MIPS64: Assembler support for internal references.

src/mips64/assembler-mips64.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 157 matching lines @@
     ra
   };
   return kRegisters[num];
 }
 
 
 // -----------------------------------------------------------------------------
 // Implementation of RelocInfo.
 
 const int RelocInfo::kApplyMask = RelocInfo::kCodeTargetMask |
-                                  1 << RelocInfo::INTERNAL_REFERENCE;
+                                  1 << RelocInfo::INTERNAL_REFERENCE |
+                                  1 << RelocInfo::INTERNAL_REFERENCE_ENCODED;
 
 
 bool RelocInfo::IsCodedSpecially() {
   // The deserializer needs to know whether a pointer is specially coded.  Being
   // specially coded on MIPS means that it is a lui/ori instruction, and that is
   // always the case inside code objects.
   return true;
 }
 
 
@@ skipping 438 matching lines @@
   DCHECK(IsAddImmediate(instr));
   return ((instr & ~kImm16Mask) | (offset & kImm16Mask));
 }
 
 
 bool Assembler::IsAndImmediate(Instr instr) {
   return GetOpcodeField(instr) == ANDI;
 }
 
 
-int64_t Assembler::target_at(int64_t pos) {
+int64_t Assembler::target_at(int64_t pos, bool is_internal) {
+  if (is_internal) {
+    int64_t* p = reinterpret_cast<int64_t*>(buffer_ + pos);
+    int64_t address = *p;
+    if (address == kEndOfJumpChain) {
+      return kEndOfChain;
+    } else {
+      int64_t instr_address = reinterpret_cast<int64_t>(p);
+      int64_t delta = instr_address - address;
+      DCHECK(pos > delta);
+      return pos - delta;
+    }
+  }
   Instr instr = instr_at(pos);
   if ((instr & ~kImm16Mask) == 0) {
     // Emitted label constant, not part of a branch.
     if (instr == 0) {
        return kEndOfChain;
      } else {
        int32_t imm18 =((instr & static_cast<int32_t>(kImm16Mask)) << 16) >> 14;
        return (imm18 + pos);
      }
   }
@@ skipping 41 matching lines @@
       uint64_t instr_address = reinterpret_cast<int64_t>(buffer_ + pos);
       instr_address &= kImm28Mask;
       int64_t delta = instr_address - imm28;
       DCHECK(pos > delta);
       return pos - delta;
     }
   }
 }
 
 
-void Assembler::target_at_put(int64_t pos, int64_t target_pos) {
+void Assembler::target_at_put(int64_t pos, int64_t target_pos,
+                              bool is_internal) {
+  if (is_internal) {
+    uint64_t imm = reinterpret_cast<uint64_t>(buffer_) + target_pos;
+    *reinterpret_cast<uint64_t*>(buffer_ + pos) = imm;
+    return;
+  }
   Instr instr = instr_at(pos);
   if ((instr & ~kImm16Mask) == 0) {
     DCHECK(target_pos == kEndOfChain || target_pos >= 0);
     // Emitted label constant, not part of a branch.
     // Make label relative to Code* of generated Code object.
     instr_at_put(pos, target_pos + (Code::kHeaderSize - kHeapObjectTag));
     return;
   }
 
   DCHECK(IsBranch(instr) || IsJ(instr) || IsLui(instr));
@@ skipping 49 matching lines @@
     Label l = *L;
     PrintF("unbound label");
     while (l.is_linked()) {
       PrintF("@ %d ", l.pos());
       Instr instr = instr_at(l.pos());
       if ((instr & ~kImm16Mask) == 0) {
         PrintF("value\n");
       } else {
         PrintF("%d\n", instr);
       }
-      next(&l);
+      next(&l, internal_reference_positions_.find(l.pos()) !=
+                   internal_reference_positions_.end());
     }
   } else {
     PrintF("label in inconsistent state (pos = %d)\n", L->pos_);
   }
 }
 
 
 void Assembler::bind_to(Label* L, int pos) {
   DCHECK(0 <= pos && pos <= pc_offset());  // Must have valid binding position.
   int32_t trampoline_pos = kInvalidSlotPos;
+  bool is_internal = false;
   if (L->is_linked() && !trampoline_emitted_) {
     unbound_labels_count_--;
     next_buffer_check_ += kTrampolineSlotsSize;
   }
 
   while (L->is_linked()) {
     int32_t fixup_pos = L->pos();
     int32_t dist = pos - fixup_pos;
-    next(L);  // Call next before overwriting link with target at fixup_pos.
+    is_internal = internal_reference_positions_.find(fixup_pos) !=
+                  internal_reference_positions_.end();
+    next(L, is_internal);  // Call next before overwriting link with target at
+                           // fixup_pos.
     Instr instr = instr_at(fixup_pos);
-    if (IsBranch(instr)) {
+    if (is_internal) {
+      target_at_put(fixup_pos, pos, is_internal);
+    } else if (IsBranch(instr)) {
       if (dist > kMaxBranchOffset) {
         if (trampoline_pos == kInvalidSlotPos) {
           trampoline_pos = get_trampoline_entry(fixup_pos);
           CHECK(trampoline_pos != kInvalidSlotPos);
         }
         DCHECK((trampoline_pos - fixup_pos) <= kMaxBranchOffset);
-        target_at_put(fixup_pos, trampoline_pos);
+        target_at_put(fixup_pos, trampoline_pos, false);
         fixup_pos = trampoline_pos;
         dist = pos - fixup_pos;
       }
-      target_at_put(fixup_pos, pos);
+      target_at_put(fixup_pos, pos, false);
     } else {
       DCHECK(IsJ(instr) || IsLui(instr) || IsEmittedConstant(instr));
-      target_at_put(fixup_pos, pos);
+      target_at_put(fixup_pos, pos, false);
     }
   }
   L->bind_to(pos);
 
   // Keep track of the last bound label so we don't eliminate any instructions
   // before a bound label.
   if (pos > last_bound_pos_)
     last_bound_pos_ = pos;
 }
 
 
 void Assembler::bind(Label* L) {
   DCHECK(!L->is_bound());  // Label can only be bound once.
   bind_to(L, pc_offset());
 }
 
 
-void Assembler::next(Label* L) {
+void Assembler::next(Label* L, bool is_internal) {
   DCHECK(L->is_linked());
-  int link = target_at(L->pos());
+  int link = target_at(L->pos(), is_internal);
   if (link == kEndOfChain) {
     L->Unuse();
   } else {
     DCHECK(link >= 0);
     L->link_to(link);
   }
 }
 
 
 bool Assembler::is_near(Label* L) {
@@ skipping 1717 matching lines @@
 
 
 void Assembler::bc1t(int16_t offset, uint16_t cc) {
   DCHECK(is_uint3(cc));
   Instr instr = COP1 | BC1 | cc << 18 | 1 << 16 | (offset & kImm16Mask);
   emit(instr);
 }
 
 
 // Debugging.
-int Assembler::RelocateInternalReference(byte* pc, intptr_t pc_delta) {
+int Assembler::RelocateInternalReference(RelocInfo::Mode rmode, byte* pc,
+                                         intptr_t pc_delta) {
+  if (RelocInfo::IsInternalReference(rmode)) {
+    int64_t* p = reinterpret_cast<int64_t*>(pc);
+    if (*p == kEndOfJumpChain) {
+      return 0;  // Number of instructions patched.
+    }
+    *p += pc_delta;
+    return 2;  // Number of instructions patched.
+  }
   Instr instr = instr_at(pc);
+  DCHECK(RelocInfo::IsInternalReferenceEncoded(rmode));
   DCHECK(IsJ(instr) || IsLui(instr));
   if (IsLui(instr)) {
     Instr instr_lui = instr_at(pc + 0 * Assembler::kInstrSize);
     Instr instr_ori = instr_at(pc + 1 * Assembler::kInstrSize);
     Instr instr_ori2 = instr_at(pc + 3 * Assembler::kInstrSize);
     DCHECK(IsOri(instr_ori));
     DCHECK(IsOri(instr_ori2));
     // TODO(plind): symbolic names for the shifts.
     int64_t imm = (instr_lui & static_cast<int64_t>(kImm16Mask)) << 48;
     imm |= (instr_ori & static_cast<int64_t>(kImm16Mask)) << 32;
@@ skipping 68 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);
 
   // Relocate runtime entries.
   for (RelocIterator it(desc); !it.done(); it.next()) {
     RelocInfo::Mode rmode = it.rinfo()->rmode();
-    if (rmode == RelocInfo::INTERNAL_REFERENCE) {
+    if (rmode == RelocInfo::INTERNAL_REFERENCE_ENCODED ||
+        rmode == RelocInfo::INTERNAL_REFERENCE) {
       byte* p = reinterpret_cast<byte*>(it.rinfo()->pc());
-      RelocateInternalReference(p, pc_delta);
+      RelocateInternalReference(rmode, p, pc_delta);
     }
   }
-
   DCHECK(!overflow());
 }
 
 
 void Assembler::db(uint8_t data) {
   CheckBuffer();
   *reinterpret_cast<uint8_t*>(pc_) = data;
   pc_ += sizeof(uint8_t);
 }
 
 
 void Assembler::dd(uint32_t data) {
   CheckBuffer();
   *reinterpret_cast<uint32_t*>(pc_) = data;
   pc_ += sizeof(uint32_t);
 }
 
 
+void Assembler::dd(Label* label) {
+  CheckBuffer();
+  RecordRelocInfo(RelocInfo::INTERNAL_REFERENCE);
+  if (label->is_bound()) {
+    uint64_t data = reinterpret_cast<uint64_t>(buffer_ + label->pos());
+    *reinterpret_cast<uint64_t*>(pc_) = data;
+    pc_ += sizeof(uint64_t);
+  } else {
+    uint64_t target_pos = jump_address(label);
+    emit(target_pos);
+    internal_reference_positions_.insert(label->pos());
+  }
+}
+
+
 void Assembler::emit_code_stub_address(Code* stub) {
   CheckBuffer();
   *reinterpret_cast<uint64_t*>(pc_) =
       reinterpret_cast<uint64_t>(stub->instruction_start());
   pc_ += sizeof(uint64_t);
 }
 
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
   // We do not try to reuse pool constants.
@@ skipping 60 matching lines @@
       nop();
 
       int pool_start = pc_offset();
       for (int i = 0; i < unbound_labels_count_; i++) {
         uint64_t imm64;
         imm64 = jump_address(&after_pool);
         { BlockGrowBufferScope block_buf_growth(this);
           // Buffer growth (and relocation) must be blocked for internal
           // references until associated instructions are emitted and available
           // to be patched.
-          RecordRelocInfo(RelocInfo::INTERNAL_REFERENCE);
+          RecordRelocInfo(RelocInfo::INTERNAL_REFERENCE_ENCODED);
           // TODO(plind): Verify this, presume I cannot use macro-assembler
           // here.
           lui(at, (imm64 >> 32) & kImm16Mask);
           ori(at, at, (imm64 >> 16) & kImm16Mask);
           dsll(at, at, 16);
           ori(at, at, imm64 & kImm16Mask);
         }
         jr(at);
         nop();
       }
@@ skipping 143 matching lines @@
 void Assembler::PopulateConstantPool(ConstantPoolArray* constant_pool) {
   // No out-of-line constant pool support.
   DCHECK(!FLAG_enable_ool_constant_pool);
   return;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS64