/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* compile-time and runtime tests for whether to use SSE instructions */

#ifndef mozilla_arm_h_
#define mozilla_arm_h_

// for definition of NS_COM_GLUE
#include "nscore.h"

/* This is patterned after SSE.h, but provides ARMv5E, ARMv6, and NEON
   detection. For reasons similar to the SSE code, code using NEON (even just
   in inline asm) needs to be in a separate compilation unit from the regular
   code, because it requires an ".fpu neon" directive which can't be undone.
   ARMv5E and ARMv6 code may also require an .arch directive, since by default
   the assembler refuses to generate code for opcodes outside of its current
   .arch setting.

   TODO: Add Thumb, Thumb2, VFP, iwMMX, etc. detection, if we need it. */

#if defined(__GNUC__) && defined(__arm__)

#  define MOZILLA_ARM_ARCH 3

#  if defined(__ARM_ARCH_4__) || defined(__ARM_ARCH_4T__) \
   || defined(_ARM_ARCH_4)
#    undef MOZILLA_ARM_ARCH
#    define MOZILLA_ARM_ARCH 4
#  endif

#  if defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5T__) \
   || defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__) \
   || defined(__ARM_ARCH_5TEJ__) || defined(_ARM_ARCH_5)
#    undef MOZILLA_ARM_ARCH
#    define MOZILLA_ARM_ARCH 5
#  endif

#  if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \
   || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \
   || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) \
   || defined(__ARM_ARCH_6M__) || defined(_ARM_ARCH_6)
#    undef MOZILLA_ARM_ARCH
#    define MOZILLA_ARM_ARCH 6
#  endif

#  if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \
   || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \
   || defined(__ARM_ARCH_7EM__) || defined(_ARM_ARCH_7)
#    undef MOZILLA_ARM_ARCH
#    define MOZILLA_ARM_ARCH 7
#  endif


#  if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
#    define MOZILLA_MAY_SUPPORT_EDSP 1
#  endif

#  if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
#    if defined(HAVE_ARM_SIMD)
#      define MOZILLA_MAY_SUPPORT_ARMV6 1
#    endif
#  endif

  // Technically 4.2.x only works in the CodeSourcery releases, but I don't
  // know how to detect those separately from mainline gcc (which got support
  // in 4.3). The Maemo version 5 SDK shipped with the CodeSourcery 4.2.1
  // release, which we need to work.
#  if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 2)
#    if defined(HAVE_ARM_NEON)
#      define MOZILLA_MAY_SUPPORT_NEON 1
#    endif
#  endif

  // When using -mfpu=neon, gcc generates neon instructions.

#  if defined(__ARM_NEON__)
#    define MOZILLA_PRESUME_NEON 1
#  endif

  // Currently we only have CPU detection for Linux via /proc/cpuinfo
#  if defined(__linux__) || defined(ANDROID)
#    define MOZILLA_ARM_HAVE_CPUID_DETECTION 1
#  endif

#elif defined(_MSC_VER) && defined(_M_ARM)

#  define MOZILLA_ARM_HAVE_CPUID_DETECTION 1
  // _M_ARM on MSVC has current cpu architecture.
#  define MOZILLA_ARM_ARCH _M_ARM

  // MSVC only allows external asm for ARM, so we don't have to rely on
  // compiler support.
#  define MOZILLA_MAY_SUPPORT_EDSP 1
#  if defined(HAVE_ARM_SIMD)
#    define MOZILLA_MAY_SUPPORT_ARMV6 1
#  endif
#  if defined(HAVE_ARM_NEON)
#    define MOZILLA_MAY_SUPPORT_NEON 1
#  endif

#endif

namespace mozilla {

  namespace arm_private {
#if defined(MOZILLA_ARM_HAVE_CPUID_DETECTION)
#if !defined(MOZILLA_PRESUME_EDSP)
    extern bool NS_COM_GLUE edsp_enabled;
#endif
#if !defined(MOZILLA_PRESUME_ARMV6)
    extern bool NS_COM_GLUE armv6_enabled;
#endif
#if !defined(MOZILLA_PRESUME_NEON)
    extern bool NS_COM_GLUE neon_enabled;
#endif
#endif
  }

#if defined(MOZILLA_PRESUME_EDSP)
#  define MOZILLA_MAY_SUPPORT_EDSP 1
  inline bool supports_edsp() { return true; }
#elif defined(MOZILLA_MAY_SUPPORT_EDSP) \
   && defined(MOZILLA_ARM_HAVE_CPUID_DETECTION)
  inline bool supports_edsp() { return arm_private::edsp_enabled; }
#else
  inline bool supports_edsp() { return false; }
#endif

#if defined(MOZILLA_PRESUME_ARMV6)
#  define MOZILLA_MAY_SUPPORT_ARMV6 1
  inline bool supports_armv6() { return true; }
#elif defined(MOZILLA_MAY_SUPPORT_ARMV6) \
   && defined(MOZILLA_ARM_HAVE_CPUID_DETECTION)
  inline bool supports_armv6() { return arm_private::armv6_enabled; }
#else
  inline bool supports_armv6() { return false; }
#endif

#if defined(MOZILLA_PRESUME_NEON)
#  define MOZILLA_MAY_SUPPORT_NEON 1
  inline bool supports_neon() { return true; }
#elif defined(MOZILLA_MAY_SUPPORT_NEON) \
   && defined(MOZILLA_ARM_HAVE_CPUID_DETECTION)
  inline bool supports_neon() { return arm_private::neon_enabled; }
#else
  inline bool supports_neon() { return false; }
#endif

}

#endif /* !defined(mozilla_arm_h_) */