Upgrade V8 to 5.1.281.57 DO NOT MERGE
FPIIM-449
Change-Id: Id981b686b4d587ac31697662eb98bb34be42ad90
(cherry picked from commit 3b9bc31999c9787eb726ecdbfd5796bfdec32a18)
diff --git a/src/crankshaft/s390/lithium-gap-resolver-s390.cc b/src/crankshaft/s390/lithium-gap-resolver-s390.cc
new file mode 100644
index 0000000..cffcede
--- /dev/null
+++ b/src/crankshaft/s390/lithium-gap-resolver-s390.cc
@@ -0,0 +1,280 @@
+// Copyright 2015 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 "src/crankshaft/s390/lithium-gap-resolver-s390.h"
+
+#include "src/crankshaft/s390/lithium-codegen-s390.h"
+
+namespace v8 {
+namespace internal {
+
+static const Register kSavedValueRegister = {1};
+
+LGapResolver::LGapResolver(LCodeGen* owner)
+ : cgen_(owner),
+ moves_(32, owner->zone()),
+ root_index_(0),
+ in_cycle_(false),
+ saved_destination_(NULL) {}
+
+void LGapResolver::Resolve(LParallelMove* parallel_move) {
+ DCHECK(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 by reaching this move again.
+ PerformMove(i);
+ if (in_cycle_) {
+ RestoreValue();
+ }
+ }
+ }
+
+ // Perform the moves with constant sources.
+ for (int i = 0; i < moves_.length(); ++i) {
+ if (!moves_[i].IsEliminated()) {
+ DCHECK(moves_[i].source()->IsConstantOperand());
+ EmitMove(i);
+ }
+ }
+
+ 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.
+
+ // We can only find a cycle, when doing a depth-first traversal of moves,
+ // be encountering the starting move again. So by spilling the source of
+ // the starting move, we break the cycle. All moves are then unblocked,
+ // and the starting move is completed by writing the spilled value to
+ // its destination. All other moves from the spilled source have been
+ // completed prior to breaking the cycle.
+ // An additional complication is that moves to MemOperands with large
+ // offsets (more than 1K or 4K) require us to spill this spilled value to
+ // the stack, to free up the register.
+ DCHECK(!moves_[index].IsPending());
+ DCHECK(!moves_[index].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.
+ DCHECK(moves_[index].source() != NULL); // Or else it will look eliminated.
+ LOperand* destination = moves_[index].destination();
+ moves_[index].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.
+ moves_[index].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)) {
+ DCHECK(other_move.IsPending());
+ BreakCycle(index);
+ return;
+ }
+
+ // This move is no longer blocked.
+ EmitMove(index);
+}
+
+void LGapResolver::Verify() {
+#ifdef ENABLE_SLOW_DCHECKS
+ // 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_DCHECK(!destination->Equals(moves_[j].destination()));
+ }
+ }
+#endif
+}
+
+#define __ ACCESS_MASM(cgen_->masm())
+
+void LGapResolver::BreakCycle(int index) {
+ // We save in a register the value that should end up in the source of
+ // moves_[root_index]. After performing all moves in the tree rooted
+ // in that move, we save the value to that source.
+ DCHECK(moves_[index].destination()->Equals(moves_[root_index_].source()));
+ DCHECK(!in_cycle_);
+ in_cycle_ = true;
+ LOperand* source = moves_[index].source();
+ saved_destination_ = moves_[index].destination();
+ if (source->IsRegister()) {
+ __ LoadRR(kSavedValueRegister, cgen_->ToRegister(source));
+ } else if (source->IsStackSlot()) {
+ __ LoadP(kSavedValueRegister, cgen_->ToMemOperand(source));
+ } else if (source->IsDoubleRegister()) {
+ __ ldr(kScratchDoubleReg, cgen_->ToDoubleRegister(source));
+ } else if (source->IsDoubleStackSlot()) {
+ __ LoadDouble(kScratchDoubleReg, cgen_->ToMemOperand(source));
+ } else {
+ UNREACHABLE();
+ }
+ // This move will be done by restoring the saved value to the destination.
+ moves_[index].Eliminate();
+}
+
+void LGapResolver::RestoreValue() {
+ DCHECK(in_cycle_);
+ DCHECK(saved_destination_ != NULL);
+
+ // Spilled value is in kSavedValueRegister or kSavedDoubleValueRegister.
+ if (saved_destination_->IsRegister()) {
+ __ LoadRR(cgen_->ToRegister(saved_destination_), kSavedValueRegister);
+ } else if (saved_destination_->IsStackSlot()) {
+ __ StoreP(kSavedValueRegister, cgen_->ToMemOperand(saved_destination_));
+ } else if (saved_destination_->IsDoubleRegister()) {
+ __ ldr(cgen_->ToDoubleRegister(saved_destination_), kScratchDoubleReg);
+ } else if (saved_destination_->IsDoubleStackSlot()) {
+ __ StoreDouble(kScratchDoubleReg, 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()) {
+ __ LoadRR(cgen_->ToRegister(destination), source_register);
+ } else {
+ DCHECK(destination->IsStackSlot());
+ __ StoreP(source_register, cgen_->ToMemOperand(destination));
+ }
+ } else if (source->IsStackSlot()) {
+ MemOperand source_operand = cgen_->ToMemOperand(source);
+ if (destination->IsRegister()) {
+ __ LoadP(cgen_->ToRegister(destination), source_operand);
+ } else {
+ DCHECK(destination->IsStackSlot());
+ MemOperand destination_operand = cgen_->ToMemOperand(destination);
+ if (in_cycle_) {
+ __ LoadP(ip, source_operand);
+ __ StoreP(ip, destination_operand);
+ } else {
+ __ LoadP(kSavedValueRegister, source_operand);
+ __ StoreP(kSavedValueRegister, destination_operand);
+ }
+ }
+
+ } else if (source->IsConstantOperand()) {
+ LConstantOperand* constant_source = LConstantOperand::cast(source);
+ if (destination->IsRegister()) {
+ Register dst = cgen_->ToRegister(destination);
+ if (cgen_->IsInteger32(constant_source)) {
+ cgen_->EmitLoadIntegerConstant(constant_source, dst);
+ } else {
+ __ Move(dst, cgen_->ToHandle(constant_source));
+ }
+ } else if (destination->IsDoubleRegister()) {
+ DoubleRegister result = cgen_->ToDoubleRegister(destination);
+ double v = cgen_->ToDouble(constant_source);
+ __ LoadDoubleLiteral(result, v, ip);
+ } else {
+ DCHECK(destination->IsStackSlot());
+ DCHECK(!in_cycle_); // Constant moves happen after all cycles are gone.
+ if (cgen_->IsInteger32(constant_source)) {
+ cgen_->EmitLoadIntegerConstant(constant_source, kSavedValueRegister);
+ } else {
+ __ Move(kSavedValueRegister, cgen_->ToHandle(constant_source));
+ }
+ __ StoreP(kSavedValueRegister, cgen_->ToMemOperand(destination));
+ }
+
+ } else if (source->IsDoubleRegister()) {
+ DoubleRegister source_register = cgen_->ToDoubleRegister(source);
+ if (destination->IsDoubleRegister()) {
+ __ ldr(cgen_->ToDoubleRegister(destination), source_register);
+ } else {
+ DCHECK(destination->IsDoubleStackSlot());
+ __ StoreDouble(source_register, cgen_->ToMemOperand(destination));
+ }
+
+ } else if (source->IsDoubleStackSlot()) {
+ MemOperand source_operand = cgen_->ToMemOperand(source);
+ if (destination->IsDoubleRegister()) {
+ __ LoadDouble(cgen_->ToDoubleRegister(destination), source_operand);
+ } else {
+ DCHECK(destination->IsDoubleStackSlot());
+ MemOperand destination_operand = cgen_->ToMemOperand(destination);
+ if (in_cycle_) {
+// kSavedDoubleValueRegister was used to break the cycle,
+// but kSavedValueRegister is free.
+#if V8_TARGET_ARCH_S390X
+ __ lg(kSavedValueRegister, source_operand);
+ __ stg(kSavedValueRegister, destination_operand);
+#else
+ MemOperand source_high_operand = cgen_->ToHighMemOperand(source);
+ MemOperand destination_high_operand =
+ cgen_->ToHighMemOperand(destination);
+ __ LoadlW(kSavedValueRegister, source_operand);
+ __ StoreW(kSavedValueRegister, destination_operand);
+ __ LoadlW(kSavedValueRegister, source_high_operand);
+ __ StoreW(kSavedValueRegister, destination_high_operand);
+#endif
+ } else {
+ __ LoadDouble(kScratchDoubleReg, source_operand);
+ __ StoreDouble(kScratchDoubleReg, destination_operand);
+ }
+ }
+ } else {
+ UNREACHABLE();
+ }
+
+ moves_[index].Eliminate();
+}
+
+#undef __
+} // namespace internal
+} // namespace v8