Add a Transform to SSA phase to the optimizing compiler.
Change-Id: Ia9700756a0396d797a00b529896487d52c989329
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_