Rename A64 port to ARM64 port

src/a64/lithium-gap-resolver-a64.cc

-// Copyright 2013 the V8 project authors. 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.
-//     * Redistributions in binary form must reproduce the above
-//       copyright notice, this list of conditions and the following
-//       disclaimer in the documentation and/or other materials provided
-//       with the distribution.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-#include "v8.h"
-
-#include "a64/lithium-gap-resolver-a64.h"
-#include "a64/lithium-codegen-a64.h"
-
-namespace v8 {
-namespace internal {
-
-// We use the root register to spill a value while breaking a cycle in parallel
-// moves. We don't need access to roots while resolving the move list and using
-// the root register has two advantages:
-//  - It is not in crankshaft allocatable registers list, so it can't interfere
-//    with any of the moves we are resolving.
-//  - We don't need to push it on the stack, as we can reload it with its value
-//    once we have resolved a cycle.
-#define kSavedValue root
-
-LGapResolver::LGapResolver(LCodeGen* owner)
-    : cgen_(owner), moves_(32, owner->zone()), root_index_(0), in_cycle_(false),
-      saved_destination_(NULL), need_to_restore_root_(false) { }
-
-
-#define __ ACCESS_MASM(cgen_->masm())
-
-void LGapResolver::Resolve(LParallelMove* parallel_move) {
-  ASSERT(moves_.is_empty());
-
-  // Build up a worklist of moves.
-  BuildInitialMoveList(parallel_move);
-
-  for (int i = 0; i < moves_.length(); ++i) {
-    LMoveOperands move = moves_[i];
-
-    // Skip constants to perform them last. They don't block other moves
-    // and skipping such moves with register destinations keeps those
-    // registers free for the whole algorithm.
-    if (!move.IsEliminated() && !move.source()->IsConstantOperand()) {
-      root_index_ = i;  // Any cycle is found when we reach this move again.
-      PerformMove(i);
-      if (in_cycle_) RestoreValue();
-    }
-  }
-
-  // Perform the moves with constant sources.
-  for (int i = 0; i < moves_.length(); ++i) {
-    LMoveOperands move = moves_[i];
-
-    if (!move.IsEliminated()) {
-      ASSERT(move.source()->IsConstantOperand());
-      EmitMove(i);
-    }
-  }
-
-  if (need_to_restore_root_) {
-    ASSERT(kSavedValue.Is(root));
-    __ InitializeRootRegister();
-    need_to_restore_root_ = false;
-  }
-
-  moves_.Rewind(0);
-}
-
-
-void LGapResolver::BuildInitialMoveList(LParallelMove* parallel_move) {
-  // Perform a linear sweep of the moves to add them to the initial list of
-  // moves to perform, ignoring any move that is redundant (the source is
-  // the same as the destination, the destination is ignored and
-  // unallocated, or the move was already eliminated).
-  const ZoneList<LMoveOperands>* moves = parallel_move->move_operands();
-  for (int i = 0; i < moves->length(); ++i) {
-    LMoveOperands move = moves->at(i);
-    if (!move.IsRedundant()) moves_.Add(move, cgen_->zone());
-  }
-  Verify();
-}
-
-
-void LGapResolver::PerformMove(int index) {
-  // Each call to this function performs a move and deletes it from the move
-  // graph. We first recursively perform any move blocking this one. We
-  // mark a move as "pending" on entry to PerformMove in order to detect
-  // cycles in the move graph.
-  LMoveOperands& current_move = moves_[index];
-
-  ASSERT(!current_move.IsPending());
-  ASSERT(!current_move.IsRedundant());
-
-  // Clear this move's destination to indicate a pending move.  The actual
-  // destination is saved in a stack allocated local. Multiple moves can
-  // be pending because this function is recursive.
-  ASSERT(current_move.source() != NULL);  // Otherwise it will look eliminated.
-  LOperand* destination = current_move.destination();
-  current_move.set_destination(NULL);
-
-  // Perform a depth-first traversal of the move graph to resolve
-  // dependencies. Any unperformed, unpending move with a source the same
-  // as this one's destination blocks this one so recursively perform all
-  // such moves.
-  for (int i = 0; i < moves_.length(); ++i) {
-    LMoveOperands other_move = moves_[i];
-    if (other_move.Blocks(destination) && !other_move.IsPending()) {
-      PerformMove(i);
-      // If there is a blocking, pending move it must be moves_[root_index_]
-      // and all other moves with the same source as moves_[root_index_] are
-      // sucessfully executed (because they are cycle-free) by this loop.
-    }
-  }
-
-  // We are about to resolve this move and don't need it marked as
-  // pending, so restore its destination.
-  current_move.set_destination(destination);
-
-  // The move may be blocked on a pending move, which must be the starting move.
-  // In this case, we have a cycle, and we save the source of this move to
-  // a scratch register to break it.
-  LMoveOperands other_move = moves_[root_index_];
-  if (other_move.Blocks(destination)) {
-    ASSERT(other_move.IsPending());
-    BreakCycle(index);
-    return;
-  }
-
-  // This move is no longer blocked.
-  EmitMove(index);
-}
-
-
-void LGapResolver::Verify() {
-#ifdef ENABLE_SLOW_ASSERTS
-  // No operand should be the destination for more than one move.
-  for (int i = 0; i < moves_.length(); ++i) {
-    LOperand* destination = moves_[i].destination();
-    for (int j = i + 1; j < moves_.length(); ++j) {
-      SLOW_ASSERT(!destination->Equals(moves_[j].destination()));
-    }
-  }
-#endif
-}
-
-
-void LGapResolver::BreakCycle(int index) {
-  ASSERT(moves_[index].destination()->Equals(moves_[root_index_].source()));
-  ASSERT(!in_cycle_);
-
-  // We use a register which is not allocatable by crankshaft to break the cycle
-  // to be sure it doesn't interfere with the moves we are resolving.
-  ASSERT(!kSavedValue.IsAllocatable());
-  need_to_restore_root_ = true;
-
-  // We save in a register the source of that move and we remember its
-  // destination. Then we mark this move as resolved so the cycle is
-  // broken and we can perform the other moves.
-  in_cycle_ = true;
-  LOperand* source = moves_[index].source();
-  saved_destination_ = moves_[index].destination();
-
-  if (source->IsRegister()) {
-    __ Mov(kSavedValue, cgen_->ToRegister(source));
-  } else if (source->IsStackSlot()) {
-    __ Ldr(kSavedValue, cgen_->ToMemOperand(source));
-  } else if (source->IsDoubleRegister()) {
-    // TODO(all): We should use a double register to store the value to avoid
-    // the penalty of the mov across register banks. We are going to reserve
-    // d31 to hold 0.0 value. We could clobber this register while breaking the
-    // cycle and restore it after like we do with the root register.
-    // LGapResolver::RestoreValue() will need to be updated as well when we'll
-    // do that.
-    __ Fmov(kSavedValue, cgen_->ToDoubleRegister(source));
-  } else if (source->IsDoubleStackSlot()) {
-    __ Ldr(kSavedValue, cgen_->ToMemOperand(source));
-  } else {
-    UNREACHABLE();
-  }
-
-  // Mark this move as resolved.
-  // This move will be actually performed by moving the saved value to this
-  // move's destination in LGapResolver::RestoreValue().
-  moves_[index].Eliminate();
-}
-
-
-void LGapResolver::RestoreValue() {
-  ASSERT(in_cycle_);
-  ASSERT(saved_destination_ != NULL);
-
-  if (saved_destination_->IsRegister()) {
-    __ Mov(cgen_->ToRegister(saved_destination_), kSavedValue);
-  } else if (saved_destination_->IsStackSlot()) {
-    __ Str(kSavedValue, cgen_->ToMemOperand(saved_destination_));
-  } else if (saved_destination_->IsDoubleRegister()) {
-    __ Fmov(cgen_->ToDoubleRegister(saved_destination_), kSavedValue);
-  } else if (saved_destination_->IsDoubleStackSlot()) {
-    __ Str(kSavedValue, cgen_->ToMemOperand(saved_destination_));
-  } else {
-    UNREACHABLE();
-  }
-
-  in_cycle_ = false;
-  saved_destination_ = NULL;
-}
-
-
-void LGapResolver::EmitMove(int index) {
-  LOperand* source = moves_[index].source();
-  LOperand* destination = moves_[index].destination();
-
-  // Dispatch on the source and destination operand kinds.  Not all
-  // combinations are possible.
-
-  if (source->IsRegister()) {
-    Register source_register = cgen_->ToRegister(source);
-    if (destination->IsRegister()) {
-      __ Mov(cgen_->ToRegister(destination), source_register);
-    } else {
-      ASSERT(destination->IsStackSlot());
-      __ Str(source_register, cgen_->ToMemOperand(destination));
-    }
-
-  } else if (source->IsStackSlot()) {
-    MemOperand source_operand = cgen_->ToMemOperand(source);
-    if (destination->IsRegister()) {
-      __ Ldr(cgen_->ToRegister(destination), source_operand);
-    } else {
-      ASSERT(destination->IsStackSlot());
-      EmitStackSlotMove(index);
-    }
-
-  } else if (source->IsConstantOperand()) {
-    LConstantOperand* constant_source = LConstantOperand::cast(source);
-    if (destination->IsRegister()) {
-      Register dst = cgen_->ToRegister(destination);
-      if (cgen_->IsSmi(constant_source)) {
-        __ Mov(dst, cgen_->ToSmi(constant_source));
-      } else if (cgen_->IsInteger32Constant(constant_source)) {
-        __ Mov(dst, cgen_->ToInteger32(constant_source));
-      } else {
-        __ LoadObject(dst, cgen_->ToHandle(constant_source));
-      }
-    } else if (destination->IsDoubleRegister()) {
-      DoubleRegister result = cgen_->ToDoubleRegister(destination);
-      __ Fmov(result, cgen_->ToDouble(constant_source));
-    } else {
-      ASSERT(destination->IsStackSlot());
-      ASSERT(!in_cycle_);  // Constant moves happen after all cycles are gone.
-      need_to_restore_root_ = true;
-      if (cgen_->IsSmi(constant_source)) {
-        __ Mov(kSavedValue, cgen_->ToSmi(constant_source));
-      } else if (cgen_->IsInteger32Constant(constant_source)) {
-        __ Mov(kSavedValue, cgen_->ToInteger32(constant_source));
-      } else {
-        __ LoadObject(kSavedValue, cgen_->ToHandle(constant_source));
-      }
-      __ Str(kSavedValue, cgen_->ToMemOperand(destination));
-    }
-
-  } else if (source->IsDoubleRegister()) {
-    DoubleRegister src = cgen_->ToDoubleRegister(source);
-    if (destination->IsDoubleRegister()) {
-      __ Fmov(cgen_->ToDoubleRegister(destination), src);
-    } else {
-      ASSERT(destination->IsDoubleStackSlot());
-      __ Str(src, cgen_->ToMemOperand(destination));
-    }
-
-  } else if (source->IsDoubleStackSlot()) {
-    MemOperand src = cgen_->ToMemOperand(source);
-    if (destination->IsDoubleRegister()) {
-      __ Ldr(cgen_->ToDoubleRegister(destination), src);
-    } else {
-      ASSERT(destination->IsDoubleStackSlot());
-      EmitStackSlotMove(index);
-    }
-
-  } else {
-    UNREACHABLE();
-  }
-
-  // The move has been emitted, we can eliminate it.
-  moves_[index].Eliminate();
-}
-
-
-void LGapResolver::EmitStackSlotMove(int index) {
-  // We need a temp register to perform a stack slot to stack slot move, and
-  // the register must not be involved in breaking cycles.
-
-  // Use the Crankshaft double scratch register as the temporary.
-  DoubleRegister temp = crankshaft_fp_scratch;
-
-  LOperand* src = moves_[index].source();
-  LOperand* dst = moves_[index].destination();
-
-  ASSERT(src->IsStackSlot());
-  ASSERT(dst->IsStackSlot());
-  __ Ldr(temp, cgen_->ToMemOperand(src));
-  __ Str(temp, cgen_->ToMemOperand(dst));
-}
-
-} }  // namespace v8::internal