commit ed59619b370ef23ffbb25d1d01f615e60a9262b6
author David Brazdil <dbrazdil@google.com> Fri Jan 23 10:39:45 2015 +0000
committer David Brazdil <dbrazdil@google.com> Mon Jan 26 16:13:57 2015 +0000
tree 6c93bb6ceff95f7aaf232825e050eecc05c7282d
parent f90eec005997f98c1a9f874fbbf68414e5f9c766

Optimizing: Speed up HEnvironment use removal

Removal of use records from HEnvironment vregs involved iterating over
potentially large linked lists which made compilation of huge methods
very slow. This patch turns use lists into doubly-linked lists, stores
pointers to the relevant nodes inside HEnvironment and subsequently
turns the removals into constant-time operations.

Change-Id: I0e1d4d782fd624e7b8075af75d4adf0a0634a1ee

compiler/optimizing/ssa_builder.cc

diff --git a/compiler/optimizing/ssa_builder.cc b/compiler/optimizing/ssa_builder.cc
index edfafcd..4f9c3b8 100644
--- a/compiler/optimizing/ssa_builder.cc
+++ b/compiler/optimizing/ssa_builder.cc
@@ -68,7 +68,7 @@
 }
 
 HInstruction* SsaBuilder::ValueOfLocal(HBasicBlock* block, size_t local) {
-  return GetLocalsFor(block)->Get(local);
+  return GetLocalsFor(block)->GetInstructionAt(local);
 }
 
 void SsaBuilder::VisitBasicBlock(HBasicBlock* block) {
@@ -85,7 +85,7 @@
         HPhi* phi = new (GetGraph()->GetArena()) HPhi(
             GetGraph()->GetArena(), local, 0, Primitive::kPrimVoid);
         block->AddPhi(phi);
-        current_locals_->Put(local, phi);
+        current_locals_->SetRawEnvAt(local, phi);
       }
     }
     // Save the loop header so that the last phase of the analysis knows which
@@ -125,7 +125,7 @@
         block->AddPhi(phi);
         value = phi;
       }
-      current_locals_->Put(local, value);
+      current_locals_->SetRawEnvAt(local, value);
     }
   }
 
@@ -235,7 +235,7 @@
 }
 
 void SsaBuilder::VisitLoadLocal(HLoadLocal* load) {
-  HInstruction* value = current_locals_->Get(load->GetLocal()->GetRegNumber());
+  HInstruction* value = current_locals_->GetInstructionAt(load->GetLocal()->GetRegNumber());
   if (load->GetType() != value->GetType()
       && (load->GetType() == Primitive::kPrimFloat || load->GetType() == Primitive::kPrimDouble)) {
     // If the operation requests a specific type, we make sure its input is of that type.
@@ -246,7 +246,7 @@
 }
 
 void SsaBuilder::VisitStoreLocal(HStoreLocal* store) {
-  current_locals_->Put(store->GetLocal()->GetRegNumber(), store->InputAt(1));
+  current_locals_->SetRawEnvAt(store->GetLocal()->GetRegNumber(), store->InputAt(1));
   store->GetBlock()->RemoveInstruction(store);
 }
 
@@ -256,7 +256,7 @@
   }
   HEnvironment* environment = new (GetGraph()->GetArena()) HEnvironment(
       GetGraph()->GetArena(), current_locals_->Size());
-  environment->Populate(*current_locals_);
+  environment->CopyFrom(current_locals_);
   instruction->SetEnvironment(environment);
 }