[Bug tree-optimization/94969] [8/9/10/11 Regression] Invalid loop distribution

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94969

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |8.5
           Keywords|                            |wrong-code
   Last reconfirmed|                            |2020-05-06
             Status|UNCONFIRMED                 |NEW
            Summary|Invalid loop distribution   |[8/9/10/11 Regression]
                   |                            |Invalid loop distribution
      Known to work|                            |7.5.0
     Ever confirmed|0                           |1

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  Works fine in GCC 7 which also says

Creating dr for f[pretmp_5].e
analyze_innermost: Applying pattern match.pd:84, generic-match.c:11461
failed: bit offset alignment.
        base_address:
        offset from base address:
        constant offset from base address:
        step:
        aligned to:
        base_object: f
        Access function 0: 7
        Access function 1: pretmp_5

but

(compute_affine_dependence
  stmt_a: f[pretmp_5] = g;
  stmt_b: _2 = f[pretmp_5].e;
) -> dependence analysis failed

instead of

(compute_affine_dependence
  stmt_a: f[pretmp_5] = g;
  stmt_b: _2 = f[pretmp_5].e;
(analyze_overlapping_iterations
  (chrec_a = pretmp_5)
  (chrec_b = pretmp_5)
  (overlap_iterations_a = [0])
  (overlap_iterations_b = [0]))
)