[Bug tree-optimization/113783] ICE: in lower_stmt, at gimple-lower-bitint.cc:5455 with -O -mavx512f and _BitInt() in memcpy()

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113783

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Ugh, folding turns this into
  uint256_t D.3758;

  <bb 2> :
  D.3758 = MEM <uint256_t> [(char * {ref-all})&x];
  MEM <uint256_t> [(char * {ref-all})p] = D.3758;
and later ssa turns it into
  uint256_t _2;

  <bb 2> :
  _2 = VIEW_CONVERT_EXPR<uint256_t>(x_1(D));
  MEM <uint256_t> [(char * {ref-all})p_4(D)] = _2;
where presumably uint256_t is some 256-bit unsigned INTEGER_TYPE.
Except it isn't really supported except perhaps for moves.

Similarly
void
bar (void *p, _BitInt(502) x)
{
  __builtin_memcpy (p, &x, sizeof x);
}
into
  uint512_t D.3758;

  D.3758 = MEM <uint512_t> [(char * {ref-all})&x];
  MEM <uint512_t> [(char * {ref-all})p] = D.3758;
and later
  uint512_t _2;

  <bb 2> :
  _2 = VIEW_CONVERT_EXPR<uint512_t>(x_1(D));
  MEM <uint512_t> [(char * {ref-all})p_4(D)] = _2;


I don't see how I could handle that in bitint lowering when shifts,
BIT_IOR_EXPR etc.
will not work on such types.