[Bug tree-optimization/111879] New: No gather BB vectorization for

[Bug tree-optimization/111879] New: No gather BB vectorization for

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111879

            Bug ID: 111879
           Summary: No gather BB vectorization for
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org
  Target Milestone: ---

void __attribute__((noipa))
f (int *restrict y, int *restrict x, int *restrict indices)
{     
  int i = 0;
  y[i * 2] = x[indices[i * 2]] + 1;
  y[i * 2 + 1] = x[indices[i * 2 + 1]] + 2;
  i++;
  y[i * 2] = x[indices[i * 2]] + 1;
  y[i * 2 + 1] = x[indices[i * 2 + 1]] + 2;
  i++;
  y[i * 2] = x[indices[i * 2]] + 1;
  y[i * 2 + 1] = x[indices[i * 2 + 1]] + 2;
  i++;
  y[i * 2] = x[indices[i * 2]] + 1;
  y[i * 2 + 1] = x[indices[i * 2 + 1]] + 2;
}   

doesn't see the gather operation vectorized (extracted from the loop in
gcc.dg/vect/vect-gather-1.c).  Instead we only see the adds and the stores
vectorized.

[Bug tree-optimization/111879] No gather BB vectorization for

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111879

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
   Last reconfirmed|                            |2023-10-19
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
The way we identify gathers/scatters in vect_analyze_data_refs doesn't work.
We probably have to delay gather/scatter "discovery" until after we do
group analysis or within that.

So it's not going to be simple.