ART vectorizer.

Rationale:
Make SIMD great again with a retargetable and easily extendable vectorizer.

Provides a full x86/x86_64 and a proof-of-concept ARM implementation. Sample
improvement (without any perf tuning yet) for Linpack on x86 is about 20% to 50%.

Test: test-art-host, test-art-target (angler)
Bug: 34083438, 30933338

Change-Id: Ifb77a0f25f690a87cd65bf3d5e9f6be7ea71d6c1

1 files changed, 60 insertions, 0 deletions

diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index caada8bccb..5617e4bfcb 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -2340,6 +2340,66 @@ void HGraph::TransformLoopHeaderForBCE(HBasicBlock* header) {
       new_pre_header, old_pre_header, /* replace_if_back_edge */ false);
 }
 
+HBasicBlock* HGraph::TransformLoopForVectorization(HBasicBlock* header,
+                                                   HBasicBlock* body,
+                                                   HBasicBlock* exit) {
+  DCHECK(header->IsLoopHeader());
+  HLoopInformation* loop = header->GetLoopInformation();
+
+  // Add new loop blocks.
+  HBasicBlock* new_pre_header = new (arena_) HBasicBlock(this, header->GetDexPc());
+  HBasicBlock* new_header = new (arena_) HBasicBlock(this, header->GetDexPc());
+  HBasicBlock* new_body = new (arena_) HBasicBlock(this, header->GetDexPc());
+  AddBlock(new_pre_header);
+  AddBlock(new_header);
+  AddBlock(new_body);
+
+  // Set up control flow.
+  header->ReplaceSuccessor(exit, new_pre_header);
+  new_pre_header->AddSuccessor(new_header);
+  new_header->AddSuccessor(exit);
+  new_header->AddSuccessor(new_body);
+  new_body->AddSuccessor(new_header);
+
+  // Set up dominators.
+  header->ReplaceDominatedBlock(exit, new_pre_header);
+  new_pre_header->SetDominator(header);
+  new_pre_header->dominated_blocks_.push_back(new_header);
+  new_header->SetDominator(new_pre_header);
+  new_header->dominated_blocks_.push_back(new_body);
+  new_body->SetDominator(new_header);
+  new_header->dominated_blocks_.push_back(exit);
+  exit->SetDominator(new_header);
+
+  // Fix reverse post order.
+  size_t index_of_header = IndexOfElement(reverse_post_order_, header);
+  MakeRoomFor(&reverse_post_order_, 2, index_of_header);
+  reverse_post_order_[++index_of_header] = new_pre_header;
+  reverse_post_order_[++index_of_header] = new_header;
+  size_t index_of_body = IndexOfElement(reverse_post_order_, body);
+  MakeRoomFor(&reverse_post_order_, 1, index_of_body - 1);
+  reverse_post_order_[index_of_body] = new_body;
+
+  // Add gotos and suspend check (client must add conditional in header and copy environment).
+  new_pre_header->AddInstruction(new (arena_) HGoto());
+  HSuspendCheck* suspend_check = new (arena_) HSuspendCheck(header->GetDexPc());
+  new_header->AddInstruction(suspend_check);
+  new_body->AddInstruction(new (arena_) HGoto());
+
+  // Update loop information.
+  new_header->AddBackEdge(new_body);
+  new_header->GetLoopInformation()->SetSuspendCheck(suspend_check);
+  new_header->GetLoopInformation()->Populate();
+  new_pre_header->SetLoopInformation(loop->GetPreHeader()->GetLoopInformation());  // outward
+  HLoopInformationOutwardIterator it(*new_header);
+  for (it.Advance(); !it.Done(); it.Advance()) {
+    it.Current()->Add(new_pre_header);
+    it.Current()->Add(new_header);
+    it.Current()->Add(new_body);
+  }
+  return new_pre_header;
+}
+
 static void CheckAgainstUpperBound(ReferenceTypeInfo rti, ReferenceTypeInfo upper_bound_rti)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   if (rti.IsValid()) {