disas: Add subset of libvixl sources for A64 disassembler

Add the subset of the libvixl sources that are needed for the
A64 disassembler support. These sources come from
https://github.com/armvixl/vixl commit 578645f14e122d2b
which is VIXL release 1.1.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

disas/libvixl/LICENCE

+LICENCE
+=======
+
+The software in this repository is covered by the following licence.
+
+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

disas/libvixl/README

+
+The code in this directory is a subset of libvixl:
+ https://github.com/armvixl/vixl
+(specifically, it is the set of files needed for disassembly only,
+taken from libvixl 1.1).
+Bugfixes should preferably be sent upstream initially.
+
+The disassembler does not currently support the entire A64 instruction
+set. Notably:
+ * No Advanced SIMD support.
+ * Limited support for system instructions.
+ * A few miscellaneous integer and floating point instructions are missing.

disas/libvixl/a64/cpu-a64.h

+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef VIXL_CPU_A64_H
+#define VIXL_CPU_A64_H
+
+#include "globals.h"
+
+namespace vixl {
+
+class CPU {
+ public:
+  // Initialise CPU support.
+  static void SetUp();
+
+  // Ensures the data at a given address and with a given size is the same for
+  // the I and D caches. I and D caches are not automatically coherent on ARM
+  // so this operation is required before any dynamically generated code can
+  // safely run.
+  static void EnsureIAndDCacheCoherency(void *address, size_t length);
+
+ private:
+  // Return the content of the cache type register.
+  static uint32_t GetCacheType();
+
+  // I and D cache line size in bytes.
+  static unsigned icache_line_size_;
+  static unsigned dcache_line_size_;
+};
+
+}  // namespace vixl
+
+#endif  // VIXL_CPU_A64_H

disas/libvixl/a64/decoder-a64.h

+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef VIXL_A64_DECODER_A64_H_
+#define VIXL_A64_DECODER_A64_H_
+
+#include <list>
+
+#include "globals.h"
+#include "a64/instructions-a64.h"
+
+
+// List macro containing all visitors needed by the decoder class.
+
+#define VISITOR_LIST(V)             \
+  V(PCRelAddressing)                \
+  V(AddSubImmediate)                \
+  V(LogicalImmediate)               \
+  V(MoveWideImmediate)              \
+  V(Bitfield)                       \
+  V(Extract)                        \
+  V(UnconditionalBranch)            \
+  V(UnconditionalBranchToRegister)  \
+  V(CompareBranch)                  \
+  V(TestBranch)                     \
+  V(ConditionalBranch)              \
+  V(System)                         \
+  V(Exception)                      \
+  V(LoadStorePairPostIndex)         \
+  V(LoadStorePairOffset)            \
+  V(LoadStorePairPreIndex)          \
+  V(LoadStorePairNonTemporal)       \
+  V(LoadLiteral)                    \
+  V(LoadStoreUnscaledOffset)        \
+  V(LoadStorePostIndex)             \
+  V(LoadStorePreIndex)              \
+  V(LoadStoreRegisterOffset)        \
+  V(LoadStoreUnsignedOffset)        \
+  V(LogicalShifted)                 \
+  V(AddSubShifted)                  \
+  V(AddSubExtended)                 \
+  V(AddSubWithCarry)                \
+  V(ConditionalCompareRegister)     \
+  V(ConditionalCompareImmediate)    \
+  V(ConditionalSelect)              \
+  V(DataProcessing1Source)          \
+  V(DataProcessing2Source)          \
+  V(DataProcessing3Source)          \
+  V(FPCompare)                      \
+  V(FPConditionalCompare)           \
+  V(FPConditionalSelect)            \
+  V(FPImmediate)                    \
+  V(FPDataProcessing1Source)        \
+  V(FPDataProcessing2Source)        \
+  V(FPDataProcessing3Source)        \
+  V(FPIntegerConvert)               \
+  V(FPFixedPointConvert)            \
+  V(Unallocated)                    \
+  V(Unimplemented)
+
+namespace vixl {
+
+// The Visitor interface. Disassembler and simulator (and other tools)
+// must provide implementations for all of these functions.
+class DecoderVisitor {
+ public:
+  #define DECLARE(A) virtual void Visit##A(Instruction* instr) = 0;
+  VISITOR_LIST(DECLARE)
+  #undef DECLARE
+
+  virtual ~DecoderVisitor() {}
+
+ private:
+  // Visitors are registered in a list.
+  std::list<DecoderVisitor*> visitors_;
+
+  friend class Decoder;
+};
+
+
+class Decoder: public DecoderVisitor {
+ public:
+  Decoder() {}
+
+  // Top-level instruction decoder function. Decodes an instruction and calls
+  // the visitor functions registered with the Decoder class.
+  void Decode(Instruction *instr);
+
+  // Register a new visitor class with the decoder.
+  // Decode() will call the corresponding visitor method from all registered
+  // visitor classes when decoding reaches the leaf node of the instruction
+  // decode tree.
+  // Visitors are called in the order.
+  // A visitor can only be registered once.
+  // Registering an already registered visitor will update its position.
+  //
+  //   d.AppendVisitor(V1);
+  //   d.AppendVisitor(V2);
+  //   d.PrependVisitor(V2);            // Move V2 at the start of the list.
+  //   d.InsertVisitorBefore(V3, V2);
+  //   d.AppendVisitor(V4);
+  //   d.AppendVisitor(V4);             // No effect.
+  //
+  //   d.Decode(i);
+  //
+  // will call in order visitor methods in V3, V2, V1, V4.
+  void AppendVisitor(DecoderVisitor* visitor);
+  void PrependVisitor(DecoderVisitor* visitor);
+  void InsertVisitorBefore(DecoderVisitor* new_visitor,
+                           DecoderVisitor* registered_visitor);
+  void InsertVisitorAfter(DecoderVisitor* new_visitor,
+                          DecoderVisitor* registered_visitor);
+
+  // Remove a previously registered visitor class from the list of visitors
+  // stored by the decoder.
+  void RemoveVisitor(DecoderVisitor* visitor);
+
+  #define DECLARE(A) void Visit##A(Instruction* instr);
+  VISITOR_LIST(DECLARE)
+  #undef DECLARE
+
+ private:
+  // Decode the PC relative addressing instruction, and call the corresponding
+  // visitors.
+  // On entry, instruction bits 27:24 = 0x0.
+  void DecodePCRelAddressing(Instruction* instr);
+
+  // Decode the add/subtract immediate instruction, and call the correspoding
+  // visitors.
+  // On entry, instruction bits 27:24 = 0x1.
+  void DecodeAddSubImmediate(Instruction* instr);
+
+  // Decode the branch, system command, and exception generation parts of
+  // the instruction tree, and call the corresponding visitors.
+  // On entry, instruction bits 27:24 = {0x4, 0x5, 0x6, 0x7}.
+  void DecodeBranchSystemException(Instruction* instr);
+
+  // Decode the load and store parts of the instruction tree, and call
+  // the corresponding visitors.
+  // On entry, instruction bits 27:24 = {0x8, 0x9, 0xC, 0xD}.
+  void DecodeLoadStore(Instruction* instr);
+
+  // Decode the logical immediate and move wide immediate parts of the
+  // instruction tree, and call the corresponding visitors.
+  // On entry, instruction bits 27:24 = 0x2.
+  void DecodeLogical(Instruction* instr);
+
+  // Decode the bitfield and extraction parts of the instruction tree,
+  // and call the corresponding visitors.
+  // On entry, instruction bits 27:24 = 0x3.
+  void DecodeBitfieldExtract(Instruction* instr);
+
+  // Decode the data processing parts of the instruction tree, and call the
+  // corresponding visitors.
+  // On entry, instruction bits 27:24 = {0x1, 0xA, 0xB}.
+  void DecodeDataProcessing(Instruction* instr);
+
+  // Decode the floating point parts of the instruction tree, and call the
+  // corresponding visitors.
+  // On entry, instruction bits 27:24 = {0xE, 0xF}.
+  void DecodeFP(Instruction* instr);
+
+  // Decode the Advanced SIMD (NEON) load/store part of the instruction tree,
+  // and call the corresponding visitors.
+  // On entry, instruction bits 29:25 = 0x6.
+  void DecodeAdvSIMDLoadStore(Instruction* instr);
+
+  // Decode the Advanced SIMD (NEON) data processing part of the instruction
+  // tree, and call the corresponding visitors.
+  // On entry, instruction bits 27:25 = 0x7.
+  void DecodeAdvSIMDDataProcessing(Instruction* instr);
+};
+}  // namespace vixl
+
+#endif  // VIXL_A64_DECODER_A64_H_

disas/libvixl/a64/disasm-a64.h

+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef VIXL_A64_DISASM_A64_H
+#define VIXL_A64_DISASM_A64_H
+
+#include "globals.h"
+#include "utils.h"
+#include "instructions-a64.h"
+#include "decoder-a64.h"
+
+namespace vixl {
+
+class Disassembler: public DecoderVisitor {
+ public:
+  Disassembler();
+  Disassembler(char* text_buffer, int buffer_size);
+  virtual ~Disassembler();
+  char* GetOutput();
+
+  // Declare all Visitor functions.
+  #define DECLARE(A)  void Visit##A(Instruction* instr);
+  VISITOR_LIST(DECLARE)
+  #undef DECLARE
+
+ protected:
+  virtual void ProcessOutput(Instruction* instr);
+
+ private:
+  void Format(Instruction* instr, const char* mnemonic, const char* format);
+  void Substitute(Instruction* instr, const char* string);
+  int SubstituteField(Instruction* instr, const char* format);
+  int SubstituteRegisterField(Instruction* instr, const char* format);
+  int SubstituteImmediateField(Instruction* instr, const char* format);
+  int SubstituteLiteralField(Instruction* instr, const char* format);
+  int SubstituteBitfieldImmediateField(Instruction* instr, const char* format);
+  int SubstituteShiftField(Instruction* instr, const char* format);
+  int SubstituteExtendField(Instruction* instr, const char* format);
+  int SubstituteConditionField(Instruction* instr, const char* format);
+  int SubstitutePCRelAddressField(Instruction* instr, const char* format);
+  int SubstituteBranchTargetField(Instruction* instr, const char* format);
+  int SubstituteLSRegOffsetField(Instruction* instr, const char* format);
+  int SubstitutePrefetchField(Instruction* instr, const char* format);
+
+  inline bool RdIsZROrSP(Instruction* instr) const {
+    return (instr->Rd() == kZeroRegCode);
+  }
+
+  inline bool RnIsZROrSP(Instruction* instr) const {
+    return (instr->Rn() == kZeroRegCode);
+  }
+
+  inline bool RmIsZROrSP(Instruction* instr) const {
+    return (instr->Rm() == kZeroRegCode);
+  }
+
+  inline bool RaIsZROrSP(Instruction* instr) const {
+    return (instr->Ra() == kZeroRegCode);
+  }
+
+  bool IsMovzMovnImm(unsigned reg_size, uint64_t value);
+
+  void ResetOutput();
+  void AppendToOutput(const char* string, ...);
+
+  char* buffer_;
+  uint32_t buffer_pos_;
+  uint32_t buffer_size_;
+  bool own_buffer_;
+};
+
+
+class PrintDisassembler: public Disassembler {
+ public:
+  explicit PrintDisassembler(FILE* stream) : stream_(stream) { }
+  ~PrintDisassembler() { }
+
+ protected:
+  virtual void ProcessOutput(Instruction* instr);
+
+ private:
+  FILE *stream_;
+};
+}  // namespace vixl
+
+#endif  // VIXL_A64_DISASM_A64_H

disas/libvixl/a64/instructions-a64.cc

+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "a64/instructions-a64.h"
+#include "a64/assembler-a64.h"
+
+namespace vixl {
+
+
+static uint64_t RotateRight(uint64_t value,
+                            unsigned int rotate,
+                            unsigned int width) {
+  ASSERT(width <= 64);
+  rotate &= 63;
+  return ((value & ((1UL << rotate) - 1UL)) << (width - rotate)) |
+         (value >> rotate);
+}
+
+
+static uint64_t RepeatBitsAcrossReg(unsigned reg_size,
+                                    uint64_t value,
+                                    unsigned width) {
+  ASSERT((width == 2) || (width == 4) || (width == 8) || (width == 16) ||
+         (width == 32));
+  ASSERT((reg_size == kWRegSize) || (reg_size == kXRegSize));
+  uint64_t result = value & ((1UL << width) - 1UL);
+  for (unsigned i = width; i < reg_size; i *= 2) {
+    result |= (result << i);
+  }
+  return result;
+}
+
+
+// Logical immediates can't encode zero, so a return value of zero is used to
+// indicate a failure case. Specifically, where the constraints on imm_s are
+// not met.
+uint64_t Instruction::ImmLogical() {
+  unsigned reg_size = SixtyFourBits() ? kXRegSize : kWRegSize;
+  int64_t n = BitN();
+  int64_t imm_s = ImmSetBits();
+  int64_t imm_r = ImmRotate();
+
+  // An integer is constructed from the n, imm_s and imm_r bits according to
+  // the following table:
+  //
+  //  N   imms    immr    size        S             R
+  //  1  ssssss  rrrrrr    64    UInt(ssssss)  UInt(rrrrrr)
+  //  0  0sssss  xrrrrr    32    UInt(sssss)   UInt(rrrrr)
+  //  0  10ssss  xxrrrr    16    UInt(ssss)    UInt(rrrr)
+  //  0  110sss  xxxrrr     8    UInt(sss)     UInt(rrr)
+  //  0  1110ss  xxxxrr     4    UInt(ss)      UInt(rr)
+  //  0  11110s  xxxxxr     2    UInt(s)       UInt(r)
+  // (s bits must not be all set)
+  //
+  // A pattern is constructed of size bits, where the least significant S+1
+  // bits are set. The pattern is rotated right by R, and repeated across a
+  // 32 or 64-bit value, depending on destination register width.
+  //
+
+  if (n == 1) {
+    if (imm_s == 0x3F) {
+      return 0;
+    }
+    uint64_t bits = (1UL << (imm_s + 1)) - 1;
+    return RotateRight(bits, imm_r, 64);
+  } else {
+    if ((imm_s >> 1) == 0x1F) {
+      return 0;
+    }
+    for (int width = 0x20; width >= 0x2; width >>= 1) {
+      if ((imm_s & width) == 0) {
+        int mask = width - 1;
+        if ((imm_s & mask) == mask) {
+          return 0;
+        }
+        uint64_t bits = (1UL << ((imm_s & mask) + 1)) - 1;
+        return RepeatBitsAcrossReg(reg_size,
+                                   RotateRight(bits, imm_r & mask, width),
+                                   width);
+      }
+    }
+  }
+  UNREACHABLE();
+  return 0;
+}
+
+
+float Instruction::ImmFP32() {
+  //  ImmFP: abcdefgh (8 bits)
+  // Single: aBbb.bbbc.defg.h000.0000.0000.0000.0000 (32 bits)
+  // where B is b ^ 1
+  uint32_t bits = ImmFP();
+  uint32_t bit7 = (bits >> 7) & 0x1;
+  uint32_t bit6 = (bits >> 6) & 0x1;
+  uint32_t bit5_to_0 = bits & 0x3f;
+  uint32_t result = (bit7 << 31) | ((32 - bit6) << 25) | (bit5_to_0 << 19);
+
+  return rawbits_to_float(result);
+}
+
+
+double Instruction::ImmFP64() {
+  //  ImmFP: abcdefgh (8 bits)
+  // Double: aBbb.bbbb.bbcd.efgh.0000.0000.0000.0000
+  //         0000.0000.0000.0000.0000.0000.0000.0000 (64 bits)
+  // where B is b ^ 1
+  uint32_t bits = ImmFP();
+  uint64_t bit7 = (bits >> 7) & 0x1;
+  uint64_t bit6 = (bits >> 6) & 0x1;
+  uint64_t bit5_to_0 = bits & 0x3f;
+  uint64_t result = (bit7 << 63) | ((256 - bit6) << 54) | (bit5_to_0 << 48);
+
+  return rawbits_to_double(result);
+}
+
+
+LSDataSize CalcLSPairDataSize(LoadStorePairOp op) {
+  switch (op) {
+    case STP_x:
+    case LDP_x:
+    case STP_d:
+    case LDP_d: return LSDoubleWord;
+    default: return LSWord;
+  }
+}
+
+
+Instruction* Instruction::ImmPCOffsetTarget() {
+  ptrdiff_t offset;
+  if (IsPCRelAddressing()) {
+    // PC-relative addressing. Only ADR is supported.
+    offset = ImmPCRel();
+  } else {
+    // All PC-relative branches.
+    ASSERT(BranchType() != UnknownBranchType);
+    // Relative branch offsets are instruction-size-aligned.
+    offset = ImmBranch() << kInstructionSizeLog2;
+  }
+  return this + offset;
+}
+
+
+inline int Instruction::ImmBranch() const {
+  switch (BranchType()) {
+    case CondBranchType: return ImmCondBranch();
+    case UncondBranchType: return ImmUncondBranch();
+    case CompareBranchType: return ImmCmpBranch();
+    case TestBranchType: return ImmTestBranch();
+    default: UNREACHABLE();
+  }
+  return 0;
+}
+
+
+void Instruction::SetImmPCOffsetTarget(Instruction* target) {
+  if (IsPCRelAddressing()) {
+    SetPCRelImmTarget(target);
+  } else {
+    SetBranchImmTarget(target);
+  }
+}
+
+
+void Instruction::SetPCRelImmTarget(Instruction* target) {
+  // ADRP is not supported, so 'this' must point to an ADR instruction.
+  ASSERT(Mask(PCRelAddressingMask) == ADR);
+
+  Instr imm = Assembler::ImmPCRelAddress(target - this);
+
+  SetInstructionBits(Mask(~ImmPCRel_mask) | imm);
+}
+
+
+void Instruction::SetBranchImmTarget(Instruction* target) {
+  ASSERT(((target - this) & 3) == 0);
+  Instr branch_imm = 0;
+  uint32_t imm_mask = 0;
+  int offset = (target - this) >> kInstructionSizeLog2;
+  switch (BranchType()) {
+    case CondBranchType: {
+      branch_imm = Assembler::ImmCondBranch(offset);
+      imm_mask = ImmCondBranch_mask;
+      break;
+    }
+    case UncondBranchType: {
+      branch_imm = Assembler::ImmUncondBranch(offset);
+      imm_mask = ImmUncondBranch_mask;
+      break;
+    }
+    case CompareBranchType: {
+      branch_imm = Assembler::ImmCmpBranch(offset);
+      imm_mask = ImmCmpBranch_mask;
+      break;
+    }
+    case TestBranchType: {
+      branch_imm = Assembler::ImmTestBranch(offset);
+      imm_mask = ImmTestBranch_mask;
+      break;
+    }
+    default: UNREACHABLE();
+  }
+  SetInstructionBits(Mask(~imm_mask) | branch_imm);
+}
+
+
+void Instruction::SetImmLLiteral(Instruction* source) {
+  ASSERT(((source - this) & 3) == 0);
+  int offset = (source - this) >> kLiteralEntrySizeLog2;
+  Instr imm = Assembler::ImmLLiteral(offset);
+  Instr mask = ImmLLiteral_mask;
+
+  SetInstructionBits(Mask(~mask) | imm);
+}
+}  // namespace vixl
+

disas/libvixl/a64/instructions-a64.h

+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef VIXL_A64_INSTRUCTIONS_A64_H_
+#define VIXL_A64_INSTRUCTIONS_A64_H_
+
+#include "globals.h"
+#include "utils.h"
+#include "a64/constants-a64.h"
+
+namespace vixl {
+// ISA constants. --------------------------------------------------------------
+
+typedef uint32_t Instr;
+const unsigned kInstructionSize = 4;
+const unsigned kInstructionSizeLog2 = 2;
+const unsigned kLiteralEntrySize = 4;
+const unsigned kLiteralEntrySizeLog2 = 2;
+const unsigned kMaxLoadLiteralRange = 1 * MBytes;
+
+const unsigned kWRegSize = 32;
+const unsigned kWRegSizeLog2 = 5;
+const unsigned kWRegSizeInBytes = kWRegSize / 8;
+const unsigned kXRegSize = 64;
+const unsigned kXRegSizeLog2 = 6;
+const unsigned kXRegSizeInBytes = kXRegSize / 8;
+const unsigned kSRegSize = 32;
+const unsigned kSRegSizeLog2 = 5;
+const unsigned kSRegSizeInBytes = kSRegSize / 8;
+const unsigned kDRegSize = 64;
+const unsigned kDRegSizeLog2 = 6;
+const unsigned kDRegSizeInBytes = kDRegSize / 8;
+const int64_t kWRegMask = 0x00000000ffffffffL;
+const int64_t kXRegMask = 0xffffffffffffffffL;
+const int64_t kSRegMask = 0x00000000ffffffffL;
+const int64_t kDRegMask = 0xffffffffffffffffL;
+const int64_t kXSignMask = 0x1L << 63;
+const int64_t kWSignMask = 0x1L << 31;
+const int64_t kByteMask = 0xffL;
+const int64_t kHalfWordMask = 0xffffL;
+const int64_t kWordMask = 0xffffffffL;
+const uint64_t kXMaxUInt = 0xffffffffffffffffUL;
+const uint64_t kWMaxUInt = 0xffffffffUL;
+const int64_t kXMaxInt = 0x7fffffffffffffffL;
+const int64_t kXMinInt = 0x8000000000000000L;
+const int32_t kWMaxInt = 0x7fffffff;
+const int32_t kWMinInt = 0x80000000;
+const unsigned kLinkRegCode = 30;
+const unsigned kZeroRegCode = 31;
+const unsigned kSPRegInternalCode = 63;
+const unsigned kRegCodeMask = 0x1f;
+
+// AArch64 floating-point specifics. These match IEEE-754.
+const unsigned kDoubleMantissaBits = 52;
+const unsigned kDoubleExponentBits = 11;
+const unsigned kFloatMantissaBits = 23;
+const unsigned kFloatExponentBits = 8;
+
+const float kFP32PositiveInfinity = rawbits_to_float(0x7f800000);
+const float kFP32NegativeInfinity = rawbits_to_float(0xff800000);
+const double kFP64PositiveInfinity = rawbits_to_double(0x7ff0000000000000UL);
+const double kFP64NegativeInfinity = rawbits_to_double(0xfff0000000000000UL);
+
+// This value is a signalling NaN as both a double and as a float (taking the
+// least-significant word).
+static const double kFP64SignallingNaN = rawbits_to_double(0x7ff000007f800001);
+static const float kFP32SignallingNaN = rawbits_to_float(0x7f800001);
+
+// A similar value, but as a quiet NaN.
+static const double kFP64QuietNaN = rawbits_to_double(0x7ff800007fc00001);
+static const float kFP32QuietNaN = rawbits_to_float(0x7fc00001);
+
+enum LSDataSize {
+  LSByte        = 0,
+  LSHalfword    = 1,
+  LSWord        = 2,
+  LSDoubleWord  = 3
+};
+
+LSDataSize CalcLSPairDataSize(LoadStorePairOp op);
+
+enum ImmBranchType {
+  UnknownBranchType = 0,
+  CondBranchType    = 1,
+  UncondBranchType  = 2,
+  CompareBranchType = 3,
+  TestBranchType    = 4
+};
+
+enum AddrMode {
+  Offset,
+  PreIndex,
+  PostIndex
+};
+
+enum FPRounding {
+  // The first four values are encodable directly by FPCR<RMode>.
+  FPTieEven = 0x0,
+  FPPositiveInfinity = 0x1,
+  FPNegativeInfinity = 0x2,
+  FPZero = 0x3,
+
+  // The final rounding mode is only available when explicitly specified by the
+  // instruction (such as with fcvta). It cannot be set in FPCR.
+  FPTieAway
+};
+
+enum Reg31Mode {
+  Reg31IsStackPointer,
+  Reg31IsZeroRegister
+};
+
+// Instructions. ---------------------------------------------------------------
+
+class Instruction {
+ public:
+  inline Instr InstructionBits() const {
+    return *(reinterpret_cast<const Instr*>(this));
+  }
+
+  inline void SetInstructionBits(Instr new_instr) {
+    *(reinterpret_cast<Instr*>(this)) = new_instr;
+  }
+
+  inline int Bit(int pos) const {
+    return (InstructionBits() >> pos) & 1;
+  }
+
+  inline uint32_t Bits(int msb, int lsb) const {
+    return unsigned_bitextract_32(msb, lsb, InstructionBits());
+  }
+
+  inline int32_t SignedBits(int msb, int lsb) const {
+    int32_t bits = *(reinterpret_cast<const int32_t*>(this));
+    return signed_bitextract_32(msb, lsb, bits);
+  }
+
+  inline Instr Mask(uint32_t mask) const {
+    return InstructionBits() & mask;
+  }
+
+  #define DEFINE_GETTER(Name, HighBit, LowBit, Func)             \
+  inline int64_t Name() const { return Func(HighBit, LowBit); }
+  INSTRUCTION_FIELDS_LIST(DEFINE_GETTER)
+  #undef DEFINE_GETTER
+
+  // ImmPCRel is a compound field (not present in INSTRUCTION_FIELDS_LIST),
+  // formed from ImmPCRelLo and ImmPCRelHi.
+  int ImmPCRel() const {
+    int const offset = ((ImmPCRelHi() << ImmPCRelLo_width) | ImmPCRelLo());
+    int const width = ImmPCRelLo_width + ImmPCRelHi_width;
+    return signed_bitextract_32(width-1, 0, offset);
+  }
+
+  uint64_t ImmLogical();
+  float ImmFP32();
+  double ImmFP64();
+
+  inline LSDataSize SizeLSPair() const {
+    return CalcLSPairDataSize(
+             static_cast<LoadStorePairOp>(Mask(LoadStorePairMask)));
+  }
+
+  // Helpers.
+  inline bool IsCondBranchImm() const {
+    return Mask(ConditionalBranchFMask) == ConditionalBranchFixed;
+  }
+
+  inline bool IsUncondBranchImm() const {
+    return Mask(UnconditionalBranchFMask) == UnconditionalBranchFixed;
+  }
+
+  inline bool IsCompareBranch() const {
+    return Mask(CompareBranchFMask) == CompareBranchFixed;
+  }
+
+  inline bool IsTestBranch() const {
+    return Mask(TestBranchFMask) == TestBranchFixed;
+  }
+
+  inline bool IsPCRelAddressing() const {
+    return Mask(PCRelAddressingFMask) == PCRelAddressingFixed;
+  }
+
+  inline bool IsLogicalImmediate() const {
+    return Mask(LogicalImmediateFMask) == LogicalImmediateFixed;
+  }
+
+  inline bool IsAddSubImmediate() const {
+    return Mask(AddSubImmediateFMask) == AddSubImmediateFixed;
+  }
+
+  inline bool IsAddSubExtended() const {
+    return Mask(AddSubExtendedFMask) == AddSubExtendedFixed;
+  }
+
+  inline bool IsLoadOrStore() const {
+    return Mask(LoadStoreAnyFMask) == LoadStoreAnyFixed;
+  }
+
+  inline bool IsMovn() const {
+    return (Mask(MoveWideImmediateMask) == MOVN_x) ||
+           (Mask(MoveWideImmediateMask) == MOVN_w);
+  }
+
+  // Indicate whether Rd can be the stack pointer or the zero register. This
+  // does not check that the instruction actually has an Rd field.
+  inline Reg31Mode RdMode() const {
+    // The following instructions use sp or wsp as Rd:
+    //  Add/sub (immediate) when not setting the flags.
+    //  Add/sub (extended) when not setting the flags.
+    //  Logical (immediate) when not setting the flags.
+    // Otherwise, r31 is the zero register.
+    if (IsAddSubImmediate() || IsAddSubExtended()) {
+      if (Mask(AddSubSetFlagsBit)) {
+        return Reg31IsZeroRegister;
+      } else {
+        return Reg31IsStackPointer;
+      }
+    }
+    if (IsLogicalImmediate()) {
+      // Of the logical (immediate) instructions, only ANDS (and its aliases)
+      // can set the flags. The others can all write into sp.
+      // Note that some logical operations are not available to
+      // immediate-operand instructions, so we have to combine two masks here.
+      if (Mask(LogicalImmediateMask & LogicalOpMask) == ANDS) {
+        return Reg31IsZeroRegister;
+      } else {
+        return Reg31IsStackPointer;
+      }
+    }
+    return Reg31IsZeroRegister;
+  }
+
+  // Indicate whether Rn can be the stack pointer or the zero register. This
+  // does not check that the instruction actually has an Rn field.
+  inline Reg31Mode RnMode() const {
+    // The following instructions use sp or wsp as Rn:
+    //  All loads and stores.
+    //  Add/sub (immediate).
+    //  Add/sub (extended).
+    // Otherwise, r31 is the zero register.
+    if (IsLoadOrStore() || IsAddSubImmediate() || IsAddSubExtended()) {
+      return Reg31IsStackPointer;
+    }
+    return Reg31IsZeroRegister;
+  }
+
+  inline ImmBranchType BranchType() const {
+    if (IsCondBranchImm()) {
+      return CondBranchType;
+    } else if (IsUncondBranchImm()) {
+      return UncondBranchType;
+    } else if (IsCompareBranch()) {
+      return CompareBranchType;
+    } else if (IsTestBranch()) {
+      return TestBranchType;
+    } else {
+      return UnknownBranchType;
+    }
+  }
+
+  // Find the target of this instruction. 'this' may be a branch or a
+  // PC-relative addressing instruction.
+  Instruction* ImmPCOffsetTarget();
+
+  // Patch a PC-relative offset to refer to 'target'. 'this' may be a branch or
+  // a PC-relative addressing instruction.
+  void SetImmPCOffsetTarget(Instruction* target);
+  // Patch a literal load instruction to load from 'source'.
+  void SetImmLLiteral(Instruction* source);
+
+  inline uint8_t* LiteralAddress() {
+    int offset = ImmLLiteral() << kLiteralEntrySizeLog2;
+    return reinterpret_cast<uint8_t*>(this) + offset;
+  }
+
+  inline uint32_t Literal32() {
+    uint32_t literal;
+    memcpy(&literal, LiteralAddress(), sizeof(literal));
+
+    return literal;
+  }
+
+  inline uint64_t Literal64() {
+    uint64_t literal;
+    memcpy(&literal, LiteralAddress(), sizeof(literal));
+
+    return literal;
+  }
+
+  inline float LiteralFP32() {
+    return rawbits_to_float(Literal32());
+  }
+
+  inline double LiteralFP64() {
+    return rawbits_to_double(Literal64());
+  }
+
+  inline Instruction* NextInstruction() {
+    return this + kInstructionSize;
+  }
+
+  inline Instruction* InstructionAtOffset(int64_t offset) {
+    ASSERT(IsWordAligned(this + offset));
+    return this + offset;
+  }
+
+  template<typename T> static inline Instruction* Cast(T src) {
+    return reinterpret_cast<Instruction*>(src);
+  }
+
+ private:
+  inline int ImmBranch() const;
+
+  void SetPCRelImmTarget(Instruction* target);
+  void SetBranchImmTarget(Instruction* target);
+};
+}  // namespace vixl
+
+#endif  // VIXL_A64_INSTRUCTIONS_A64_H_

disas/libvixl/globals.h

+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef VIXL_GLOBALS_H
+#define VIXL_GLOBALS_H
+
+// Get the standard printf format macros for C99 stdint types.
+#define __STDC_FORMAT_MACROS
+#include <inttypes.h>
+
+#include <assert.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include "platform.h"
+
+
+typedef uint8_t byte;
+
+const int KBytes = 1024;
+const int MBytes = 1024 * KBytes;
+const int GBytes = 1024 * MBytes;
+
+  #define ABORT() printf("in %s, line %i", __FILE__, __LINE__); abort()
+#ifdef DEBUG
+  #define ASSERT(condition) assert(condition)
+  #define CHECK(condition) ASSERT(condition)
+  #define UNIMPLEMENTED() printf("UNIMPLEMENTED\t"); ABORT()
+  #define UNREACHABLE() printf("UNREACHABLE\t"); ABORT()
+#else
+  #define ASSERT(condition) ((void) 0)
+  #define CHECK(condition) assert(condition)
+  #define UNIMPLEMENTED() ((void) 0)
+  #define UNREACHABLE() ((void) 0)
+#endif
+
+template <typename T> inline void USE(T) {}
+
+#define ALIGNMENT_EXCEPTION() printf("ALIGNMENT EXCEPTION\t"); ABORT()
+
+#endif  // VIXL_GLOBALS_H

disas/libvixl/platform.h

+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef PLATFORM_H
+#define PLATFORM_H
+
+// Define platform specific functionalities.
+
+namespace vixl {
+#ifdef USE_SIMULATOR
+// Currently we assume running the simulator implies running on x86 hardware.
+inline void HostBreakpoint() { asm("int3"); }
+#else
+inline void HostBreakpoint() {
+  // TODO: Implement HostBreakpoint on a64.
+}
+#endif
+}  // namespace vixl
+
+#endif

disas/libvixl/utils.cc

+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "utils.h"
+#include <stdio.h>
+
+namespace vixl {
+
+uint32_t float_to_rawbits(float value) {
+  uint32_t bits = 0;
+  memcpy(&bits, &value, 4);
+  return bits;
+}
+
+
+uint64_t double_to_rawbits(double value) {
+  uint64_t bits = 0;
+  memcpy(&bits, &value, 8);
+  return bits;
+}
+
+
+float rawbits_to_float(uint32_t bits) {
+  float value = 0.0;
+  memcpy(&value, &bits, 4);
+  return value;
+}
+
+
+double rawbits_to_double(uint64_t bits) {
+  double value = 0.0;
+  memcpy(&value, &bits, 8);
+  return value;
+}
+
+
+int CountLeadingZeros(uint64_t value, int width) {
+  ASSERT((width == 32) || (width == 64));
+  int count = 0;
+  uint64_t bit_test = 1UL << (width - 1);
+  while ((count < width) && ((bit_test & value) == 0)) {
+    count++;
+    bit_test >>= 1;
+  }
+  return count;
+}
+
+
+int CountLeadingSignBits(int64_t value, int width) {
+  ASSERT((width == 32) || (width == 64));
+  if (value >= 0) {
+    return CountLeadingZeros(value, width) - 1;
+  } else {
+    return CountLeadingZeros(~value, width) - 1;
+  }
+}
+
+
+int CountTrailingZeros(uint64_t value, int width) {
+  ASSERT((width == 32) || (width == 64));
+  int count = 0;
+  while ((count < width) && (((value >> count) & 1) == 0)) {
+    count++;
+  }
+  return count;
+}
+
+
+int CountSetBits(uint64_t value, int width) {
+  // TODO: Other widths could be added here, as the implementation already
+  // supports them.
+  ASSERT((width == 32) || (width == 64));
+
+  // Mask out unused bits to ensure that they are not counted.
+  value &= (0xffffffffffffffffUL >> (64-width));
+
+  // Add up the set bits.
+  // The algorithm works by adding pairs of bit fields together iteratively,
+  // where the size of each bit field doubles each time.
+  // An example for an 8-bit value:
+  // Bits:  h  g  f  e  d  c  b  a
+  //         \ |   \ |   \ |   \ |
+  // value = h+g   f+e   d+c   b+a
+  //            \    |      \    |
+  // value =   h+g+f+e     d+c+b+a
+  //                  \          |
+  // value =       h+g+f+e+d+c+b+a
+  value = ((value >> 1) & 0x5555555555555555) + (value & 0x5555555555555555);
+  value = ((value >> 2) & 0x3333333333333333) + (value & 0x3333333333333333);
+  value = ((value >> 4) & 0x0f0f0f0f0f0f0f0f) + (value & 0x0f0f0f0f0f0f0f0f);
+  value = ((value >> 8) & 0x00ff00ff00ff00ff) + (value & 0x00ff00ff00ff00ff);
+  value = ((value >> 16) & 0x0000ffff0000ffff) + (value & 0x0000ffff0000ffff);
+  value = ((value >> 32) & 0x00000000ffffffff) + (value & 0x00000000ffffffff);
+
+  return value;
+}
+}  // namespace vixl

disas/libvixl/utils.h

+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef VIXL_UTILS_H
+#define VIXL_UTILS_H
+
+
+#include <string.h>
+#include "globals.h"
+
+namespace vixl {
+
+// Check number width.
+inline bool is_intn(unsigned n, int64_t x) {
+  ASSERT((0 < n) && (n < 64));
+  int64_t limit = 1L << (n - 1);
+  return (-limit <= x) && (x < limit);
+}
+
+inline bool is_uintn(unsigned n, int64_t x) {
+  ASSERT((0 < n) && (n < 64));
+  return !(x >> n);
+}
+
+inline unsigned truncate_to_intn(unsigned n, int64_t x) {
+  ASSERT((0 < n) && (n < 64));
+  return (x & ((1L << n) - 1));
+}
+
+#define INT_1_TO_63_LIST(V)                                                    \
+V(1)  V(2)  V(3)  V(4)  V(5)  V(6)  V(7)  V(8)                                 \
+V(9)  V(10) V(11) V(12) V(13) V(14) V(15) V(16)                                \
+V(17) V(18) V(19) V(20) V(21) V(22) V(23) V(24)                                \
+V(25) V(26) V(27) V(28) V(29) V(30) V(31) V(32)                                \
+V(33) V(34) V(35) V(36) V(37) V(38) V(39) V(40)                                \
+V(41) V(42) V(43) V(44) V(45) V(46) V(47) V(48)                                \
+V(49) V(50) V(51) V(52) V(53) V(54) V(55) V(56)                                \
+V(57) V(58) V(59) V(60) V(61) V(62) V(63)
+
+#define DECLARE_IS_INT_N(N)                                                    \
+inline bool is_int##N(int64_t x) { return is_intn(N, x); }
+#define DECLARE_IS_UINT_N(N)                                                   \
+inline bool is_uint##N(int64_t x) { return is_uintn(N, x); }
+#define DECLARE_TRUNCATE_TO_INT_N(N)                                           \
+inline int truncate_to_int##N(int x) { return truncate_to_intn(N, x); }
+INT_1_TO_63_LIST(DECLARE_IS_INT_N)
+INT_1_TO_63_LIST(DECLARE_IS_UINT_N)
+INT_1_TO_63_LIST(DECLARE_TRUNCATE_TO_INT_N)
+#undef DECLARE_IS_INT_N
+#undef DECLARE_IS_UINT_N
+#undef DECLARE_TRUNCATE_TO_INT_N
+
+// Bit field extraction.
+inline uint32_t unsigned_bitextract_32(int msb, int lsb, uint32_t x) {
+  return (x >> lsb) & ((1 << (1 + msb - lsb)) - 1);
+}
+
+inline uint64_t unsigned_bitextract_64(int msb, int lsb, uint64_t x) {
+  return (x >> lsb) & ((static_cast<uint64_t>(1) << (1 + msb - lsb)) - 1);
+}
+
+inline int32_t signed_bitextract_32(int msb, int lsb, int32_t x) {
+  return (x << (31 - msb)) >> (lsb + 31 - msb);
+}
+
+inline int64_t signed_bitextract_64(int msb, int lsb, int64_t x) {
+  return (x << (63 - msb)) >> (lsb + 63 - msb);
+}
+
+// floating point representation
+uint32_t float_to_rawbits(float value);
+uint64_t double_to_rawbits(double value);
+float rawbits_to_float(uint32_t bits);
+double rawbits_to_double(uint64_t bits);
+
+// Bits counting.
+int CountLeadingZeros(uint64_t value, int width);
+int CountLeadingSignBits(int64_t value, int width);
+int CountTrailingZeros(uint64_t value, int width);
+int CountSetBits(uint64_t value, int width);
+
+// Pointer alignment
+// TODO: rename/refactor to make it specific to instructions.
+template<typename T>
+bool IsWordAligned(T pointer) {
+  ASSERT(sizeof(pointer) == sizeof(intptr_t));   // NOLINT(runtime/sizeof)
+  return (reinterpret_cast<intptr_t>(pointer) & 3) == 0;
+}
+
+// Increment a pointer until it has the specified alignment.
+template<class T>
+T AlignUp(T pointer, size_t alignment) {
+  ASSERT(sizeof(pointer) == sizeof(uintptr_t));
+  uintptr_t pointer_raw = reinterpret_cast<uintptr_t>(pointer);
+  size_t align_step = (alignment - pointer_raw) % alignment;
+  ASSERT((pointer_raw + align_step) % alignment == 0);
+  return reinterpret_cast<T>(pointer_raw + align_step);
+}
+
+
+}  // namespace vixl
+
+#endif  // VIXL_UTILS_H