[Bug target/108787] [13 Regression] libsodium miscompilation on power9 starting with r13-2107

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108787

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Correction, -fPIC isn't important.  Even more reduced testcase:
__attribute__((noipa)) unsigned __int128
foo (unsigned long long h0, unsigned long long h1, unsigned long long h2,
unsigned long long r0, unsigned long long s1, unsigned long long s2)
{
  unsigned __int128 d0, d;
  d0 = ((unsigned __int128) h0 * r0);
  d = ((unsigned __int128) h1 * s2);
  d0 += d;
  d = ((unsigned __int128) h2 * s1);
  d0 += d;
  return d0;
}

int
main ()
{
  if (__CHAR_BIT__ != 8 || __SIZEOF_LONG_LONG__ != 8 || __SIZEOF_INT128__ !=
16)
    return 0;
  unsigned __int128 x = foo (0x3efe88da491ULL, 0xd105e9b4a44ULL,
0x4efa677b3dbULL, 0x42c052bac7bULL, 0x99638a13199cULL, 0x56b640d064ULL);
  if ((unsigned long long) (x >> 64) != 0x000000000309ff93ULL
      || (unsigned long long) x != 0xbd5c98fdf2bdbcafULL)
    __builtin_abort ();
  return 0;
}

The high 64-bits of the result are miscomputed.