diff options
Diffstat (limited to 'compiler/optimizing')
| -rw-r--r-- | compiler/optimizing/bounds_check_elimination.cc | 598 | ||||
| -rw-r--r-- | compiler/optimizing/bounds_check_elimination_test.cc | 53 | ||||
| -rw-r--r-- | compiler/optimizing/nodes.cc | 75 | ||||
| -rw-r--r-- | compiler/optimizing/nodes.h | 37 |
4 files changed, 598 insertions, 165 deletions
diff --git a/compiler/optimizing/bounds_check_elimination.cc b/compiler/optimizing/bounds_check_elimination.cc index b2b54965b5..f8550c2b47 100644 --- a/compiler/optimizing/bounds_check_elimination.cc +++ b/compiler/optimizing/bounds_check_elimination.cc @@ -126,11 +126,14 @@ class ValueBound : public ValueObject { return instruction_ == bound.instruction_ && constant_ == bound.constant_; } - static HInstruction* FromArrayLengthToNewArrayIfPossible(HInstruction* instruction) { - // Null check on the NewArray should have been eliminated by instruction - // simplifier already. - if (instruction->IsArrayLength() && instruction->InputAt(0)->IsNewArray()) { - return instruction->InputAt(0)->AsNewArray(); + static HInstruction* FromArrayLengthToArray(HInstruction* instruction) { + DCHECK(instruction->IsArrayLength() || instruction->IsNewArray()); + if (instruction->IsArrayLength()) { + HInstruction* input = instruction->InputAt(0); + if (input->IsNullCheck()) { + input = input->AsNullCheck()->InputAt(0); + } + return input; } return instruction; } @@ -146,8 +149,9 @@ class ValueBound : public ValueObject { // Some bounds are created with HNewArray* as the instruction instead // of HArrayLength*. They are treated the same. - instruction1 = FromArrayLengthToNewArrayIfPossible(instruction1); - instruction2 = FromArrayLengthToNewArrayIfPossible(instruction2); + // HArrayLength with the same array input are considered equal also. + instruction1 = FromArrayLengthToArray(instruction1); + instruction2 = FromArrayLengthToArray(instruction2); return instruction1 == instruction2; } @@ -271,7 +275,7 @@ class ArrayAccessInsideLoopFinder : public ValueObject { // Loop header of loop_info. Exiting loop is normal. return false; } - const GrowableArray<HBasicBlock*> successors = block->GetSuccessors(); + const GrowableArray<HBasicBlock*>& successors = block->GetSuccessors(); for (size_t i = 0; i < successors.Size(); i++) { if (!loop_info->Contains(*successors.Get(i))) { // One of the successors exits the loop. @@ -293,8 +297,14 @@ class ArrayAccessInsideLoopFinder : public ValueObject { void Run() { HLoopInformation* loop_info = induction_variable_->GetBlock()->GetLoopInformation(); - for (HBlocksInLoopIterator it_loop(*loop_info); !it_loop.Done(); it_loop.Advance()) { - HBasicBlock* block = it_loop.Current(); + HBlocksInLoopReversePostOrderIterator it_loop(*loop_info); + HBasicBlock* block = it_loop.Current(); + DCHECK(block == induction_variable_->GetBlock()); + // Skip loop header. Since narrowed value range of a MonotonicValueRange only + // applies to the loop body (after the test at the end of the loop header). + it_loop.Advance(); + for (; !it_loop.Done(); it_loop.Advance()) { + block = it_loop.Current(); DCHECK(block->IsInLoop()); if (!DominatesAllBackEdges(block, loop_info)) { // In order not to trigger deoptimization unnecessarily, make sure @@ -308,30 +318,35 @@ class ArrayAccessInsideLoopFinder : public ValueObject { // that the loop will loop through the full monotonic value range from // initial_ to end_. So adding deoptimization might be too aggressive and can // trigger deoptimization unnecessarily even if the loop won't actually throw - // AIOOBE. Otherwise, the loop induction variable is going to cover the full - // monotonic value range from initial_ to end_, and deoptimizations are added - // iff the loop will throw AIOOBE. + // AIOOBE. found_array_length_ = nullptr; return; } for (HInstruction* instruction = block->GetFirstInstruction(); instruction != nullptr; instruction = instruction->GetNext()) { - if (!instruction->IsArrayGet() && !instruction->IsArraySet()) { + if (!instruction->IsBoundsCheck()) { continue; } - HInstruction* index = instruction->InputAt(1); - if (!index->IsBoundsCheck()) { + + HInstruction* length_value = instruction->InputAt(1); + if (length_value->IsIntConstant()) { + // TODO: may optimize for constant case. continue; } - HArrayLength* array_length = index->InputAt(1)->AsArrayLength(); - if (array_length == nullptr) { - DCHECK(index->InputAt(1)->IsIntConstant()); - // TODO: may optimize for constant case. + DCHECK(!length_value->IsPhi()); + if (length_value->IsPhi()) { + // Outer loop shouldn't collect bounds checks inside inner + // loop because the inner loop body doen't dominate + // outer loop's back edges. However just to be on the safe side, + // if there are any such cases, we just skip over them. continue; } + DCHECK(length_value->IsArrayLength()); + HArrayLength* array_length = length_value->AsArrayLength(); + HInstruction* array = array_length->InputAt(0); if (array->IsNullCheck()) { array = array->AsNullCheck()->InputAt(0); @@ -347,7 +362,7 @@ class ArrayAccessInsideLoopFinder : public ValueObject { continue; } - index = index->AsBoundsCheck()->InputAt(0); + HInstruction* index = instruction->AsBoundsCheck()->InputAt(0); HInstruction* left = index; int32_t right = 0; if (left == induction_variable_ || @@ -375,7 +390,7 @@ class ArrayAccessInsideLoopFinder : public ValueObject { // The instruction that corresponds to a MonotonicValueRange. HInstruction* induction_variable_; - // The array length of the array that's accessed inside the loop. + // The array length of the array that's accessed inside the loop body. HArrayLength* found_array_length_; // The lowest and highest constant offsets relative to induction variable @@ -411,6 +426,8 @@ class ValueRange : public ArenaObject<kArenaAllocMisc> { ValueBound GetLower() const { return lower_; } ValueBound GetUpper() const { return upper_; } + bool IsConstantValueRange() { return lower_.IsConstant() && upper_.IsConstant(); } + // If it's certain that this value range fits in other_range. virtual bool FitsIn(ValueRange* other_range) const { if (other_range == nullptr) { @@ -495,13 +512,30 @@ class MonotonicValueRange : public ValueRange { ValueBound GetBound() const { return bound_; } void SetEnd(HInstruction* end) { end_ = end; } void SetInclusive(bool inclusive) { inclusive_ = inclusive; } - HBasicBlock* GetLoopHead() const { + HBasicBlock* GetLoopHeader() const { DCHECK(induction_variable_->GetBlock()->IsLoopHeader()); return induction_variable_->GetBlock(); } MonotonicValueRange* AsMonotonicValueRange() OVERRIDE { return this; } + HBasicBlock* GetLoopHeaderSuccesorInLoop() { + HBasicBlock* header = GetLoopHeader(); + HInstruction* instruction = header->GetLastInstruction(); + DCHECK(instruction->IsIf()); + HIf* h_if = instruction->AsIf(); + HLoopInformation* loop_info = header->GetLoopInformation(); + bool true_successor_in_loop = loop_info->Contains(*h_if->IfTrueSuccessor()); + bool false_successor_in_loop = loop_info->Contains(*h_if->IfFalseSuccessor()); + + // Just in case it's some strange loop structure. + if (true_successor_in_loop && false_successor_in_loop) { + return nullptr; + } + DCHECK(true_successor_in_loop || false_successor_in_loop); + return false_successor_in_loop ? h_if->IfFalseSuccessor() : h_if->IfTrueSuccessor(); + } + // If it's certain that this value range fits in other_range. bool FitsIn(ValueRange* other_range) const OVERRIDE { if (other_range == nullptr) { @@ -593,12 +627,114 @@ class MonotonicValueRange : public ValueRange { } } + // Try to add HDeoptimize's in the loop pre-header first to narrow this range. + // For example, this loop: + // + // for (int i = start; i < end; i++) { + // array[i - 1] = array[i] + array[i + 1]; + // } + // + // will be transformed to: + // + // int array_length_in_loop_body_if_needed; + // if (start >= end) { + // array_length_in_loop_body_if_needed = 0; + // } else { + // if (start < 1) deoptimize(); + // if (array == null) deoptimize(); + // array_length = array.length; + // if (end > array_length - 1) deoptimize; + // array_length_in_loop_body_if_needed = array_length; + // } + // for (int i = start; i < end; i++) { + // // No more null check and bounds check. + // // array.length value is replaced with array_length_in_loop_body_if_needed + // // in the loop body. + // array[i - 1] = array[i] + array[i + 1]; + // } + // + // We basically first go through the loop body and find those array accesses whose + // index is at a constant offset from the induction variable ('i' in the above example), + // and update offset_low and offset_high along the way. We then add the following + // deoptimizations in the loop pre-header (suppose end is not inclusive). + // if (start < -offset_low) deoptimize(); + // if (end >= array.length - offset_high) deoptimize(); + // It might be necessary to first hoist array.length (and the null check on it) out of + // the loop with another deoptimization. + // + // In order not to trigger deoptimization unnecessarily, we want to make a strong + // guarantee that no deoptimization is triggered if the loop body itself doesn't + // throw AIOOBE. (It's the same as saying if deoptimization is triggered, the loop + // body must throw AIOOBE). + // This is achieved by the following: + // 1) We only process loops that iterate through the full monotonic range from + // initial_ to end_. We do the following checks to make sure that's the case: + // a) The loop doesn't have early exit (via break, return, etc.) + // b) The increment_ is 1/-1. An increment of 2, for example, may skip end_. + // 2) We only collect array accesses of blocks in the loop body that dominate + // all loop back edges, these array accesses are guaranteed to happen + // at each loop iteration. + // With 1) and 2), if the loop body doesn't throw AIOOBE, collected array accesses + // when the induction variable is at initial_ and end_ must be in a legal range. + // Since the added deoptimizations are basically checking the induction variable + // at initial_ and end_ values, no deoptimization will be triggered either. + // + // A special case is the loop body isn't entered at all. In that case, we may still + // add deoptimization due to the analysis described above. In order not to trigger + // deoptimization, we do a test between initial_ and end_ first and skip over + // the added deoptimization. + ValueRange* NarrowWithDeoptimization() { + if (increment_ != 1 && increment_ != -1) { + // In order not to trigger deoptimization unnecessarily, we want to + // make sure the loop iterates through the full range from initial_ to + // end_ so that boundaries are covered by the loop. An increment of 2, + // for example, may skip end_. + return this; + } + + if (end_ == nullptr) { + // No full info to add deoptimization. + return this; + } + + HBasicBlock* header = induction_variable_->GetBlock(); + DCHECK(header->IsLoopHeader()); + HBasicBlock* pre_header = header->GetLoopInformation()->GetPreHeader(); + if (!initial_->GetBlock()->Dominates(pre_header) || + !end_->GetBlock()->Dominates(pre_header)) { + // Can't add a check in loop pre-header if the value isn't available there. + return this; + } + + ArrayAccessInsideLoopFinder finder(induction_variable_); + + if (!finder.HasFoundArrayLength()) { + // No array access was found inside the loop that can benefit + // from deoptimization. + return this; + } + + if (!AddDeoptimization(finder)) { + return this; + } + + // After added deoptimizations, induction variable fits in + // [-offset_low, array.length-1-offset_high], adjusted with collected offsets. + ValueBound lower = ValueBound(0, -finder.GetOffsetLow()); + ValueBound upper = ValueBound(finder.GetFoundArrayLength(), -1 - finder.GetOffsetHigh()); + // We've narrowed the range after added deoptimizations. + return new (GetAllocator()) ValueRange(GetAllocator(), lower, upper); + } + // Returns true if adding a (constant >= value) check for deoptimization // is allowed and will benefit compiled code. - bool CanAddDeoptimizationConstant(HInstruction* value, - int32_t constant, - bool* is_proven) { + bool CanAddDeoptimizationConstant(HInstruction* value, int32_t constant, bool* is_proven) { *is_proven = false; + HBasicBlock* header = induction_variable_->GetBlock(); + DCHECK(header->IsLoopHeader()); + HBasicBlock* pre_header = header->GetLoopInformation()->GetPreHeader(); + DCHECK(value->GetBlock()->Dominates(pre_header)); + // See if we can prove the relationship first. if (value->IsIntConstant()) { if (value->AsIntConstant()->GetValue() >= constant) { @@ -615,22 +751,118 @@ class MonotonicValueRange : public ValueRange { return true; } + // Try to filter out cases that the loop entry test will never be true. + bool LoopEntryTestUseful() { + if (initial_->IsIntConstant() && end_->IsIntConstant()) { + int32_t initial_val = initial_->AsIntConstant()->GetValue(); + int32_t end_val = end_->AsIntConstant()->GetValue(); + if (increment_ == 1) { + if (inclusive_) { + return initial_val > end_val; + } else { + return initial_val >= end_val; + } + } else { + DCHECK(increment_ == -1); + if (inclusive_) { + return initial_val < end_val; + } else { + return initial_val <= end_val; + } + } + } + return true; + } + + // Returns the block for adding deoptimization. + HBasicBlock* TransformLoopForDeoptimizationIfNeeded() { + HBasicBlock* header = induction_variable_->GetBlock(); + DCHECK(header->IsLoopHeader()); + HBasicBlock* pre_header = header->GetLoopInformation()->GetPreHeader(); + // Deoptimization is only added when both initial_ and end_ are defined + // before the loop. + DCHECK(initial_->GetBlock()->Dominates(pre_header)); + DCHECK(end_->GetBlock()->Dominates(pre_header)); + + // If it can be proven the loop body is definitely entered (unless exception + // is thrown in the loop header for which triggering deoptimization is fine), + // there is no need for tranforming the loop. In that case, deoptimization + // will just be added in the loop pre-header. + if (!LoopEntryTestUseful()) { + return pre_header; + } + + HGraph* graph = header->GetGraph(); + graph->TransformLoopHeaderForBCE(header); + HBasicBlock* new_pre_header = header->GetDominator(); + DCHECK(new_pre_header == header->GetLoopInformation()->GetPreHeader()); + HBasicBlock* if_block = new_pre_header->GetDominator(); + HBasicBlock* dummy_block = if_block->GetSuccessors().Get(0); // True successor. + HBasicBlock* deopt_block = if_block->GetSuccessors().Get(1); // False successor. + + dummy_block->AddInstruction(new (graph->GetArena()) HGoto()); + deopt_block->AddInstruction(new (graph->GetArena()) HGoto()); + new_pre_header->AddInstruction(new (graph->GetArena()) HGoto()); + return deopt_block; + } + + // Adds a test between initial_ and end_ to see if the loop body is entered. + // If the loop body isn't entered at all, it jumps to the loop pre-header (after + // transformation) to avoid any deoptimization. + void AddLoopBodyEntryTest() { + HBasicBlock* header = induction_variable_->GetBlock(); + DCHECK(header->IsLoopHeader()); + HBasicBlock* pre_header = header->GetLoopInformation()->GetPreHeader(); + HBasicBlock* if_block = pre_header->GetDominator(); + HGraph* graph = header->GetGraph(); + + HCondition* cond; + if (increment_ == 1) { + if (inclusive_) { + cond = new (graph->GetArena()) HGreaterThan(initial_, end_); + } else { + cond = new (graph->GetArena()) HGreaterThanOrEqual(initial_, end_); + } + } else { + DCHECK(increment_ == -1); + if (inclusive_) { + cond = new (graph->GetArena()) HLessThan(initial_, end_); + } else { + cond = new (graph->GetArena()) HLessThanOrEqual(initial_, end_); + } + } + HIf* h_if = new (graph->GetArena()) HIf(cond); + if_block->AddInstruction(cond); + if_block->AddInstruction(h_if); + } + // Adds a check that (value >= constant), and HDeoptimize otherwise. void AddDeoptimizationConstant(HInstruction* value, - int32_t constant) { - HBasicBlock* block = induction_variable_->GetBlock(); - DCHECK(block->IsLoopHeader()); - HGraph* graph = block->GetGraph(); - HBasicBlock* pre_header = block->GetLoopInformation()->GetPreHeader(); - HSuspendCheck* suspend_check = block->GetLoopInformation()->GetSuspendCheck(); + int32_t constant, + HBasicBlock* deopt_block, + bool loop_entry_test_block_added) { + HBasicBlock* header = induction_variable_->GetBlock(); + DCHECK(header->IsLoopHeader()); + HBasicBlock* pre_header = header->GetDominator(); + if (loop_entry_test_block_added) { + DCHECK(deopt_block->GetSuccessors().Get(0) == pre_header); + } else { + DCHECK(deopt_block == pre_header); + } + HGraph* graph = header->GetGraph(); + HSuspendCheck* suspend_check = header->GetLoopInformation()->GetSuspendCheck(); + if (loop_entry_test_block_added) { + DCHECK_EQ(deopt_block, header->GetDominator()->GetDominator()->GetSuccessors().Get(1)); + } + HIntConstant* const_instr = graph->GetIntConstant(constant); HCondition* cond = new (graph->GetArena()) HLessThan(value, const_instr); HDeoptimize* deoptimize = new (graph->GetArena()) HDeoptimize(cond, suspend_check->GetDexPc()); - pre_header->InsertInstructionBefore(cond, pre_header->GetLastInstruction()); - pre_header->InsertInstructionBefore(deoptimize, pre_header->GetLastInstruction()); + deopt_block->InsertInstructionBefore(cond, deopt_block->GetLastInstruction()); + deopt_block->InsertInstructionBefore(deoptimize, deopt_block->GetLastInstruction()); deoptimize->CopyEnvironmentFromWithLoopPhiAdjustment( - suspend_check->GetEnvironment(), block); + suspend_check->GetEnvironment(), header); } // Returns true if adding a (value <= array_length + offset) check for deoptimization @@ -640,6 +872,26 @@ class MonotonicValueRange : public ValueRange { int32_t offset, bool* is_proven) { *is_proven = false; + HBasicBlock* header = induction_variable_->GetBlock(); + DCHECK(header->IsLoopHeader()); + HBasicBlock* pre_header = header->GetLoopInformation()->GetPreHeader(); + DCHECK(value->GetBlock()->Dominates(pre_header)); + + if (array_length->GetBlock() == header) { + // array_length_in_loop_body_if_needed only has correct value when the loop + // body is entered. We bail out in this case. Usually array_length defined + // in the loop header is already hoisted by licm. + return false; + } else { + // array_length is defined either before the loop header already, or in + // the loop body since it's used in the loop body. If it's defined in the loop body, + // a phi array_length_in_loop_body_if_needed is used to replace it. In that case, + // all the uses of array_length must be dominated by its definition in the loop + // body. array_length_in_loop_body_if_needed is guaranteed to be the same as + // array_length once the loop body is entered so all the uses of the phi will + // use the correct value. + } + if (offset > 0) { // There might be overflow issue. // TODO: handle this, possibly with some distance relationship between @@ -667,56 +919,99 @@ class MonotonicValueRange : public ValueRange { // Adds a check that (value <= array_length + offset), and HDeoptimize otherwise. void AddDeoptimizationArrayLength(HInstruction* value, HArrayLength* array_length, - int32_t offset) { - HBasicBlock* block = induction_variable_->GetBlock(); - DCHECK(block->IsLoopHeader()); - HGraph* graph = block->GetGraph(); - HBasicBlock* pre_header = block->GetLoopInformation()->GetPreHeader(); - HSuspendCheck* suspend_check = block->GetLoopInformation()->GetSuspendCheck(); + int32_t offset, + HBasicBlock* deopt_block, + bool loop_entry_test_block_added) { + HBasicBlock* header = induction_variable_->GetBlock(); + DCHECK(header->IsLoopHeader()); + HBasicBlock* pre_header = header->GetDominator(); + if (loop_entry_test_block_added) { + DCHECK(deopt_block->GetSuccessors().Get(0) == pre_header); + } else { + DCHECK(deopt_block == pre_header); + } + HGraph* graph = header->GetGraph(); + HSuspendCheck* suspend_check = header->GetLoopInformation()->GetSuspendCheck(); // We may need to hoist null-check and array_length out of loop first. - if (!array_length->GetBlock()->Dominates(pre_header)) { + if (!array_length->GetBlock()->Dominates(deopt_block)) { + // array_length must be defined in the loop body. + DCHECK(header->GetLoopInformation()->Contains(*array_length->GetBlock())); + DCHECK(array_length->GetBlock() != header); + HInstruction* array = array_length->InputAt(0); HNullCheck* null_check = array->AsNullCheck(); if (null_check != nullptr) { array = null_check->InputAt(0); } - // We've already made sure array is defined before the loop when collecting + // We've already made sure the array is defined before the loop when collecting // array accesses for the loop. - DCHECK(array->GetBlock()->Dominates(pre_header)); - if (null_check != nullptr && !null_check->GetBlock()->Dominates(pre_header)) { + DCHECK(array->GetBlock()->Dominates(deopt_block)); + if (null_check != nullptr && !null_check->GetBlock()->Dominates(deopt_block)) { // Hoist null check out of loop with a deoptimization. HNullConstant* null_constant = graph->GetNullConstant(); HCondition* null_check_cond = new (graph->GetArena()) HEqual(array, null_constant); // TODO: for one dex_pc, share the same deoptimization slow path. HDeoptimize* null_check_deoptimize = new (graph->GetArena()) HDeoptimize(null_check_cond, suspend_check->GetDexPc()); - pre_header->InsertInstructionBefore(null_check_cond, pre_header->GetLastInstruction()); - pre_header->InsertInstructionBefore( - null_check_deoptimize, pre_header->GetLastInstruction()); + deopt_block->InsertInstructionBefore( + null_check_cond, deopt_block->GetLastInstruction()); + deopt_block->InsertInstructionBefore( + null_check_deoptimize, deopt_block->GetLastInstruction()); // Eliminate null check in the loop. null_check->ReplaceWith(array); null_check->GetBlock()->RemoveInstruction(null_check); null_check_deoptimize->CopyEnvironmentFromWithLoopPhiAdjustment( - suspend_check->GetEnvironment(), block); + suspend_check->GetEnvironment(), header); } - // Hoist array_length out of loop. - array_length->MoveBefore(pre_header->GetLastInstruction()); + + HArrayLength* new_array_length = new (graph->GetArena()) HArrayLength(array); + deopt_block->InsertInstructionBefore(new_array_length, deopt_block->GetLastInstruction()); + + if (loop_entry_test_block_added) { + // Replace array_length defined inside the loop body with a phi + // array_length_in_loop_body_if_needed. This is a synthetic phi so there is + // no vreg number for it. + HPhi* phi = new (graph->GetArena()) HPhi( + graph->GetArena(), kNoRegNumber, 2, Primitive::kPrimInt); + // Set to 0 if the loop body isn't entered. + phi->SetRawInputAt(0, graph->GetIntConstant(0)); + // Set to array.length if the loop body is entered. + phi->SetRawInputAt(1, new_array_length); + pre_header->AddPhi(phi); + array_length->ReplaceWith(phi); + // Make sure phi is only used after the loop body is entered. + if (kIsDebugBuild) { + for (HUseIterator<HInstruction*> it(phi->GetUses()); + !it.Done(); + it.Advance()) { + HInstruction* user = it.Current()->GetUser(); + DCHECK(GetLoopHeaderSuccesorInLoop()->Dominates(user->GetBlock())); + } + } + } else { + array_length->ReplaceWith(new_array_length); + } + + array_length->GetBlock()->RemoveInstruction(array_length); + // Use new_array_length for deopt. + array_length = new_array_length; } - HIntConstant* offset_instr = graph->GetIntConstant(offset); - HAdd* add = new (graph->GetArena()) HAdd(Primitive::kPrimInt, array_length, offset_instr); - HCondition* cond = new (graph->GetArena()) HGreaterThan(value, add); - HDeoptimize* deoptimize = new (graph->GetArena()) - HDeoptimize(cond, suspend_check->GetDexPc()); - pre_header->InsertInstructionBefore(add, pre_header->GetLastInstruction()); - pre_header->InsertInstructionBefore(cond, pre_header->GetLastInstruction()); - pre_header->InsertInstructionBefore(deoptimize, pre_header->GetLastInstruction()); - deoptimize->CopyEnvironmentFromWithLoopPhiAdjustment( - suspend_check->GetEnvironment(), block); + HInstruction* added = array_length; + if (offset != 0) { + HIntConstant* offset_instr = graph->GetIntConstant(offset); + added = new (graph->GetArena()) HAdd(Primitive::kPrimInt, array_length, offset_instr); + deopt_block->InsertInstructionBefore(added, deopt_block->GetLastInstruction()); + } + HCondition* cond = new (graph->GetArena()) HGreaterThan(value, added); + HDeoptimize* deopt = new (graph->GetArena()) HDeoptimize(cond, suspend_check->GetDexPc()); + deopt_block->InsertInstructionBefore(cond, deopt_block->GetLastInstruction()); + deopt_block->InsertInstructionBefore(deopt, deopt_block->GetLastInstruction()); + deopt->CopyEnvironmentFromWithLoopPhiAdjustment(suspend_check->GetEnvironment(), header); } - // Add deoptimizations in loop pre-header with the collected array access + // Adds deoptimizations in loop pre-header with the collected array access // data so that value ranges can be established in loop body. // Returns true if deoptimizations are successfully added, or if it's proven // it's not necessary. @@ -733,70 +1028,60 @@ class MonotonicValueRange : public ValueRange { return false; } + HBasicBlock* deopt_block; + bool loop_entry_test_block_added = false; bool is_constant_proven, is_length_proven; + + HInstruction* const_comparing_instruction; + int32_t const_compared_to; + HInstruction* array_length_comparing_instruction; + int32_t array_length_offset; if (increment_ == 1) { // Increasing from initial_ to end_. - int32_t offset = inclusive_ ? -offset_high - 1 : -offset_high; - if (CanAddDeoptimizationConstant(initial_, -offset_low, &is_constant_proven) && - CanAddDeoptimizationArrayLength(end_, array_length, offset, &is_length_proven)) { - if (!is_constant_proven) { - AddDeoptimizationConstant(initial_, -offset_low); - } - if (!is_length_proven) { - AddDeoptimizationArrayLength(end_, array_length, offset); + const_comparing_instruction = initial_; + const_compared_to = -offset_low; + array_length_comparing_instruction = end_; + array_length_offset = inclusive_ ? -offset_high - 1 : -offset_high; + } else { + const_comparing_instruction = end_; + const_compared_to = inclusive_ ? -offset_low : -offset_low - 1; + array_length_comparing_instruction = initial_; + array_length_offset = -offset_high - 1; + } + + if (CanAddDeoptimizationConstant(const_comparing_instruction, + const_compared_to, + &is_constant_proven) && + CanAddDeoptimizationArrayLength(array_length_comparing_instruction, + array_length, + array_length_offset, + &is_length_proven)) { + if (!is_constant_proven || !is_length_proven) { + deopt_block = TransformLoopForDeoptimizationIfNeeded(); + loop_entry_test_block_added = (deopt_block != pre_header); + if (loop_entry_test_block_added) { + // Loop body may be entered. + AddLoopBodyEntryTest(); } - return true; } - } else if (increment_ == -1) { - // Decreasing from initial_ to end_. - int32_t constant = inclusive_ ? -offset_low : -offset_low - 1; - if (CanAddDeoptimizationConstant(end_, constant, &is_constant_proven) && - CanAddDeoptimizationArrayLength( - initial_, array_length, -offset_high - 1, &is_length_proven)) { - if (!is_constant_proven) { - AddDeoptimizationConstant(end_, constant); - } - if (!is_length_proven) { - AddDeoptimizationArrayLength(initial_, array_length, -offset_high - 1); - } - return true; + if (!is_constant_proven) { + AddDeoptimizationConstant(const_comparing_instruction, + const_compared_to, + deopt_block, + loop_entry_test_block_added); + } + if (!is_length_proven) { + AddDeoptimizationArrayLength(array_length_comparing_instruction, + array_length, + array_length_offset, + deopt_block, + loop_entry_test_block_added); } + return true; } return false; } - // Try to add HDeoptimize's in the loop pre-header first to narrow this range. - ValueRange* NarrowWithDeoptimization() { - if (increment_ != 1 && increment_ != -1) { - // TODO: possibly handle overflow/underflow issues with deoptimization. - return this; - } - - if (end_ == nullptr) { - // No full info to add deoptimization. - return this; - } - - ArrayAccessInsideLoopFinder finder(induction_variable_); - - if (!finder.HasFoundArrayLength()) { - // No array access was found inside the loop that can benefit - // from deoptimization. - return this; - } - - if (!AddDeoptimization(finder)) { - return this; - } - - // After added deoptimizations, induction variable fits in - // [-offset_low, array.length-1-offset_high], adjusted with collected offsets. - ValueBound lower = ValueBound(0, -finder.GetOffsetLow()); - ValueBound upper = ValueBound(finder.GetFoundArrayLength(), -1 - finder.GetOffsetHigh()); - // We've narrowed the range after added deoptimizations. - return new (GetAllocator()) ValueRange(GetAllocator(), lower, upper); - } - private: HPhi* const induction_variable_; // Induction variable for this monotonic value range. HInstruction* const initial_; // Initial value. @@ -819,12 +1104,17 @@ class BCEVisitor : public HGraphVisitor { // it's likely some AIOOBE will be thrown. static constexpr int32_t kMaxConstantForAddingDeoptimize = INT_MAX - 1024 * 1024; + // Added blocks for loop body entry test. + bool IsAddedBlock(HBasicBlock* block) const { + return block->GetBlockId() >= initial_block_size_; + } + explicit BCEVisitor(HGraph* graph) - : HGraphVisitor(graph), - maps_(graph->GetBlocks().Size()), - need_to_revisit_block_(false) {} + : HGraphVisitor(graph), maps_(graph->GetBlocks().Size()), + need_to_revisit_block_(false), initial_block_size_(graph->GetBlocks().Size()) {} void VisitBasicBlock(HBasicBlock* block) OVERRIDE { + DCHECK(!IsAddedBlock(block)); first_constant_index_bounds_check_map_.clear(); HGraphVisitor::VisitBasicBlock(block); if (need_to_revisit_block_) { @@ -839,6 +1129,10 @@ class BCEVisitor : public HGraphVisitor { private: // Return the map of proven value ranges at the beginning of a basic block. ArenaSafeMap<int, ValueRange*>* GetValueRangeMap(HBasicBlock* basic_block) { + if (IsAddedBlock(basic_block)) { + // Added blocks don't keep value ranges. + return nullptr; + } int block_id = basic_block->GetBlockId(); if (maps_.at(block_id) == nullptr) { std::unique_ptr<ArenaSafeMap<int, ValueRange*>> map( @@ -853,8 +1147,12 @@ class BCEVisitor : public HGraphVisitor { ValueRange* LookupValueRange(HInstruction* instruction, HBasicBlock* basic_block) { while (basic_block != nullptr) { ArenaSafeMap<int, ValueRange*>* map = GetValueRangeMap(basic_block); - if (map->find(instruction->GetId()) != map->end()) { - return map->Get(instruction->GetId()); + if (map != nullptr) { + if (map->find(instruction->GetId()) != map->end()) { + return map->Get(instruction->GetId()); + } + } else { + DCHECK(IsAddedBlock(basic_block)); } basic_block = basic_block->GetDominator(); } @@ -971,7 +1269,7 @@ class BCEVisitor : public HGraphVisitor { if (left_range != nullptr) { left_monotonic_range = left_range->AsMonotonicValueRange(); if (left_monotonic_range != nullptr) { - HBasicBlock* loop_head = left_monotonic_range->GetLoopHead(); + HBasicBlock* loop_head = left_monotonic_range->GetLoopHeader(); if (instruction->GetBlock() != loop_head) { // For monotonic value range, don't handle `instruction` // if it's not defined in the loop header. @@ -1013,7 +1311,7 @@ class BCEVisitor : public HGraphVisitor { // Update the info for monotonic value range. if (left_monotonic_range->GetInductionVariable() == left && left_monotonic_range->GetIncrement() < 0 && - block == left_monotonic_range->GetLoopHead() && + block == left_monotonic_range->GetLoopHeader() && instruction->IfFalseSuccessor()->GetLoopInformation() == block->GetLoopInformation()) { left_monotonic_range->SetEnd(right); left_monotonic_range->SetInclusive(cond == kCondLT); @@ -1047,7 +1345,7 @@ class BCEVisitor : public HGraphVisitor { // Update the info for monotonic value range. if (left_monotonic_range->GetInductionVariable() == left && left_monotonic_range->GetIncrement() > 0 && - block == left_monotonic_range->GetLoopHead() && + block == left_monotonic_range->GetLoopHeader() && instruction->IfFalseSuccessor()->GetLoopInformation() == block->GetLoopInformation()) { left_monotonic_range->SetEnd(right); left_monotonic_range->SetInclusive(cond == kCondGT); @@ -1083,7 +1381,16 @@ class BCEVisitor : public HGraphVisitor { HBasicBlock* block = bounds_check->GetBlock(); HInstruction* index = bounds_check->InputAt(0); HInstruction* array_length = bounds_check->InputAt(1); - DCHECK(array_length->IsIntConstant() || array_length->IsArrayLength()); + DCHECK(array_length->IsIntConstant() || + array_length->IsArrayLength() || + array_length->IsPhi()); + + if (array_length->IsPhi()) { + // Input 1 of the phi contains the real array.length once the loop body is + // entered. That value will be used for bound analysis. The graph is still + // strickly in SSA form. + array_length = array_length->AsPhi()->InputAt(1)->AsArrayLength(); + } if (!index->IsIntConstant()) { ValueRange* index_range = LookupValueRange(index, block); @@ -1238,25 +1545,26 @@ class BCEVisitor : public HGraphVisitor { } if (left_range->IsMonotonicValueRange() && - block == left_range->AsMonotonicValueRange()->GetLoopHead()) { + block == left_range->AsMonotonicValueRange()->GetLoopHeader()) { // The comparison is for an induction variable in the loop header. DCHECK(left == left_range->AsMonotonicValueRange()->GetInductionVariable()); - HBasicBlock* loop_body_successor; - if (LIKELY(block->GetLoopInformation()-> - Contains(*instruction->IfFalseSuccessor()))) { - loop_body_successor = instruction->IfFalseSuccessor(); - } else { - loop_body_successor = instruction->IfTrueSuccessor(); + HBasicBlock* loop_body_successor = + left_range->AsMonotonicValueRange()->GetLoopHeaderSuccesorInLoop(); + if (loop_body_successor == nullptr) { + // In case it's some strange loop structure. + return; } ValueRange* new_left_range = LookupValueRange(left, loop_body_successor); - if (new_left_range == left_range) { + if ((new_left_range == left_range) || + // Range narrowed with deoptimization is usually more useful than + // a constant range. + new_left_range->IsConstantValueRange()) { // We are not successful in narrowing the monotonic value range to // a regular value range. Try using deoptimization. new_left_range = left_range->AsMonotonicValueRange()-> NarrowWithDeoptimization(); if (new_left_range != left_range) { - GetValueRangeMap(instruction->IfFalseSuccessor())-> - Overwrite(left->GetId(), new_left_range); + GetValueRangeMap(loop_body_successor)->Overwrite(left->GetId(), new_left_range); } } } @@ -1511,6 +1819,9 @@ class BCEVisitor : public HGraphVisitor { // eliminate those bounds checks. bool need_to_revisit_block_; + // Initial number of blocks. + int32_t initial_block_size_; + DISALLOW_COPY_AND_ASSIGN(BCEVisitor); }; @@ -1527,7 +1838,22 @@ void BoundsCheckElimination::Run() { // value can be narrowed further down in the dominator tree. // // TODO: only visit blocks that dominate some array accesses. - visitor.VisitReversePostOrder(); + HBasicBlock* last_visited_block = nullptr; + for (HReversePostOrderIterator it(*graph_); !it.Done(); it.Advance()) { + HBasicBlock* current = it.Current(); + if (current == last_visited_block) { + // We may insert blocks into the reverse post order list when processing + // a loop header. Don't process it again. + DCHECK(current->IsLoopHeader()); + continue; + } + if (visitor.IsAddedBlock(current)) { + // Skip added blocks. Their effects are already taken care of. + continue; + } + visitor.VisitBasicBlock(current); + last_visited_block = current; + } } } // namespace art diff --git a/compiler/optimizing/bounds_check_elimination_test.cc b/compiler/optimizing/bounds_check_elimination_test.cc index e383ec664b..4701bddd48 100644 --- a/compiler/optimizing/bounds_check_elimination_test.cc +++ b/compiler/optimizing/bounds_check_elimination_test.cc @@ -440,22 +440,16 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination1) { HInstruction* bounds_check = nullptr; HGraph* graph = BuildSSAGraph1(&allocator, &bounds_check, 0, 1); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); + RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination(graph); bounds_check_elimination.Run(); - ASSERT_FALSE(IsRemoved(bounds_check)); - - // This time add gvn. Need gvn to eliminate the second - // HArrayLength which uses the null check as its input. - graph = BuildSSAGraph1(&allocator, &bounds_check, 0, 1); - graph->BuildDominatorTree(); - RunSimplifierAndGvn(graph); - BoundsCheckElimination bounds_check_elimination_after_gvn(graph); - bounds_check_elimination_after_gvn.Run(); ASSERT_TRUE(IsRemoved(bounds_check)); // for (int i=1; i<array.length; i++) { array[i] = 10; // Can eliminate. } graph = BuildSSAGraph1(&allocator, &bounds_check, 1, 1); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_initial_1(graph); bounds_check_elimination_with_initial_1.Run(); @@ -464,6 +458,7 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination1) { // for (int i=-1; i<array.length; i++) { array[i] = 10; // Can't eliminate. } graph = BuildSSAGraph1(&allocator, &bounds_check, -1, 1); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_initial_minus_1(graph); bounds_check_elimination_with_initial_minus_1.Run(); @@ -472,6 +467,7 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination1) { // for (int i=0; i<=array.length; i++) { array[i] = 10; // Can't eliminate. } graph = BuildSSAGraph1(&allocator, &bounds_check, 0, 1, kCondGT); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_greater_than(graph); bounds_check_elimination_with_greater_than.Run(); @@ -481,6 +477,7 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination1) { // array[i] = 10; // Can't eliminate due to overflow concern. } graph = BuildSSAGraph1(&allocator, &bounds_check, 0, 2); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_increment_2(graph); bounds_check_elimination_with_increment_2.Run(); @@ -489,6 +486,7 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination1) { // for (int i=1; i<array.length; i += 2) { array[i] = 10; // Can eliminate. } graph = BuildSSAGraph1(&allocator, &bounds_check, 1, 2); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_increment_2_from_1(graph); bounds_check_elimination_with_increment_2_from_1.Run(); @@ -579,22 +577,16 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination2) { HInstruction* bounds_check = nullptr; HGraph* graph = BuildSSAGraph2(&allocator, &bounds_check, 0); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); + RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination(graph); bounds_check_elimination.Run(); - ASSERT_FALSE(IsRemoved(bounds_check)); - - // This time add gvn. Need gvn to eliminate the second - // HArrayLength which uses the null check as its input. - graph = BuildSSAGraph2(&allocator, &bounds_check, 0); - graph->BuildDominatorTree(); - RunSimplifierAndGvn(graph); - BoundsCheckElimination bounds_check_elimination_after_gvn(graph); - bounds_check_elimination_after_gvn.Run(); ASSERT_TRUE(IsRemoved(bounds_check)); // for (int i=array.length; i>1; i--) { array[i-1] = 10; // Can eliminate. } graph = BuildSSAGraph2(&allocator, &bounds_check, 1); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_initial_1(graph); bounds_check_elimination_with_initial_1.Run(); @@ -603,6 +595,7 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination2) { // for (int i=array.length; i>-1; i--) { array[i-1] = 10; // Can't eliminate. } graph = BuildSSAGraph2(&allocator, &bounds_check, -1); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_initial_minus_1(graph); bounds_check_elimination_with_initial_minus_1.Run(); @@ -611,6 +604,7 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination2) { // for (int i=array.length; i>=0; i--) { array[i-1] = 10; // Can't eliminate. } graph = BuildSSAGraph2(&allocator, &bounds_check, 0, -1, kCondLT); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_less_than(graph); bounds_check_elimination_with_less_than.Run(); @@ -619,6 +613,7 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination2) { // for (int i=array.length; i>0; i-=2) { array[i-1] = 10; // Can eliminate. } graph = BuildSSAGraph2(&allocator, &bounds_check, 0, -2); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_increment_minus_2(graph); bounds_check_elimination_increment_minus_2.Run(); @@ -710,15 +705,17 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination3) { HInstruction* bounds_check = nullptr; HGraph* graph = BuildSSAGraph3(&allocator, &bounds_check, 0, 1, kCondGE); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); - BoundsCheckElimination bounds_check_elimination_after_gvn(graph); - bounds_check_elimination_after_gvn.Run(); + BoundsCheckElimination bounds_check_elimination(graph); + bounds_check_elimination.Run(); ASSERT_TRUE(IsRemoved(bounds_check)); // int[] array = new int[10]; // for (int i=1; i<10; i++) { array[i] = 10; // Can eliminate. } graph = BuildSSAGraph3(&allocator, &bounds_check, 1, 1, kCondGE); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_initial_1(graph); bounds_check_elimination_with_initial_1.Run(); @@ -728,6 +725,7 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination3) { // for (int i=0; i<=10; i++) { array[i] = 10; // Can't eliminate. } graph = BuildSSAGraph3(&allocator, &bounds_check, 0, 1, kCondGT); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_greater_than(graph); bounds_check_elimination_with_greater_than.Run(); @@ -737,6 +735,7 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination3) { // for (int i=1; i<10; i+=8) { array[i] = 10; // Can eliminate. } graph = BuildSSAGraph3(&allocator, &bounds_check, 1, 8, kCondGE); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_increment_8(graph); bounds_check_elimination_increment_8.Run(); @@ -828,22 +827,16 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination4) { HInstruction* bounds_check = nullptr; HGraph* graph = BuildSSAGraph4(&allocator, &bounds_check, 0); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); + RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination(graph); bounds_check_elimination.Run(); - ASSERT_FALSE(IsRemoved(bounds_check)); - - // This time add gvn. Need gvn to eliminate the second - // HArrayLength which uses the null check as its input. - graph = BuildSSAGraph4(&allocator, &bounds_check, 0); - graph->BuildDominatorTree(); - RunSimplifierAndGvn(graph); - BoundsCheckElimination bounds_check_elimination_after_gvn(graph); - bounds_check_elimination_after_gvn.Run(); ASSERT_TRUE(IsRemoved(bounds_check)); // for (int i=1; i<array.length; i++) { array[array.length-i-1] = 10; // Can eliminate. } graph = BuildSSAGraph4(&allocator, &bounds_check, 1); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_initial_1(graph); bounds_check_elimination_with_initial_1.Run(); @@ -852,6 +845,7 @@ TEST(BoundsCheckEliminationTest, LoopArrayBoundsElimination4) { // for (int i=0; i<=array.length; i++) { array[array.length-i] = 10; // Can't eliminate. } graph = BuildSSAGraph4(&allocator, &bounds_check, 0, kCondGT); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); BoundsCheckElimination bounds_check_elimination_with_greater_than(graph); bounds_check_elimination_with_greater_than.Run(); @@ -1027,6 +1021,7 @@ TEST(BoundsCheckEliminationTest, BubbleSortArrayBoundsElimination) { outer_body_add->AddSuccessor(outer_header); graph->BuildDominatorTree(); + graph->AnalyzeNaturalLoops(); RunSimplifierAndGvn(graph); // gvn should remove the same bounds check. ASSERT_FALSE(IsRemoved(bounds_check1)); diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc index cd91d2c87b..4baa05c80c 100644 --- a/compiler/optimizing/nodes.cc +++ b/compiler/optimizing/nodes.cc @@ -1510,6 +1510,81 @@ void HGraph::InlineInto(HGraph* outer_graph, HInvoke* invoke) { invoke->GetBlock()->RemoveInstruction(invoke); } +/* + * Loop will be transformed to: + * old_pre_header + * | + * if_block + * / \ + * dummy_block deopt_block + * \ / + * new_pre_header + * | + * header + */ +void HGraph::TransformLoopHeaderForBCE(HBasicBlock* header) { + DCHECK(header->IsLoopHeader()); + HBasicBlock* pre_header = header->GetDominator(); + + // Need this to avoid critical edge. + HBasicBlock* if_block = new (arena_) HBasicBlock(this, header->GetDexPc()); + // Need this to avoid critical edge. + HBasicBlock* dummy_block = new (arena_) HBasicBlock(this, header->GetDexPc()); + HBasicBlock* deopt_block = new (arena_) HBasicBlock(this, header->GetDexPc()); + HBasicBlock* new_pre_header = new (arena_) HBasicBlock(this, header->GetDexPc()); + AddBlock(if_block); + AddBlock(dummy_block); + AddBlock(deopt_block); + AddBlock(new_pre_header); + + header->ReplacePredecessor(pre_header, new_pre_header); + pre_header->successors_.Reset(); + pre_header->dominated_blocks_.Reset(); + + pre_header->AddSuccessor(if_block); + if_block->AddSuccessor(dummy_block); // True successor + if_block->AddSuccessor(deopt_block); // False successor + dummy_block->AddSuccessor(new_pre_header); + deopt_block->AddSuccessor(new_pre_header); + + pre_header->dominated_blocks_.Add(if_block); + if_block->SetDominator(pre_header); + if_block->dominated_blocks_.Add(dummy_block); + dummy_block->SetDominator(if_block); + if_block->dominated_blocks_.Add(deopt_block); + deopt_block->SetDominator(if_block); + if_block->dominated_blocks_.Add(new_pre_header); + new_pre_header->SetDominator(if_block); + new_pre_header->dominated_blocks_.Add(header); + header->SetDominator(new_pre_header); + + size_t index_of_header = 0; + while (reverse_post_order_.Get(index_of_header) != header) { + index_of_header++; + } + MakeRoomFor(&reverse_post_order_, 4, index_of_header - 1); + reverse_post_order_.Put(index_of_header++, if_block); + reverse_post_order_.Put(index_of_header++, dummy_block); + reverse_post_order_.Put(index_of_header++, deopt_block); + reverse_post_order_.Put(index_of_header++, new_pre_header); + + HLoopInformation* info = pre_header->GetLoopInformation(); + if (info != nullptr) { + if_block->SetLoopInformation(info); + dummy_block->SetLoopInformation(info); + deopt_block->SetLoopInformation(info); + new_pre_header->SetLoopInformation(info); + for (HLoopInformationOutwardIterator loop_it(*pre_header); + !loop_it.Done(); + loop_it.Advance()) { + loop_it.Current()->Add(if_block); + loop_it.Current()->Add(dummy_block); + loop_it.Current()->Add(deopt_block); + loop_it.Current()->Add(new_pre_header); + } + } +} + std::ostream& operator<<(std::ostream& os, const ReferenceTypeInfo& rhs) { ScopedObjectAccess soa(Thread::Current()); os << "[" diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h index 5f128a7072..126b3b9879 100644 --- a/compiler/optimizing/nodes.h +++ b/compiler/optimizing/nodes.h @@ -195,6 +195,10 @@ class HGraph : public ArenaObject<kArenaAllocMisc> { // Inline this graph in `outer_graph`, replacing the given `invoke` instruction. void InlineInto(HGraph* outer_graph, HInvoke* invoke); + // Need to add a couple of blocks to test if the loop body is entered and + // put deoptimization instructions, etc. + void TransformLoopHeaderForBCE(HBasicBlock* header); + // Removes `block` from the graph. void DeleteDeadBlock(HBasicBlock* block); @@ -4264,6 +4268,39 @@ class HBlocksInLoopIterator : public ValueObject { DISALLOW_COPY_AND_ASSIGN(HBlocksInLoopIterator); }; +// Iterator over the blocks that art part of the loop. Includes blocks part +// of an inner loop. The order in which the blocks are iterated is reverse +// post order. +class HBlocksInLoopReversePostOrderIterator : public ValueObject { + public: + explicit HBlocksInLoopReversePostOrderIterator(const HLoopInformation& info) + : blocks_in_loop_(info.GetBlocks()), + blocks_(info.GetHeader()->GetGraph()->GetReversePostOrder()), + index_(0) { + if (!blocks_in_loop_.IsBitSet(blocks_.Get(index_)->GetBlockId())) { + Advance(); + } + } + + bool Done() const { return index_ == blocks_.Size(); } + HBasicBlock* Current() const { return blocks_.Get(index_); } + void Advance() { + ++index_; + for (size_t e = blocks_.Size(); index_ < e; ++index_) { + if (blocks_in_loop_.IsBitSet(blocks_.Get(index_)->GetBlockId())) { + break; + } + } + } + + private: + const BitVector& blocks_in_loop_; + const GrowableArray<HBasicBlock*>& blocks_; + size_t index_; + + DISALLOW_COPY_AND_ASSIGN(HBlocksInLoopReversePostOrderIterator); +}; + inline int64_t Int64FromConstant(HConstant* constant) { DCHECK(constant->IsIntConstant() || constant->IsLongConstant()); return constant->IsIntConstant() ? constant->AsIntConstant()->GetValue() |