upload android base code part3

android/art/compiler/optimizing/x86_memory_gen.cc

@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#include "x86_memory_gen.h"
+#include "code_generator.h"
+#include "driver/compiler_options.h"
+
+namespace art {
+namespace x86 {
+
+/**
+ * Replace instructions with memory operand forms.
+ */
+class MemoryOperandVisitor : public HGraphVisitor {
+ public:
+  MemoryOperandVisitor(HGraph* graph, bool do_implicit_null_checks)
+      : HGraphVisitor(graph),
+        do_implicit_null_checks_(do_implicit_null_checks) {}
+
+ private:
+  void VisitBoundsCheck(HBoundsCheck* check) OVERRIDE {
+    // Replace the length by the array itself, so that we can do compares to memory.
+    HArrayLength* array_len = check->InputAt(1)->AsArrayLength();
+
+    // We only want to replace an ArrayLength.
+    if (array_len == nullptr) {
+      return;
+    }
+
+    HInstruction* array = array_len->InputAt(0);
+    DCHECK_EQ(array->GetType(), Primitive::kPrimNot);
+
+    // Don't apply this optimization when the array is nullptr.
+    if (array->IsConstant() || (array->IsNullCheck() && array->InputAt(0)->IsConstant())) {
+      return;
+    }
+
+    // Is there a null check that could be an implicit check?
+    if (array->IsNullCheck() && do_implicit_null_checks_) {
+      // The ArrayLen may generate the implicit null check.  Can the
+      // bounds check do so as well?
+      if (array_len->GetNextDisregardingMoves() != check) {
+        // No, it won't.  Leave as is.
+        return;
+      }
+    }
+
+    // Can we suppress the ArrayLength and generate at BoundCheck?
+    if (array_len->HasOnlyOneNonEnvironmentUse()) {
+      array_len->MarkEmittedAtUseSite();
+      // We need the ArrayLength just before the BoundsCheck.
+      array_len->MoveBefore(check);
+    }
+  }
+
+  bool do_implicit_null_checks_;
+};
+
+X86MemoryOperandGeneration::X86MemoryOperandGeneration(HGraph* graph,
+                                                       CodeGenerator* codegen,
+                                                       OptimizingCompilerStats* stats)
+    : HOptimization(graph, kX86MemoryOperandGenerationPassName, stats),
+      do_implicit_null_checks_(codegen->GetCompilerOptions().GetImplicitNullChecks()) {
+}
+
+void X86MemoryOperandGeneration::Run() {
+  MemoryOperandVisitor visitor(graph_, do_implicit_null_checks_);
+  visitor.VisitInsertionOrder();
+}
+
+}  // namespace x86
+}  // namespace art