/*

   +----------------------------------------------------------------------+

   | Copyright © The PHP Group and Contributors.                          |

   +----------------------------------------------------------------------+

   | This source file is subject to the Modified BSD License that is      |

   | bundled with this package in the file LICENSE, and is available      |

   | through the World Wide Web at <https://www.php.net/license/>.        |

   |                                                                      |

   | SPDX-License-Identifier: BSD-3-Clause                                |

   +----------------------------------------------------------------------+

   | Author: Rasmus Lerdorf <rasmus@php.net>                              |

   +----------------------------------------------------------------------+

*/

#include "php.h"

#include "crc32.h"

#include "crc32_x86.h"

#ifdef HAVE_AARCH64_CRC32

#ifndef PHP_WIN32

# include <arm_acle.h>

#endif

# if defined(__linux__)

#  include <sys/auxv.h>

#  include <asm/hwcap.h>

# elif defined(__APPLE__)

#  include <sys/sysctl.h>

# elif defined(HAVE_ELF_AUX_INFO)

#  include <sys/auxv.h>

static unsigned long getauxval(unsigned long key) {

  unsigned long ret = 0;

  if (elf_aux_info(key, &ret, sizeof(ret)) != 0)

    return 0;

  return ret;

}

# endif

static inline int has_crc32_insn(void) {

  /* Only go through the runtime detection once. */

  static int res = -1;

  if (res != -1)

    return res;

# if defined(HWCAP_CRC32)

  res = getauxval(AT_HWCAP) & HWCAP_CRC32;

  return res;

# elif defined(HWCAP2_CRC32)

  res = getauxval(AT_HWCAP2) & HWCAP2_CRC32;

  return res;

# elif defined(__APPLE__)

  size_t reslen = sizeof(res);

  if (sysctlbyname("hw.optional.armv8_crc32", &res, &reslen, NULL, 0) < 0)

    res = 0;

  return res;

# elif defined(_WIN32)

  res = (int)IsProcessorFeaturePresent(PF_ARM_V8_CRC32_INSTRUCTIONS_AVAILABLE);

  return res;

# else

  res = 0;

  return res;

# endif

}

# if defined(__GNUC__)

#  if!defined(__clang__)

#   pragma GCC push_options

#   pragma GCC target ("+nothing+crc")

#  elif defined(__APPLE__)

#   pragma clang attribute push(__attribute__((target("crc"))), apply_to=function)

#  else

#   pragma clang attribute push(__attribute__((target("+nothing+crc"))), apply_to=function)

#  endif

# endif

static uint32_t crc32_aarch64(uint32_t crc, const char *p, size_t nr) {

  while (nr >= sizeof(uint64_t)) {

    crc = __crc32d(crc, *(uint64_t *)p);

    p += sizeof(uint64_t);

    nr -= sizeof(uint64_t);

  }

  if (nr >= sizeof(int32_t)) {

    crc = __crc32w(crc, *(uint32_t *)p);

    p += sizeof(uint32_t);

    nr -= sizeof(uint32_t);

  }

  if (nr >= sizeof(int16_t)) {

    crc = __crc32h(crc, *(uint16_t *)p);

    p += sizeof(uint16_t);

    nr -= sizeof(uint16_t);

  }

  if (nr) {

    crc = __crc32b(crc, *p);

  }

  return crc;

}

# if defined(__GNUC__)

#  if !defined(__clang__)

#   pragma GCC pop_options

#  elif defined(__APPLE__)

#   pragma clang attribute pop

#  else

#   pragma clang attribute pop

#  endif

# endif

#endif

PHPAPI uint32_t php_crc32_bulk_update(uint32_t crc, const char *p, size_t nr)

{

#ifdef HAVE_AARCH64_CRC32

  if (has_crc32_insn()) {

    crc = crc32_aarch64(crc, p, nr);

    return crc;

  }

#endif

#if defined(ZEND_INTRIN_SSE4_2_PCLMUL_NATIVE) || defined(ZEND_INTRIN_SSE4_2_PCLMUL_RESOLVER)

  size_t nr_simd = crc32_x86_simd_update(X86_CRC32B, &crc, (const unsigned char *)p, nr);

  nr -= nr_simd;

  p += nr_simd;

#endif

  /* The trailing part */

  for (; nr--; ++p) {

    crc = ((crc >> 8) & 0x00FFFFFF) ^ crc32tab[(crc ^ (*p)) & 0xFF ];

  }

  return crc;

}

PHPAPI zend_result php_crc32_stream_bulk_update(uint32_t *crc, php_stream *fp, size_t nr)

{

  size_t handled = 0, n;

  char buf[1024];

  while (handled < nr) {

    n = nr - handled;

    n = (n < sizeof(buf)) ? n : sizeof(buf); /* tweak to buf size */

    n = php_stream_read(fp, buf, n);

    if (n > 0) {

      *crc = php_crc32_bulk_update(*crc, buf, n);

      handled += n;

    } else { /* EOF */

      return FAILURE;

    }

  }

  return SUCCESS;

}

/* {{{ Calculate the crc32 polynomial of a string */

PHP_FUNCTION(crc32)

{

  char *p;

  size_t nr;

  uint32_t crc = php_crc32_bulk_init();

  ZEND_PARSE_PARAMETERS_START(1, 1)

    Z_PARAM_STRING(p, nr)

  ZEND_PARSE_PARAMETERS_END();

  crc = php_crc32_bulk_update(crc, p, nr);

  RETURN_LONG(php_crc32_bulk_end(crc));

}

/* }}} */