text: /*
   * Copyright 2017-2021 The OpenSSL Project Authors. All Rights Reserved.
   * Copyright 2014 Cryptography Research, Inc.
   *
   * Licensed under the OpenSSL license (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   *
   * Originally written by Mike Hamburg
   */
  
  #include "e_os.h"
  #include <openssl/macros.h>
  #include "internal/numbers.h"
  
  #ifndef UINT128_MAX
  /* No support for 128 bit ints, so do nothing here */
  NON_EMPTY_TRANSLATION_UNIT
  #else
  
  # include "../field.h"
  
  void gf_mul(gf_s * RESTRICT cs, const gf as, const gf bs)
  {
      const uint64_t *a = as->limb, *b = bs->limb;
      uint64_t *c = cs->limb;
      uint128_t accum0 = 0, accum1 = 0, accum2;
      uint64_t mask = (1UI64 << 56) - 1;
      uint64_t aa[4], bb[4], bbb[4];
      unsigned int i, j;
  
      for (i = 0; i < 4; i++) {
          aa[i] = a[i] + a[i + 4];
          bb[i] = b[i] + b[i + 4];
          bbb[i] = bb[i] + b[i + 4];
      }
  
      for (i = 0; i < 4; i++) {
          accum2 = 0;
  
          for (j = 0; j <= i; j++) {
              accum2 += widemul(a[j], b[i - j]);
              accum1 += widemul(aa[j], bb[i - j]);
              accum0 += widemul(a[j + 4], b[i - j + 4]);
          }
          for (; j < 4; j++) {
              accum2 += widemul(a[j], b[i - j + 8]);
              accum1 += widemul(aa[j], bbb[i - j + 4]);
              accum0 += widemul(a[j + 4], bb[i - j + 4]);
          }
  
          accum1 -= accum2;
          accum0 += accum2;
  
          c[i] = ((uint64_t)(accum0)) & mask;
          c[i + 4] = ((uint64_t)(accum1)) & mask;
  
          accum0 >>= 56;
          accum1 >>= 56;
      }
  
      accum0 += accum1;
      accum0 += c[4];
      accum1 += c[0];
      c[4] = ((uint64_t)(accum0)) & mask;
      c[0] = ((uint64_t)(accum1)) & mask;
  
      accum0 >>= 56;
      accum1 >>= 56;
  
      c[5] += ((uint64_t)(accum0));
      c[1] += ((uint64_t)(accum1));
  }
  
  void gf_mulw_unsigned(gf_s * RESTRICT cs, const gf as, uint32_t b)
  {
      const uint64_t *a = as->limb;
      uint64_t *c = cs->limb;
      uint128_t accum0 = 0, accum4 = 0;
      uint64_t mask = (1UI64 << 56) - 1;
      int i;
  
      for (i = 0; i < 4; i++) {
          accum0 += widemul(b, a[i]);
          accum4 += widemul(b, a[i + 4]);
          c[i] = accum0 & mask;
          accum0 >>= 56;
          c[i + 4] = accum4 & mask;
          accum4 >>= 56;
      }
  
      accum0 += accum4 + c[4];
      c[4] = accum0 & mask;
      c[5] += accum0 >> 56;
  
      accum4 += c[0];
      c[0] = accum4 & mask;
      c[1] += accum4 >> 56;
  }
  
  void gf_sqr(gf_s * RESTRICT cs, const gf as)
  {
      const uint64_t *a = as->limb;
      uint64_t *c = cs->limb;
      uint128_t accum0 = 0, accum1 = 0, accum2;
      uint64_t mask = (1UI64 << 56) - 1;
      uint64_t aa[4];
      unsigned int i;
  
      /* For some reason clang doesn't vectorize this without prompting? */
      for (i = 0; i < 4; i++)
          aa[i] = a[i] + a[i + 4];
  
      accum2 = widemul(a[0], a[3]);
      accum0 = widemul(aa[0], aa[3]);
      accum1 = widemul(a[4], a[7]);
  
      accum2 += widemul(a[1], a[2]);
      accum0 += widemul(aa[1], aa[2]);
      accum1 += widemul(a[5], a[6]);
  
      accum0 -= accum2;
      accum1 += accum2;
  
      c[3] = ((uint64_t)(accum1)) << 1 & mask;
      c[7] = ((uint64_t)(accum0)) << 1 & mask;
  
      accum0 >>= 55;
      accum1 >>= 55;
  
      accum0 += widemul(2 * aa[1], aa[3]);
      accum1 += widemul(2 * a[5], a[7]);
      accum0 += widemul(aa[2], aa[2]);
      accum1 += accum0;
  
      accum0 -= widemul(2 * a[1], a[3]);
      accum1 += widemul(a[6], a[6]);
  
      accum2 = widemul(a[0], a[0]);
      accum1 -= accum2;
      accum0 += accum2;
  
      accum0 -= widemul(a[2], a[2]);
      accum1 += widemul(aa[0], aa[0]);
      accum0 += widemul(a[4], a[4]);
  
      c[0] = ((uint64_t)(accum0)) & mask;
      c[4] = ((uint64_t)(accum1)) & mask;
  
      accum0 >>= 56;
      accum1 >>= 56;
  
      accum2 = widemul(2 * aa[2], aa[3]);
      accum0 -= widemul(2 * a[2], a[3]);
      accum1 += widemul(2 * a[6], a[7]);
  
      accum1 += accum2;
      accum0 += accum2;
  
      accum2 = widemul(2 * a[0], a[1]);
      accum1 += widemul(2 * aa[0], aa[1]);
      accum0 += widemul(2 * a[4], a[5]);
  
      accum1 -= accum2;
      accum0 += accum2;
  
      c[1] = ((uint64_t)(accum0)) & mask;
      c[5] = ((uint64_t)(accum1)) & mask;
  
      accum0 >>= 56;
      accum1 >>= 56;
  
      accum2 = widemul(aa[3], aa[3]);
      accum0 -= widemul(a[3], a[3]);
      accum1 += widemul(a[7], a[7]);
  
      accum1 += accum2;
      accum0 += accum2;
  
      accum2 = widemul(2 * a[0], a[2]);
      accum1 += widemul(2 * aa[0], aa[2]);
      accum0 += widemul(2 * a[4], a[6]);
  
      accum2 += widemul(a[1], a[1]);
      accum1 += widemul(aa[1], aa[1]);
      accum0 += widemul(a[5], a[5]);
  
      accum1 -= accum2;
      accum0 += accum2;
  
      c[2] = ((uint64_t)(accum0)) & mask;
      c[6] = ((uint64_t)(accum1)) & mask;
  
      accum0 >>= 56;
      accum1 >>= 56;
  
      accum0 += c[3];
      accum1 += c[7];
      c[3] = ((uint64_t)(accum0)) & mask;
      c[7] = ((uint64_t)(accum1)) & mask;
  
      /* we could almost stop here, but it wouldn't be stable, so... */
  
      accum0 >>= 56;
      accum1 >>= 56;
      c[4] += ((uint64_t)(accum0)) + ((uint64_t)(accum1));
      c[0] += ((uint64_t)(accum1));
  }
  #endif
  