Add a Transform to SSA phase to the optimizing compiler.

Change-Id: Ia9700756a0396d797a00b529896487d52c989329

1 files changed, 71 insertions, 0 deletions

diff --git a/compiler/optimizing/ssa_builder.h b/compiler/optimizing/ssa_builder.h
new file mode 100644
index 0000000..b6c6c0b
--- /dev/null
+++ b/compiler/optimizing/ssa_builder.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_OPTIMIZING_SSA_BUILDER_H_
+#define ART_COMPILER_OPTIMIZING_SSA_BUILDER_H_
+
+#include "nodes.h"
+
+namespace art {
+
+static constexpr int kDefaultNumberOfLoops = 2;
+
+class SsaBuilder : public HGraphVisitor {
+ public:
+  explicit SsaBuilder(HGraph* graph)
+      : HGraphVisitor(graph),
+        current_locals_(nullptr),
+        loop_headers_(graph->GetArena(), kDefaultNumberOfLoops),
+        locals_for_(graph->GetArena(), graph->GetBlocks()->Size()) {
+    locals_for_.SetSize(graph->GetBlocks()->Size());
+  }
+
+  void BuildSsa();
+
+  GrowableArray<HInstruction*>* GetLocalsFor(HBasicBlock* block) {
+    HEnvironment* env = locals_for_.Get(block->GetBlockId());
+    if (env == nullptr) {
+      env = new (GetGraph()->GetArena()) HEnvironment(
+          GetGraph()->GetArena(), GetGraph()->GetNumberOfVRegs());
+      locals_for_.Put(block->GetBlockId(), env);
+    }
+    return env->GetVRegs();
+  }
+
+  HInstruction* ValueOfLocal(HBasicBlock* block, size_t local);
+
+  void VisitBasicBlock(HBasicBlock* block);
+  void VisitLoadLocal(HLoadLocal* load);
+  void VisitStoreLocal(HStoreLocal* store);
+  void VisitInstruction(HInstruction* instruction);
+
+ private:
+  // Locals for the current block being visited.
+  GrowableArray<HInstruction*>* current_locals_;
+
+  // Keep track of loop headers found. The last phase of the analysis iterates
+  // over these blocks to set the inputs of their phis.
+  GrowableArray<HBasicBlock*> loop_headers_;
+
+  // HEnvironment for each block.
+  GrowableArray<HEnvironment*> locals_for_;
+
+  DISALLOW_COPY_AND_ASSIGN(SsaBuilder);
+};
+
+}  // namespace art
+
+#endif  // ART_COMPILER_OPTIMIZING_SSA_BUILDER_H_