Emit bit manipulation instructions for x86 and x86_64

This patch performs instruction simplification to
generate instructions andn, blsmsk and blsr on
cpus that have avx2.

Test: test.py --host --64, test-art-host-gtest
Change-Id: Ie41a1b99ac2980f1e9f6a831a7d639bc3e248f0f
Signed-off-by: Shalini Salomi Bodapati <shalini.salomi.bodapati@intel.com>
diff --git a/compiler/optimizing/instruction_simplifier_x86.cc b/compiler/optimizing/instruction_simplifier_x86.cc
new file mode 100644
index 0000000..2d8f94a
--- /dev/null
+++ b/compiler/optimizing/instruction_simplifier_x86.cc
@@ -0,0 +1,88 @@
+/* Copyright (C) 2018 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 "instruction_simplifier_x86.h"
+#include "instruction_simplifier_x86_shared.h"
+#include "code_generator_x86.h"
+
+namespace art {
+
+namespace x86 {
+
+class InstructionSimplifierX86Visitor : public HGraphVisitor {
+ public:
+  InstructionSimplifierX86Visitor(HGraph* graph,
+                                  CodeGenerator* codegen,
+                                  OptimizingCompilerStats* stats)
+      : HGraphVisitor(graph),
+        codegen_(down_cast<CodeGeneratorX86*>(codegen)),
+        stats_(stats) {}
+
+  void RecordSimplification() {
+    MaybeRecordStat(stats_, MethodCompilationStat::kInstructionSimplificationsArch);
+  }
+
+  bool HasAVX2() {
+    return (codegen_->GetInstructionSetFeatures().HasAVX2());
+  }
+
+  void VisitBasicBlock(HBasicBlock* block) override {
+    for (HInstructionIterator it(block->GetInstructions()); !it.Done(); it.Advance()) {
+      HInstruction* instruction = it.Current();
+      if (instruction->IsInBlock()) {
+        instruction->Accept(this);
+      }
+    }
+  }
+
+  void VisitAnd(HAnd * instruction) override;
+  void VisitXor(HXor* instruction) override;
+
+ private:
+  CodeGeneratorX86* codegen_;
+  OptimizingCompilerStats* stats_;
+};
+
+
+void InstructionSimplifierX86Visitor::VisitAnd(HAnd* instruction) {
+  if (TryCombineAndNot(instruction)) {
+    RecordSimplification();
+  } else if (instruction->GetResultType() == DataType::Type::kInt32) {
+    if (TryGenerateResetLeastSetBit(instruction)) {
+      RecordSimplification();
+    }
+  }
+}
+
+void InstructionSimplifierX86Visitor::VisitXor(HXor* instruction) {
+  if (instruction->GetResultType() == DataType::Type::kInt32) {
+    if (TryGenerateMaskUptoLeastSetBit(instruction)) {
+      RecordSimplification();
+    }
+  }
+}
+
+bool InstructionSimplifierX86::Run() {
+  InstructionSimplifierX86Visitor visitor(graph_, codegen_, stats_);
+  if (visitor.HasAVX2()) {
+    visitor.VisitReversePostOrder();
+    return true;
+  }
+  return false;
+}
+
+}  // namespace x86
+}  // namespace art
+