[Bug tree-optimization/115669] [12/13/14 Regression] rv64gcv/aarch64+sve -fwrapv miscompile since r15-1006-gd93353e6423

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115669

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |15.0
             Status|RESOLVED                    |ASSIGNED
           Priority|P3                          |P2
   Target Milestone|15.0                        |12.5
         Resolution|FIXED                       |---
            Summary|[15 Regression]             |[12/13/14 Regression]
                   |rv64gcv/aarch64+sve -fwrapv |rv64gcv/aarch64+sve -fwrapv
                   |miscompile since            |miscompile since
                   |r15-1006-gd93353e6423       |r15-1006-gd93353e6423

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Let me re-open for backports, the issue is latent with a true SLP reduction.
Unfortunately getting a SLP reduction like the following to work seems
difficult.

int a = 10;
unsigned b, f;
long long c[100];
int main() {
  long long *d = c;
  for (short e = 0; e < a; e++)
    {
      b += ~(d ? d[2*e] : 0);
      f += ~(d ? d[2*e+1] : 0);
    }
  __builtin_printf("%d %d\n", b, f);
}