Index: src/hydrogen-infer-representation.cc |
diff --git a/src/hydrogen-infer-representation.cc b/src/hydrogen-infer-representation.cc |
deleted file mode 100644 |
index 6687aefed8fa7a538858e6060c3065cda4d05d51..0000000000000000000000000000000000000000 |
--- a/src/hydrogen-infer-representation.cc |
+++ /dev/null |
@@ -1,162 +0,0 @@ |
-// Copyright 2013 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/hydrogen-infer-representation.h" |
- |
-namespace v8 { |
-namespace internal { |
- |
-void HInferRepresentationPhase::AddToWorklist(HValue* current) { |
- if (current->representation().IsTagged()) return; |
- if (!current->CheckFlag(HValue::kFlexibleRepresentation)) return; |
- if (in_worklist_.Contains(current->id())) return; |
- worklist_.Add(current, zone()); |
- in_worklist_.Add(current->id()); |
-} |
- |
- |
-void HInferRepresentationPhase::Run() { |
- // (1) Initialize bit vectors and count real uses. Each phi gets a |
- // bit-vector of length <number of phis>. |
- const ZoneList<HPhi*>* phi_list = graph()->phi_list(); |
- int phi_count = phi_list->length(); |
- ZoneList<BitVector*> connected_phis(phi_count, zone()); |
- for (int i = 0; i < phi_count; ++i) { |
- phi_list->at(i)->InitRealUses(i); |
- BitVector* connected_set = new(zone()) BitVector(phi_count, zone()); |
- connected_set->Add(i); |
- connected_phis.Add(connected_set, zone()); |
- } |
- |
- // (2) Do a fixed point iteration to find the set of connected phis. A |
- // phi is connected to another phi if its value is used either directly or |
- // indirectly through a transitive closure of the def-use relation. |
- bool change = true; |
- while (change) { |
- change = false; |
- // We normally have far more "forward edges" than "backward edges", |
- // so we terminate faster when we walk backwards. |
- for (int i = phi_count - 1; i >= 0; --i) { |
- HPhi* phi = phi_list->at(i); |
- for (HUseIterator it(phi->uses()); !it.Done(); it.Advance()) { |
- HValue* use = it.value(); |
- if (use->IsPhi()) { |
- int id = HPhi::cast(use)->phi_id(); |
- if (connected_phis[i]->UnionIsChanged(*connected_phis[id])) |
- change = true; |
- } |
- } |
- } |
- } |
- |
- // Set truncation flags for groups of connected phis. This is a conservative |
- // approximation; the flag will be properly re-computed after representations |
- // have been determined. |
- if (phi_count > 0) { |
- BitVector done(phi_count, zone()); |
- for (int i = 0; i < phi_count; ++i) { |
- if (done.Contains(i)) continue; |
- |
- // Check if all uses of all connected phis in this group are truncating. |
- bool all_uses_everywhere_truncating_int32 = true; |
- bool all_uses_everywhere_truncating_smi = true; |
- for (BitVector::Iterator it(connected_phis[i]); |
- !it.Done(); |
- it.Advance()) { |
- int index = it.Current(); |
- all_uses_everywhere_truncating_int32 &= |
- phi_list->at(index)->CheckFlag(HInstruction::kTruncatingToInt32); |
- all_uses_everywhere_truncating_smi &= |
- phi_list->at(index)->CheckFlag(HInstruction::kTruncatingToSmi); |
- done.Add(index); |
- } |
- |
- if (!all_uses_everywhere_truncating_int32) { |
- // Clear truncation flag of this group of connected phis. |
- for (BitVector::Iterator it(connected_phis[i]); |
- !it.Done(); |
- it.Advance()) { |
- int index = it.Current(); |
- phi_list->at(index)->ClearFlag(HInstruction::kTruncatingToInt32); |
- } |
- } |
- if (!all_uses_everywhere_truncating_smi) { |
- // Clear truncation flag of this group of connected phis. |
- for (BitVector::Iterator it(connected_phis[i]); |
- !it.Done(); |
- it.Advance()) { |
- int index = it.Current(); |
- phi_list->at(index)->ClearFlag(HInstruction::kTruncatingToSmi); |
- } |
- } |
- } |
- } |
- |
- // Simplify constant phi inputs where possible. |
- // This step uses kTruncatingToInt32 flags of phis. |
- for (int i = 0; i < phi_count; ++i) { |
- phi_list->at(i)->SimplifyConstantInputs(); |
- } |
- |
- // Use the phi reachability information from step 2 to |
- // sum up the non-phi use counts of all connected phis. |
- for (int i = 0; i < phi_count; ++i) { |
- HPhi* phi = phi_list->at(i); |
- for (BitVector::Iterator it(connected_phis[i]); |
- !it.Done(); |
- it.Advance()) { |
- int index = it.Current(); |
- HPhi* it_use = phi_list->at(index); |
- if (index != i) phi->AddNonPhiUsesFrom(it_use); // Don't count twice. |
- } |
- } |
- |
- // Initialize work list |
- for (int i = 0; i < graph()->blocks()->length(); ++i) { |
- HBasicBlock* block = graph()->blocks()->at(i); |
- const ZoneList<HPhi*>* phis = block->phis(); |
- for (int j = 0; j < phis->length(); ++j) { |
- AddToWorklist(phis->at(j)); |
- } |
- |
- for (HInstructionIterator it(block); !it.Done(); it.Advance()) { |
- HInstruction* current = it.Current(); |
- AddToWorklist(current); |
- } |
- } |
- |
- // Do a fixed point iteration, trying to improve representations |
- while (!worklist_.is_empty()) { |
- HValue* current = worklist_.RemoveLast(); |
- current->InferRepresentation(this); |
- in_worklist_.Remove(current->id()); |
- } |
- |
- // Lastly: any instruction that we don't have representation information |
- // for defaults to Tagged. |
- for (int i = 0; i < graph()->blocks()->length(); ++i) { |
- HBasicBlock* block = graph()->blocks()->at(i); |
- const ZoneList<HPhi*>* phis = block->phis(); |
- for (int j = 0; j < phis->length(); ++j) { |
- HPhi* phi = phis->at(j); |
- if (phi->representation().IsNone()) { |
- phi->ChangeRepresentation(Representation::Tagged()); |
- } |
- } |
- for (HInstructionIterator it(block); !it.Done(); it.Advance()) { |
- HInstruction* current = it.Current(); |
- if (current->representation().IsNone() && |
- current->CheckFlag(HInstruction::kFlexibleRepresentation)) { |
- if (current->CheckFlag(HInstruction::kCannotBeTagged)) { |
- current->ChangeRepresentation(Representation::Double()); |
- } else { |
- current->ChangeRepresentation(Representation::Tagged()); |
- } |
- } |
- } |
- } |
-} |
- |
-} // namespace internal |
-} // namespace v8 |