Start incorporating the ARM integrated assembler.

src/IceAssemblerARM32.cpp

+//===- subzero/src/IceAssemblerARM32.cpp - Assembler for ARM32 --*- C++ -*-===//
+//
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+//
+// Modified by the Subzero authors.
+//
+//===----------------------------------------------------------------------===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file implements the Assembler class for ARM32.
+///
+//===----------------------------------------------------------------------===//
+
+#include "IceAssemblerARM32.h"
+
+namespace Ice {
+
+Label *ARM32::AssemblerARM32::getOrCreateLabel(SizeT Number,
+                                               LabelVector &Labels) {
+  Label *L = nullptr;
+  if (Number == Labels.size()) {
+    L = new (this->allocate<Label>()) Label();
+    Labels.push_back(L);
+    return L;
+  }
+  if (Number > Labels.size()) {
+    Labels.resize(Number + 1);
+  }
+  L = Labels[Number];
+  if (!L) {
+    L = new (this->allocate<Label>()) Label();
+    Labels[Number] = L;
+  }
+  return L;
+}
+
+void ARM32::AssemblerARM32::bind(Label *label) {
+  intptr_t bound = Buffer.size();
+  assert(!label->isBound()); // Labels can only be bound once.
+  while (label->isLinked()) {
+    intptr_t position = label->getLinkPosition();
+    intptr_t next = Buffer.load<int32_t>(position);
+    Buffer.store<int32_t>(position, bound - (position + 4));
+    label->setPosition(next);
+  }
+  // TODO(kschimpf) Decide if we have near jumps.
+  label->bindTo(bound);
+}
+
+void ARM32::AssemblerARM32::bkpt(uint16_t imm16) {
+  AssemblerBuffer::EnsureCapacity ensured(&Buffer);
+  emitInt32(BkptEncoding(imm16));
+}
+
+void ARM32::AssemblerARM32::bx(RegARM32::GPRRegister rm, CondARM32::Cond cond) {
+  // cccc000100101111111111110001mmmm where mmmm=rm and cccc=Cond.
+  assert(rm != RegARM32::Encoded_Not_GPR);
+  assert(cond != CondARM32::kNone);
+  AssemblerBuffer::EnsureCapacity ensured(&Buffer);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) | B24 |
+                     B21 | (0xfff << 8) | B4 |
+                     (static_cast<int32_t>(rm) << kRmShift);
+  emitInt32(encoding);
+}
+
+} // end of namespace Ice