a limited reach. Furthermore
     //           it breaks load locality.
-    RelocInfo rinfo(pc_, imm);
-    ConstantPoolArray::LayoutSection section = ConstantPoolAddEntry(rinfo);
-    if (section == ConstantPoolArray::EXTENDED_SECTION) {
-      DCHECK(FLAG_enable_ool_constant_pool);
+    ConstantPoolEntry::Access access = ConstantPoolAddEntry(pc_offset(), imm);
+    if (access == ConstantPoolEntry::OVERFLOWED) {
+      DCHECK(FLAG_enable_embedded_constant_pool);
       // Emit instructions to load constant pool offset.
       movw(ip, 0);
       movt(ip, 0);
       // Load from constant pool at offset.
       vldr(dst, MemOperand(pp, ip));
     } else {
-      DCHECK(section == ConstantPoolArray::SMALL_SECTION);
-      vldr(dst, MemOperand(FLAG_enable_ool_constant_pool ? pp : pc, 0));
+      DCHECK(access == ConstantPoolEntry::REGULAR);
+      vldr(dst, MemOperand(FLAG_enable_embedded_constant_pool ? pp : pc, 0));
     }
   } else {
     // Synthesise the double from ARM immediates.
     uint32_t lo, hi;
     DoubleAsTwoUInt32(imm, &lo, &hi);
 
     if (lo == hi) {
       // Move the low and high parts of the double to a D register in one
       // instruction.
       mov(ip, Operand(lo));
@@ skipping 953 matching lines @@
   DeleteArray(buffer_);
   buffer_ = desc.buffer;
   buffer_size_ = desc.buffer_size;
   pc_ += pc_delta;
   reloc_info_writer.Reposition(reloc_info_writer.pos() + rc_delta,
                                reloc_info_writer.last_pc() + pc_delta);
 
   // None of our relocation types are pc relative pointing outside the code
   // buffer nor pc absolute pointing inside the code buffer, so there is no need
   // to relocate any emitted relocation entries.
-
-  // Relocate pending relocation entries.
-  for (int i = 0; i < num_pending_32_bit_reloc_info_; i++) {
-    RelocInfo& rinfo = pending_32_bit_reloc_info_[i];
-    DCHECK(rinfo.rmode() != RelocInfo::COMMENT &&
-           rinfo.rmode() != RelocInfo::POSITION);
-    if (rinfo.rmode() != RelocInfo::JS_RETURN) {
-      rinfo.set_pc(rinfo.pc() + pc_delta);
-    }
-  }
-  for (int i = 0; i < num_pending_64_bit_reloc_info_; i++) {
-    RelocInfo& rinfo = pending_64_bit_reloc_info_[i];
-    DCHECK(rinfo.rmode() == RelocInfo::NONE64);
-    rinfo.set_pc(rinfo.pc() + pc_delta);
-  }
-  constant_pool_builder_.Relocate(pc_delta);
 }
 
 
 void Assembler::db(uint8_t data) {
   // No relocation info should be pending while using db. db is used
   // to write pure data with no pointers and the constant pool should
   // be emitted before using db.
-  DCHECK(num_pending_32_bit_reloc_info_ == 0);
-  DCHECK(num_pending_64_bit_reloc_info_ == 0);
+  DCHECK(num_pending_32_bit_constants_ == 0);
+  DCHECK(num_pending_64_bit_constants_ == 0);
   CheckBuffer();
   *reinterpret_cast<uint8_t*>(pc_) = data;
   pc_ += sizeof(uint8_t);
 }
 
 
 void Assembler::dd(uint32_t data) {
   // No relocation info should be pending while using dd. dd is used
   // to write pure data with no pointers and the constant pool should
   // be emitted before using dd.
-  DCHECK(num_pending_32_bit_reloc_info_ == 0);
-  DCHECK(num_pending_64_bit_reloc_info_ == 0);
+  DCHECK(num_pending_32_bit_constants_ == 0);
+  DCHECK(num_pending_64_bit_constants_ == 0);
   CheckBuffer();
   *reinterpret_cast<uint32_t*>(pc_) = data;
   pc_ += sizeof(uint32_t);
 }
 
 
+void Assembler::dq(uint64_t value) {
+  CheckBuffer();

[rmcilroy, 2015/05/20 14:32:10]

Please add the num_pending_xx_bit_constants_ == 0 DCHECKs here too.

[MTBrandyberry, 2015/05/20 22:28:21]

Done.

+  *reinterpret_cast<uint64_t*>(pc_) = value;
+  pc_ += sizeof(uint64_t);
+}
+
+
 void Assembler::emit_code_stub_address(Code* stub) {
   CheckBuffer();
   *reinterpret_cast<uint32_t*>(pc_) =
       reinterpret_cast<uint32_t>(stub->instruction_start());
   pc_ += sizeof(uint32_t);
 }
 
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
+  if (RelocInfo::IsNone(rmode) ||
+      // Don't record external references unless the heap will be serialized.
+      (rmode == RelocInfo::EXTERNAL_REFERENCE && !serializer_enabled() &&
+       !emit_debug_code())) {
+    return;
+  }
+  DCHECK(buffer_space() >= kMaxRelocSize);  // too late to grow buffer here
+  if (rmode == RelocInfo::CODE_TARGET_WITH_ID) {
+    data = RecordedAstId().ToInt();
+    ClearRecordedAstId();
+  }
   RelocInfo rinfo(pc_, rmode, data, NULL);
-  RecordRelocInfo(rinfo);
+  reloc_info_writer.Write(&rinfo);
 }
 
 
-void Assembler::RecordRelocInfo(const RelocInfo& rinfo) {
-  if (!RelocInfo::IsNone(rinfo.rmode())) {
-    // Don't record external references unless the heap will be serialized.
-    if (rinfo.rmode() == RelocInfo::EXTERNAL_REFERENCE &&
-        !serializer_enabled() && !emit_debug_code()) {
-      return;
+ConstantPoolEntry::Access Assembler::ConstantPoolAddEntry(int position,
+                                                          RelocInfo::Mode rmode,
+                                                          intptr_t value) {
+  DCHECK(rmode != RelocInfo::COMMENT && rmode != RelocInfo::POSITION &&
+         rmode != RelocInfo::STATEMENT_POSITION &&
+         rmode != RelocInfo::CONST_POOL && rmode != RelocInfo::NONE64);
+  bool sharing_ok = RelocInfo::IsNone(rmode) ||
+                    !(serializer_enabled() || rmode < RelocInfo::CELL);
+  if (FLAG_enable_embedded_constant_pool) {
+    return constant_pool_builder_.AddEntry(position, value, sharing_ok);
+  } else {
+    DCHECK(num_pending_32_bit_constants_ < kMaxNumPending32Constants);
+    if (num_pending_32_bit_constants_ == 0) {
+      first_const_pool_32_use_ = position;
     }
-    DCHECK(buffer_space() >= kMaxRelocSize);  // too late to grow buffer here
-    if (rinfo.rmode() == RelocInfo::CODE_TARGET_WITH_ID) {
-      RelocInfo reloc_info_with_ast_id(rinfo.pc(),
-                                       rinfo.rmode(),
-                                       RecordedAstId().ToInt(),
-                                       NULL);
-      ClearRecordedAstId();
-      reloc_info_writer.Write(&reloc_info_with_ast_id);
-    } else {
-      reloc_info_writer.Write(&rinfo);
-    }
+    ConstantPoolEntry entry(position, value, sharing_ok);
+    pending_32_bit_constants_[num_pending_32_bit_constants_++] = entry;
+
+    // Make sure the constant pool is not emitted in place of the next
+    // instruction for which we just recorded relocation info.
+    BlockConstPoolFor(1);
+    return ConstantPoolEntry::REGULAR;
   }
 }
 
 
-ConstantPoolArray::LayoutSection Assembler::ConstantPoolAddEntry(
-    const RelocInfo& rinfo) {
-  if (FLAG_enable_ool_constant_pool) {
-    return constant_pool_builder_.AddEntry(this, rinfo);
+ConstantPoolEntry::Access Assembler::ConstantPoolAddEntry(int position,
+                                                          double value) {
+  if (FLAG_enable_embedded_constant_pool) {
+    return constant_pool_builder_.AddEntry(position, value);
   } else {
-    if (rinfo.rmode() == RelocInfo::NONE64) {
-      DCHECK(num_pending_64_bit_reloc_info_ < kMaxNumPending64RelocInfo);
-      if (num_pending_64_bit_reloc_info_ == 0) {
-        first_const_pool_64_use_ = pc_offset();
-      }
-      pending_64_bit_reloc_info_[num_pending_64_bit_reloc_info_++] = rinfo;
-    } else {
-      DCHECK(num_pending_32_bit_reloc_info_ < kMaxNumPending32RelocInfo);
-      if (num_pending_32_bit_reloc_info_ == 0) {
-        first_const_pool_32_use_ = pc_offset();
-      }
-      pending_32_bit_reloc_info_[num_pending_32_bit_reloc_info_++] = rinfo;
+    DCHECK(num_pending_64_bit_constants_ < kMaxNumPending64Constants);
+    if (num_pending_64_bit_constants_ == 0) {
+      first_const_pool_64_use_ = position;
     }
+    ConstantPoolEntry entry(position, value);
+    pending_64_bit_constants_[num_pending_64_bit_constants_++] = entry;
+
     // Make sure the constant pool is not emitted in place of the next
     // instruction for which we just recorded relocation info.
     BlockConstPoolFor(1);
-    return ConstantPoolArray::SMALL_SECTION;
+    return ConstantPoolEntry::REGULAR;
   }
 }
 
 
 void Assembler::BlockConstPoolFor(int instructions) {
-  if (FLAG_enable_ool_constant_pool) {
-    // Should be a no-op if using an out-of-line constant pool.
-    DCHECK(num_pending_32_bit_reloc_info_ == 0);
-    DCHECK(num_pending_64_bit_reloc_info_ == 0);
+  if (FLAG_enable_embedded_constant_pool) {
+    // Should be a no-op if using an embedded constant pool.
+    DCHECK(num_pending_32_bit_constants_ == 0);
+    DCHECK(num_pending_64_bit_constants_ == 0);
     return;
   }
 
   int pc_limit = pc_offset() + instructions * kInstrSize;
   if (no_const_pool_before_ < pc_limit) {
     // Max pool start (if we need a jump and an alignment).
 #ifdef DEBUG
     int start = pc_limit + kInstrSize + 2 * kPointerSize;
-    DCHECK((num_pending_32_bit_reloc_info_ == 0) ||
+    DCHECK((num_pending_32_bit_constants_ == 0) ||
            (start - first_const_pool_32_use_ +
-            num_pending_64_bit_reloc_info_ * kDoubleSize < kMaxDistToIntPool));
-    DCHECK((num_pending_64_bit_reloc_info_ == 0) ||
+                num_pending_64_bit_constants_ * kDoubleSize <
+            kMaxDistToIntPool));
+    DCHECK((num_pending_64_bit_constants_ == 0) ||
            (start - first_const_pool_64_use_ < kMaxDistToFPPool));
 #endif
     no_const_pool_before_ = pc_limit;
   }
 
   if (next_buffer_check_ < no_const_pool_before_) {
     next_buffer_check_ = no_const_pool_before_;
   }
 }
 
 
 void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
-  if (FLAG_enable_ool_constant_pool) {
-    // Should be a no-op if using an out-of-line constant pool.
-    DCHECK(num_pending_32_bit_reloc_info_ == 0);
-    DCHECK(num_pending_64_bit_reloc_info_ == 0);
+  if (FLAG_enable_embedded_constant_pool) {
+    // Should be a no-op if using an embedded constant pool.
+    DCHECK(num_pending_32_bit_constants_ == 0);
+    DCHECK(num_pending_64_bit_constants_ == 0);
     return;
   }
 
   // Some short sequence of instruction mustn't be broken up by constant pool
   // emission, such sequences are protected by calls to BlockConstPoolFor and
   // BlockConstPoolScope.
   if (is_const_pool_blocked()) {
     // Something is wrong if emission is forced and blocked at the same time.
     DCHECK(!force_emit);
     return;
   }
 
   // There is nothing to do if there are no pending constant pool entries.
-  if ((num_pending_32_bit_reloc_info_ == 0) &&
-      (num_pending_64_bit_reloc_info_ == 0)) {
+  if ((num_pending_32_bit_constants_ == 0) &&
+      (num_pending_64_bit_constants_ == 0)) {
     // Calculate the offset of the next check.
     next_buffer_check_ = pc_offset() + kCheckPoolInterval;
     return;
   }
 
   // Check that the code buffer is large enough before emitting the constant
   // pool (include the jump over the pool and the constant pool marker and
   // the gap to the relocation information).
   int jump_instr = require_jump ? kInstrSize : 0;
   int size_up_to_marker = jump_instr + kInstrSize;
-  int size_after_marker = num_pending_32_bit_reloc_info_ * kPointerSize;
-  bool has_fp_values = (num_pending_64_bit_reloc_info_ > 0);
+  int size_after_marker = num_pending_32_bit_constants_ * kPointerSize;
+  bool has_fp_values = (num_pending_64_bit_constants_ > 0);
   bool require_64_bit_align = false;
   if (has_fp_values) {
     require_64_bit_align = (((uintptr_t)pc_ + size_up_to_marker) & 0x7);
     if (require_64_bit_align) {
       size_after_marker += kInstrSize;
     }
-    size_after_marker += num_pending_64_bit_reloc_info_ * kDoubleSize;
+    size_after_marker += num_pending_64_bit_constants_ * kDoubleSize;
   }
 
   int size = size_up_to_marker + size_after_marker;
 
   // We emit a constant pool when:
   //  * requested to do so by parameter force_emit (e.g. after each function).
   //  * the distance from the first instruction accessing the constant pool to
   //    any of the constant pool entries will exceed its limit the next
   //    time the pool is checked. This is overly restrictive, but we don't emit
   //    constant pool entries in-order so it's conservatively correct.
   //  * the instruction doesn't require a jump after itself to jump over the
   //    constant pool, and we're getting close to running out of range.
   if (!force_emit) {
     DCHECK((first_const_pool_32_use_ >= 0) || (first_const_pool_64_use_ >= 0));
     bool need_emit = false;
     if (has_fp_values) {
-      int dist64 = pc_offset() +
-                   size -
-                   num_pending_32_bit_reloc_info_ * kPointerSize -
+      int dist64 = pc_offset() + size -
+                   num_pending_32_bit_constants_ * kPointerSize -
                    first_const_pool_64_use_;
       if ((dist64 >= kMaxDistToFPPool - kCheckPoolInterval) ||
           (!require_jump && (dist64 >= kMaxDistToFPPool / 2))) {
         need_emit = true;
       }
     }
     int dist32 =
       pc_offset() + size - first_const_pool_32_use_;
     if ((dist32 >= kMaxDistToIntPool - kCheckPoolInterval) ||
         (!require_jump && (dist32 >= kMaxDistToIntPool / 2))) {
@@ skipping 21 matching lines @@
     // The data size helps disassembly know what to print.
     emit(kConstantPoolMarker |
          EncodeConstantPoolLength(size_after_marker / kPointerSize));
 
     if (require_64_bit_align) {
       emit(kConstantPoolMarker);
     }
 
     // Emit 64-bit constant pool entries first: their range is smaller than
     // 32-bit entries.
-    for (int i = 0; i < num_pending_64_bit_reloc_info_; i++) {
-      RelocInfo& rinfo = pending_64_bit_reloc_info_[i];
+    for (int i = 0; i < num_pending_64_bit_constants_; i++) {
+      ConstantPoolEntry& entry = pending_64_bit_constants_[i];
 
       DCHECK(!((uintptr_t)pc_ & 0x7));  // Check 64-bit alignment.
 
-      Instr instr = instr_at(rinfo.pc());
+      Instr instr = instr_at(entry.position());
       // Instruction to patch must be 'vldr rd, [pc, #offset]' with offset == 0.
       DCHECK((IsVldrDPcImmediateOffset(instr) &&
               GetVldrDRegisterImmediateOffset(instr) == 0));
 
-      int delta = pc_ - rinfo.pc() - kPcLoadDelta;
+      int delta = pc_offset() - entry.position() - kPcLoadDelta;
       DCHECK(is_uint10(delta));
 
       bool found = false;
-      uint64_t value = rinfo.raw_data64();
+      uint64_t value = entry.value64();
       for (int j = 0; j < i; j++) {
-        RelocInfo& rinfo2 = pending_64_bit_reloc_info_[j];
-        if (value == rinfo2.raw_data64()) {
+        ConstantPoolEntry& entry2 = pending_64_bit_constants_[j];
+        if (value == entry2.value64()) {
           found = true;
-          DCHECK(rinfo2.rmode() == RelocInfo::NONE64);
-          Instr instr2 = instr_at(rinfo2.pc());
+          Instr instr2 = instr_at(entry2.position());
           DCHECK(IsVldrDPcImmediateOffset(instr2));
           delta = GetVldrDRegisterImmediateOffset(instr2);
-          delta += rinfo2.pc() - rinfo.pc();
+          delta += entry2.position() - entry.position();
           break;
         }
       }
 
-      instr_at_put(rinfo.pc(), SetVldrDRegisterImmediateOffset(instr, delta));
+      instr_at_put(entry.position(),
+                   SetVldrDRegisterImmediateOffset(instr, delta));
 
       if (!found) {
-        uint64_t uint_data = rinfo.raw_data64();
-        emit(uint_data & 0xFFFFFFFF);
-        emit(uint_data >> 32);
+        dq(entry.value64());
       }
     }
 
     // Emit 32-bit constant pool entries.
-    for (int i = 0; i < num_pending_32_bit_reloc_info_; i++) {
-      RelocInfo& rinfo = pending_32_bit_reloc_info_[i];
-      DCHECK(rinfo.rmode() != RelocInfo::COMMENT &&
-             rinfo.rmode() != RelocInfo::POSITION &&
-             rinfo.rmode() != RelocInfo::STATEMENT_POSITION &&
-             rinfo.rmode() != RelocInfo::CONST_POOL &&
-             rinfo.rmode() != RelocInfo::NONE64);
-
-      Instr instr = instr_at(rinfo.pc());
+    for (int i = 0; i < num_pending_32_bit_constants_; i++) {
+      ConstantPoolEntry& entry = pending_32_bit_constants_[i];
+      Instr instr = instr_at(entry.position());
 
       // 64-bit loads shouldn't get here.
       DCHECK(!IsVldrDPcImmediateOffset(instr));
 
       if (IsLdrPcImmediateOffset(instr) &&
           GetLdrRegisterImmediateOffset(instr) == 0) {
-        int delta = pc_ - rinfo.pc() - kPcLoadDelta;
+        int delta = pc_offset() - entry.position() - kPcLoadDelta;
         DCHECK(is_uint12(delta));
         // 0 is the smallest delta:
         //   ldr rd, [pc, #0]
         //   constant pool marker
         //   data
 
         bool found = false;
-        if (!serializer_enabled() && rinfo.rmode() >= RelocInfo::CELL) {
+        if (entry.sharing_ok()) {
           for (int j = 0; j < i; j++) {
-            RelocInfo& rinfo2 = pending_32_bit_reloc_info_[j];
+            ConstantPoolEntry& entry2 = pending_32_bit_constants_[j];
 
-            if ((rinfo2.data() == rinfo.data()) &&
-                (rinfo2.rmode() == rinfo.rmode())) {
-              Instr instr2 = instr_at(rinfo2.pc());
+            if (entry2.value() == entry.value()) {
+              Instr instr2 = instr_at(entry2.position());
               if (IsLdrPcImmediateOffset(instr2)) {
                 delta = GetLdrRegisterImmediateOffset(instr2);
-                delta += rinfo2.pc() - rinfo.pc();
+                delta += entry2.position() - entry.position();
                 found = true;
                 break;
               }
             }
           }
         }
 
-        instr_at_put(rinfo.pc(), SetLdrRegisterImmediateOffset(instr, delta));
+        instr_at_put(entry.position(),
+                     SetLdrRegisterImmediateOffset(instr, delta));
 
         if (!found) {
-          emit(rinfo.data());
+          dp(entry.value());
         }
       } else {
         DCHECK(IsMovW(instr));
       }
     }
 
-    num_pending_32_bit_reloc_info_ = 0;
-    num_pending_64_bit_reloc_info_ = 0;
+    num_pending_32_bit_constants_ = 0;
+    num_pending_64_bit_constants_ = 0;
     first_const_pool_32_use_ = -1;
     first_const_pool_64_use_ = -1;
 
     RecordComment("]");
 
     if (after_pool.is_linked()) {
       bind(&after_pool);
     }
   }
 
   // Since a constant pool was just emitted, move the check offset forward by
   // the standard interval.
   next_buffer_check_ = pc_offset() + kCheckPoolInterval;
 }
 
 
-Handle<ConstantPoolArray> Assembler::NewConstantPool(Isolate* isolate) {
-  if (!FLAG_enable_ool_constant_pool) {
-    return isolate->factory()->empty_constant_pool_array();
-  }
-  return constant_pool_builder_.New(isolate);
-}
+void Assembler::SetConstantPoolOffset(int pos, int offset,

[rmcilroy, 2015/05/20 14:32:10]

I think this would be clearer as something like
PatchConstantPoolAccessInstruction.
Also, rename pos -> pc_offset

[MTBrandyberry, 2015/05/20 22:28:21]

Done.

+                                      ConstantPoolEntry::Access access,
+                                      ConstantPoolEntry::Type type) {
+  DCHECK(FLAG_enable_embedded_constant_pool);
+  Address pc = buffer_ + pos;
 
-
-void Assembler::PopulateConstantPool(ConstantPoolArray* constant_pool) {
-  constant_pool_builder_.Populate(this, constant_pool);
-}
-
-
-ConstantPoolBuilder::ConstantPoolBuilder()
-    : entries_(), current_section_(ConstantPoolArray::SMALL_SECTION) {}
-
-
-bool ConstantPoolBuilder::IsEmpty() {
-  return entries_.size() == 0;
-}
-
-
-ConstantPoolArray::Type ConstantPoolBuilder::GetConstantPoolType(
-    RelocInfo::Mode rmode) {
-  if (rmode == RelocInfo::NONE64) {
-    return ConstantPoolArray::INT64;
-  } else if (!RelocInfo::IsGCRelocMode(rmode)) {
-    return ConstantPoolArray::INT32;
-  } else if (RelocInfo::IsCodeTarget(rmode)) {
-    return ConstantPoolArray::CODE_PTR;
+  // Patch vldr/ldr instruction with correct offset.
+  Instr instr = instr_at(pc);
+  if (access == ConstantPoolEntry::OVERFLOWED) {
+    if (CpuFeatures::IsSupported(ARMv7)) {
+      // Instructions to patch must be 'movw rd, [#0]' and 'movt rd, [#0].
+      Instr next_instr = instr_at(pc + kInstrSize);
+      DCHECK((IsMovW(instr) && Instruction::ImmedMovwMovtValue(instr) == 0));
+      DCHECK((IsMovT(next_instr) &&
+              Instruction::ImmedMovwMovtValue(next_instr) == 0));
+      instr_at_put(pc, PatchMovwImmediate(instr, offset & 0xffff));
+      instr_at_put(pc + kInstrSize,
+                   PatchMovwImmediate(next_instr, offset >> 16));
+    } else {
+      // Instructions to patch must be 'mov rd, [#0]' and 'orr rd, rd, [#0].
+      Instr instr_2 = instr_at(pc + kInstrSize);
+      Instr instr_3 = instr_at(pc + 2 * kInstrSize);
+      Instr instr_4 = instr_at(pc + 3 * kInstrSize);
+      DCHECK((IsMovImmed(instr) && Instruction::Immed8Value(instr) == 0));
+      DCHECK((IsOrrImmed(instr_2) && Instruction::Immed8Value(instr_2) == 0) &&
+             GetRn(instr_2).is(GetRd(instr_2)));
+      DCHECK((IsOrrImmed(instr_3) && Instruction::Immed8Value(instr_3) == 0) &&
+             GetRn(instr_3).is(GetRd(instr_3)));
+      DCHECK((IsOrrImmed(instr_4) && Instruction::Immed8Value(instr_4) == 0) &&
+             GetRn(instr_4).is(GetRd(instr_4)));
+      instr_at_put(pc, PatchShiftImm(instr, (offset & kImm8Mask)));
+      instr_at_put(pc + kInstrSize,
+                   PatchShiftImm(instr_2, (offset & (kImm8Mask << 8))));
+      instr_at_put(pc + 2 * kInstrSize,
+                   PatchShiftImm(instr_3, (offset & (kImm8Mask << 16))));
+      instr_at_put(pc + 3 * kInstrSize,
+                   PatchShiftImm(instr_4, (offset & (kImm8Mask << 24))));
+    }
+  } else if (type == ConstantPoolEntry::DOUBLE) {
+    // Instruction to patch must be 'vldr rd, [pp, #0]'.
+    DCHECK((IsVldrDPpImmediateOffset(instr) &&
+            GetVldrDRegisterImmediateOffset(instr) == 0));
+    DCHECK(is_uint10(offset));
+    instr_at_put(pc, SetVldrDRegisterImmediateOffset(instr, offset));
   } else {
-    DCHECK(RelocInfo::IsGCRelocMode(rmode) && !RelocInfo::IsCodeTarget(rmode));
-    return ConstantPoolArray::HEAP_PTR;
+    // Instruction to patch must be 'ldr rd, [pp, #0]'.
+    DCHECK((IsLdrPpImmediateOffset(instr) &&
+            GetLdrRegisterImmediateOffset(instr) == 0));
+    DCHECK(is_uint12(offset));
+    instr_at_put(pc, SetLdrRegisterImmediateOffset(instr, offset));
   }
 }
 
-
-ConstantPoolArray::LayoutSection ConstantPoolBuilder::AddEntry(
-    Assembler* assm, const RelocInfo& rinfo) {
-  RelocInfo::Mode rmode = rinfo.rmode();
-  DCHECK(rmode != RelocInfo::COMMENT &&
-         rmode != RelocInfo::POSITION &&
-         rmode != RelocInfo::STATEMENT_POSITION &&
-         rmode != RelocInfo::CONST_POOL);
-
-  // Try to merge entries which won't be patched.
-  int merged_index = -1;
-  ConstantPoolArray::LayoutSection entry_section = current_section_;
-  if (RelocInfo::IsNone(rmode) ||
-      (!assm->serializer_enabled() && (rmode >= RelocInfo::CELL))) {
-    size_t i;
-    std::vector<ConstantPoolEntry>::const_iterator it;
-    for (it = entries_.begin(), i = 0; it != entries_.end(); it++, i++) {
-      if (RelocInfo::IsEqual(rinfo, it->rinfo_)) {
-        // Merge with found entry.
-        merged_index = i;
-        entry_section = entries_[i].section_;
-        break;
-      }
-    }
-  }
-  DCHECK(entry_section <= current_section_);
-  entries_.push_back(ConstantPoolEntry(rinfo, entry_section, merged_index));
-
-  if (merged_index == -1) {
-    // Not merged, so update the appropriate count.
-    number_of_entries_[entry_section].increment(GetConstantPoolType(rmode));
-  }
-
-  // Check if we still have room for another entry in the small section
-  // given Arm's ldr and vldr immediate offset range.
-  if (current_section_ == ConstantPoolArray::SMALL_SECTION &&
-      !(is_uint12(ConstantPoolArray::SizeFor(*small_entries())) &&
-        is_uint10(ConstantPoolArray::MaxInt64Offset(
-            small_entries()->count_of(ConstantPoolArray::INT64))))) {
-    current_section_ = ConstantPoolArray::EXTENDED_SECTION;
-  }
-  return entry_section;
-}
-
-
-void ConstantPoolBuilder::Relocate(int pc_delta) {
-  for (std::vector<ConstantPoolEntry>::iterator entry = entries_.begin();
-       entry != entries_.end(); entry++) {
-    DCHECK(entry->rinfo_.rmode() != RelocInfo::JS_RETURN);
-    entry->rinfo_.set_pc(entry->rinfo_.pc() + pc_delta);
-  }
-}
-
-
-Handle<ConstantPoolArray> ConstantPoolBuilder::New(Isolate* isolate) {
-  if (IsEmpty()) {
-    return isolate->factory()->empty_constant_pool_array();
-  } else if (extended_entries()->is_empty()) {
-    return isolate->factory()->NewConstantPoolArray(*small_entries());
-  } else {
-    DCHECK(current_section_ == ConstantPoolArray::EXTENDED_SECTION);
-    return isolate->factory()->NewExtendedConstantPoolArray(
-        *small_entries(), *extended_entries());
-  }
-}
-
-
-void ConstantPoolBuilder::Populate(Assembler* assm,
-                                   ConstantPoolArray* constant_pool) {
-  DCHECK_EQ(extended_entries()->is_empty(),
-            !constant_pool->is_extended_layout());
-  DCHECK(small_entries()->equals(ConstantPoolArray::NumberOfEntries(
-      constant_pool, ConstantPoolArray::SMALL_SECTION)));
-  if (constant_pool->is_extended_layout()) {
-    DCHECK(extended_entries()->equals(ConstantPoolArray::NumberOfEntries(
-        constant_pool, ConstantPoolArray::EXTENDED_SECTION)));
-  }
-
-  // Set up initial offsets.
-  int offsets[ConstantPoolArray::NUMBER_OF_LAYOUT_SECTIONS]
-             [ConstantPoolArray::NUMBER_OF_TYPES];
-  for (int section = 0; section <= constant_pool->final_section(); section++) {
-    int section_start = (section == ConstantPoolArray::EXTENDED_SECTION)
-                            ? small_entries()->total_count()
-                            : 0;
-    for (int i = 0; i < ConstantPoolArray::NUMBER_OF_TYPES; i++) {
-      ConstantPoolArray::Type type = static_cast<ConstantPoolArray::Type>(i);
-      if (number_of_entries_[section].count_of(type) != 0) {
-        offsets[section][type] = constant_pool->OffsetOfElementAt(
-            number_of_entries_[section].base_of(type) + section_start);
-      }
-    }
-  }
-
-  for (std::vector<ConstantPoolEntry>::iterator entry = entries_.begin();
-       entry != entries_.end(); entry++) {
-    RelocInfo rinfo = entry->rinfo_;
-    RelocInfo::Mode rmode = entry->rinfo_.rmode();
-    ConstantPoolArray::Type type = GetConstantPoolType(rmode);
-
-    // Update constant pool if necessary and get the entry's offset.
-    int offset;
-    if (entry->merged_index_ == -1) {
-      offset = offsets[entry->section_][type];
-      offsets[entry->section_][type] += ConstantPoolArray::entry_size(type);
-      if (type == ConstantPoolArray::INT64) {
-        constant_pool->set_at_offset(offset, rinfo.data64());
-      } else if (type == ConstantPoolArray::INT32) {
-        constant_pool->set_at_offset(offset,
-                                     static_cast<int32_t>(rinfo.data()));
-      } else if (type == ConstantPoolArray::CODE_PTR) {
-        constant_pool->set_at_offset(offset,
-                                     reinterpret_cast<Address>(rinfo.data()));
-      } else {
-        DCHECK(type == ConstantPoolArray::HEAP_PTR);
-        constant_pool->set_at_offset(offset,
-                                     reinterpret_cast<Object*>(rinfo.data()));
-      }
-      offset -= kHeapObjectTag;
-      entry->merged_index_ = offset;  // Stash offset for merged entries.
-    } else {
-      DCHECK(entry->merged_index_ < (entry - entries_.begin()));
-      offset = entries_[entry->merged_index_].merged_index_;
-    }
-
-    // Patch vldr/ldr instruction with correct offset.
-    Instr instr = assm->instr_at(rinfo.pc());
-    if (entry->section_ == ConstantPoolArray::EXTENDED_SECTION) {
-      if (CpuFeatures::IsSupported(ARMv7)) {
-        // Instructions to patch must be 'movw rd, [#0]' and 'movt rd, [#0].
-        Instr next_instr = assm->instr_at(rinfo.pc() + Assembler::kInstrSize);
-        DCHECK((Assembler::IsMovW(instr) &&
-                Instruction::ImmedMovwMovtValue(instr) == 0));
-        DCHECK((Assembler::IsMovT(next_instr) &&
-                Instruction::ImmedMovwMovtValue(next_instr) == 0));
-        assm->instr_at_put(
-            rinfo.pc(), Assembler::PatchMovwImmediate(instr, offset & 0xffff));
-        assm->instr_at_put(
-            rinfo.pc() + Assembler::kInstrSize,
-            Assembler::PatchMovwImmediate(next_instr, offset >> 16));
-      } else {
-        // Instructions to patch must be 'mov rd, [#0]' and 'orr rd, rd, [#0].
-        Instr instr_2 = assm->instr_at(rinfo.pc() + Assembler::kInstrSize);
-        Instr instr_3 = assm->instr_at(rinfo.pc() + 2 * Assembler::kInstrSize);
-        Instr instr_4 = assm->instr_at(rinfo.pc() + 3 * Assembler::kInstrSize);
-        DCHECK((Assembler::IsMovImmed(instr) &&
-                Instruction::Immed8Value(instr) == 0));
-        DCHECK((Assembler::IsOrrImmed(instr_2) &&
-                Instruction::Immed8Value(instr_2) == 0) &&
-               Assembler::GetRn(instr_2).is(Assembler::GetRd(instr_2)));
-        DCHECK((Assembler::IsOrrImmed(instr_3) &&
-                Instruction::Immed8Value(instr_3) == 0) &&
-               Assembler::GetRn(instr_3).is(Assembler::GetRd(instr_3)));
-        DCHECK((Assembler::IsOrrImmed(instr_4) &&
-                Instruction::Immed8Value(instr_4) == 0) &&
-               Assembler::GetRn(instr_4).is(Assembler::GetRd(instr_4)));
-        assm->instr_at_put(
-            rinfo.pc(), Assembler::PatchShiftImm(instr, (offset & kImm8Mask)));
-        assm->instr_at_put(
-            rinfo.pc() + Assembler::kInstrSize,
-            Assembler::PatchShiftImm(instr_2, (offset & (kImm8Mask << 8))));
-        assm->instr_at_put(
-            rinfo.pc() + 2 * Assembler::kInstrSize,
-            Assembler::PatchShiftImm(instr_3, (offset & (kImm8Mask << 16))));
-        assm->instr_at_put(
-            rinfo.pc() + 3 * Assembler::kInstrSize,
-            Assembler::PatchShiftImm(instr_4, (offset & (kImm8Mask << 24))));
-      }
-    } else if (type == ConstantPoolArray::INT64) {
-      // Instruction to patch must be 'vldr rd, [pp, #0]'.
-      DCHECK((Assembler::IsVldrDPpImmediateOffset(instr) &&
-              Assembler::GetVldrDRegisterImmediateOffset(instr) == 0));
-      DCHECK(is_uint10(offset));
-      assm->instr_at_put(rinfo.pc(), Assembler::SetVldrDRegisterImmediateOffset(
-                                         instr, offset));
-    } else {
-      // Instruction to patch must be 'ldr rd, [pp, #0]'.
-      DCHECK((Assembler::IsLdrPpImmediateOffset(instr) &&
-              Assembler::GetLdrRegisterImmediateOffset(instr) == 0));
-      DCHECK(is_uint12(offset));
-      assm->instr_at_put(
-          rinfo.pc(), Assembler::SetLdrRegisterImmediateOffset(instr, offset));
-    }
-  }
-}
-
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM