[Bug tree-optimization/89098] ICE: verify_ssa failed (Error: definition in block 27 follows the use)

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89098

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Reproduceable on x86_64-linux with -m32 too.
We have:
  _62 = stride.18_139 * 4;
  _281 = _62 + offset.19_147;
  _63 = stride.18_139 * 5;
  _282 = _63 + offset.19_147;
  _283 = size.20_140 + offset.19_147;
  _486 = stride.18_139 * 6;
  _487 = offset.19_147 + _486;
  _488 = stride.18_139 * 3;
  _489 = offset.19_147 + _488;
  _490 = stride.18_139 * 2;
  _491 = offset.19_147 + _490;
before slsr and slsr changes that into:
  _62 = stride.18_139 * 4;
  _281 = _62 + offset.19_147;
  _63 = stride.18_139 * 5;
  _282 = _281 + stride.18_139;
  slsr_324 = stride.18_139 * 3;
  _283 = _281 + slsr_324;
  _486 = stride.18_139 * 6;
  _487 = _281 + _490;
  _488 = stride.18_139 * 3;
  _489 = _281 - stride.18_139;
  _490 = stride.18_139 * 2;
  _491 = _281 - _490;
and the ICE is because _490 is used before definition.

C testcase that ICEs even on x86_64-linux with -O2 --param
max-slsr-cand-scan=1:
void bar (int, int, int, int, int, int);

int
foo (int s, int o, int x)
{
  int t0 = s * 7;
  if (x)
    {
      int t1 = s * 4;
      int t2 = t1 + o;
      int t3 = s * 5;
      int t4 = t3 + o;
      int t5 = t0 + o;
      int t6 = s * 6;
      int t7 = o + t6;
      int t8 = s * 3;
      int t9 = o + t8;
      int t10 = s * 2;
      int t11 = o + t10;
      bar (t2, t4, t5, t7, t9, t11);
    }
  return t0;
}