Revert "Revert "ARM: VIXL32: Add an initial code generator that passes codegen_tests.""

This VIXL32-based code generator is not enabled in the optimizing
compiler by default. Changes in codegen_test.cc test it in parallel with
the existing ARM backend.

This patch provides a base for further work, the new backend will not
be enabled in the optimizing compiler until parity is proven with the
current ARM backend and assembler.

Test: gtest-codegen_test on host and target

This reverts commit 7863a2152865a12ad9593d8caad32698264153c1.

Change-Id: Ia09627bac22e78732ca982d207dc0b00bda435bb
diff --git a/compiler/optimizing/common_arm.h b/compiler/optimizing/common_arm.h
new file mode 100644
index 0000000..8535417
--- /dev/null
+++ b/compiler/optimizing/common_arm.h
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 2016 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_COMMON_ARM_H_
+#define ART_COMPILER_OPTIMIZING_COMMON_ARM_H_
+
+// TODO(VIXL): Make VIXL compile with -Wshadow.
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wshadow"
+#include "aarch32/macro-assembler-aarch32.h"
+#pragma GCC diagnostic pop
+
+namespace art {
+namespace arm {
+namespace helpers {
+
+static_assert(vixl::aarch32::kSpCode == SP, "vixl::aarch32::kSpCode must equal ART's SP");
+
+inline dwarf::Reg DWARFReg(vixl::aarch32::Register reg) {
+  return dwarf::Reg::ArmCore(static_cast<int>(reg.GetCode()));
+}
+
+inline dwarf::Reg DWARFReg(vixl::aarch32::SRegister reg) {
+  return dwarf::Reg::ArmFp(static_cast<int>(reg.GetCode()));
+}
+
+inline vixl::aarch32::DRegister FromLowSToD(vixl::aarch32::SRegister reg) {
+  DCHECK_EQ(reg.GetCode() % 2, 0u) << reg;
+  return vixl::aarch32::DRegister(reg.GetCode() / 2);
+}
+
+inline vixl::aarch32::Register RegisterFrom(Location location) {
+  DCHECK(location.IsRegister()) << location;
+  return vixl::aarch32::Register(location.reg());
+}
+
+inline vixl::aarch32::Register RegisterFrom(Location location, Primitive::Type type) {
+  DCHECK(type != Primitive::kPrimVoid && !Primitive::IsFloatingPointType(type)) << type;
+  return RegisterFrom(location);
+}
+
+inline vixl::aarch32::DRegister DRegisterFrom(Location location) {
+  DCHECK(location.IsFpuRegister()) << location;
+  return vixl::aarch32::DRegister(location.reg());
+}
+
+inline vixl::aarch32::SRegister SRegisterFrom(Location location) {
+  DCHECK(location.IsFpuRegister()) << location;
+  return vixl::aarch32::SRegister(location.reg());
+}
+
+inline vixl::aarch32::SRegister OutputSRegister(HInstruction* instr) {
+  Primitive::Type type = instr->GetType();
+  DCHECK_EQ(type, Primitive::kPrimFloat) << type;
+  return SRegisterFrom(instr->GetLocations()->Out());
+}
+
+inline vixl::aarch32::DRegister OutputDRegister(HInstruction* instr) {
+  Primitive::Type type = instr->GetType();
+  DCHECK_EQ(type, Primitive::kPrimDouble) << type;
+  return DRegisterFrom(instr->GetLocations()->Out());
+}
+
+inline vixl::aarch32::SRegister InputSRegisterAt(HInstruction* instr, int input_index) {
+  Primitive::Type type = instr->InputAt(input_index)->GetType();
+  DCHECK_EQ(type, Primitive::kPrimFloat) << type;
+  return SRegisterFrom(instr->GetLocations()->InAt(input_index));
+}
+
+inline vixl::aarch32::DRegister InputDRegisterAt(HInstruction* instr, int input_index) {
+  Primitive::Type type = instr->InputAt(input_index)->GetType();
+  DCHECK_EQ(type, Primitive::kPrimDouble) << type;
+  return DRegisterFrom(instr->GetLocations()->InAt(input_index));
+}
+
+inline vixl::aarch32::Register OutputRegister(HInstruction* instr) {
+  return RegisterFrom(instr->GetLocations()->Out(), instr->GetType());
+}
+
+inline vixl::aarch32::Register InputRegisterAt(HInstruction* instr, int input_index) {
+  return RegisterFrom(instr->GetLocations()->InAt(input_index),
+                      instr->InputAt(input_index)->GetType());
+}
+
+inline int64_t Int64ConstantFrom(Location location) {
+  HConstant* instr = location.GetConstant();
+  if (instr->IsIntConstant()) {
+    return instr->AsIntConstant()->GetValue();
+  } else if (instr->IsNullConstant()) {
+    return 0;
+  } else {
+    DCHECK(instr->IsLongConstant()) << instr->DebugName();
+    return instr->AsLongConstant()->GetValue();
+  }
+}
+
+inline vixl::aarch32::Operand OperandFrom(Location location, Primitive::Type type) {
+  if (location.IsRegister()) {
+    return vixl::aarch32::Operand(RegisterFrom(location, type));
+  } else {
+    return vixl::aarch32::Operand(Int64ConstantFrom(location));
+  }
+}
+
+inline vixl::aarch32::Operand InputOperandAt(HInstruction* instr, int input_index) {
+  return OperandFrom(instr->GetLocations()->InAt(input_index),
+                     instr->InputAt(input_index)->GetType());
+}
+
+}  // namespace helpers
+}  // namespace arm
+}  // namespace art
+
+#endif  // ART_COMPILER_OPTIMIZING_COMMON_ARM_H_