Fix emission of move immediate for 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 {
 
+// The following define individual bits.
+static constexpr uint32_t B0 = 1;
+static constexpr uint32_t B2 = 1 << 2;
+static constexpr uint32_t B3 = 1 << 3;
+static constexpr uint32_t B4 = 1 << 4;
+static constexpr uint32_t B5 = 1 << 5;
+static constexpr uint32_t B6 = 1 << 6;
+static constexpr uint32_t B21 = 1 << 21;
+static constexpr uint32_t B24 = 1 << 24;
+
+// Constants used for the decoding or encoding of the individual fields of
+// instructions. Based on ARM section A5.1.
+static constexpr uint32_t kConditionShift = 28;
+static constexpr uint32_t kOpcodeShift = 21;
+static constexpr uint32_t kRdShift = 12;
+static constexpr uint32_t kRmShift = 0;
+static constexpr uint32_t kRnShift = 16;
+static constexpr uint32_t kSShift = 20;
+static constexpr uint32_t kTypeShift = 25;
+
+// Immediate instruction fields encoding.
+static constexpr uint32_t kImmed8Bits = 8;
+static constexpr uint32_t kImmed8Shift = 0;
+static constexpr uint32_t kRotateBits = 4;
+static constexpr uint32_t kRotateShift = 8;
+
+// Types of instructions.
+static constexpr uint32_t kInstTypeImmediate = 1;
+
+inline uint32_t encodeBool(bool b) { return b ? 1 : 0; }
+
+inline uint32_t encodeGPRRegister(RegARM32::GPRRegister Rn) {
+  return static_cast<uint32_t>(Rn);
+}
+
+inline bool isGPRRegisterDefined(RegARM32::GPRRegister R) {
+  return R != RegARM32::Encoded_Not_GPR;
+}
+
+inline bool isGPRRegisterDefined(uint32_t R) {
+  return R != encodeGPRRegister(RegARM32::Encoded_Not_GPR);
+}
+
+inline bool isConditionDefined(CondARM32::Cond Cond) {
+  return Cond != CondARM32::kNone;
+}
+
+inline uint32_t encodeCondition(CondARM32::Cond Cond) {
+  return static_cast<uint32_t>(Cond);
+}
+
+// Converts rotated immediate into imm12.
+inline uint32_t encodeImm12FromFlexImm(const OperandARM32FlexImm &FlexImm) {
+  uint32_t Immed8 = FlexImm.getImm();
+  uint32_t Rotate = FlexImm.getRotateAmt();
+  assert((Rotate < (1 << kRotateBits)) && (Immed8 < (1 << kImmed8Bits)));
+  return (Rotate << kRotateShift) | (Immed8 << kImmed8Shift);
+}
+
 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);
@@ skipping 12 matching lines @@
   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::emitType01(CondARM32::Cond Cond, uint32_t Type,
+                                       uint32_t Opcode, bool SetCc, uint32_t Rn,
+                                       uint32_t Rd, uint32_t Imm12) {
+  assert(isGPRRegisterDefined(Rd));
+  assert(Cond != CondARM32::kNone);
+  uint32_t Encoding = encodeCondition(Cond) << kConditionShift |
+                      (Type << kTypeShift) | (Opcode << kOpcodeShift) |
+                      (encodeBool(SetCc) << kSShift) | (Rn << kRnShift) |
+                      (Rd << kRdShift) | Imm12;
+  emitInst(Encoding);
+}
+
 void ARM32::AssemblerARM32::bkpt(uint16_t imm16) {
   AssemblerBuffer::EnsureCapacity ensured(&Buffer);
-  emitInt32(BkptEncoding(imm16));
+  uint32_t Encoding = (CondARM32::AL << kConditionShift) | B24 | B21 |
+                      ((imm16 >> 4) << 8) | B6 | B5 | B4 | (imm16 & 0xf);
+  emitInst(Encoding);
 }
 
-void ARM32::AssemblerARM32::bx(RegARM32::GPRRegister rm, CondARM32::Cond cond) {
+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);
+  // (ARM section A8.8.27, encoding A1).
+  assert(isGPRRegisterDefined(Rm));
+  assert(isConditionDefined(Cond));
   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);
+  uint32_t Encoding = (encodeCondition(Cond) << kConditionShift) | B24 | B21 |
+                      (0xfff << 8) | B4 | (encodeGPRRegister(Rm) << kRmShift);
+  emitInst(Encoding);
+}
+
+void ARM32::AssemblerARM32::mov(RegARM32::GPRRegister Rd,
+                                const OperandARM32FlexImm &FlexImm,
+                                CondARM32::Cond Cond) {
+  // cccc0011101s0000ddddiiiiiiiiiiii (ARM section A8.8.102, encoding A1)
+  assert(isConditionDefined(Cond));
+  AssemblerBuffer::EnsureCapacity ensured(&Buffer);
+  bool SetCc = false; // Note: We don't use movs in this assembler.
+  uint32_t Rn = 0;
+  uint32_t Mov = B3 | B2 | B0; // 1101.
+  emitType01(Cond, kInstTypeImmediate, Mov, SetCc, Rn, encodeGPRRegister(Rd),
+             encodeImm12FromFlexImm(FlexImm));
 }
 
 } // end of namespace Ice