[Bug tree-optimization/122855] [16 regression] ICE when building mupdf-1.26.3 (build_vector_from_val, at tree.cc:2245)

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122855

--- Comment #3 from Sam James <sjames at gcc dot gnu.org> ---
```
char *__restrict zoom_x3_tmp;
int zoom_x3_weights_0, zoom_x3_j, zoom_x3_pixel2;

void zoom_x3() {
  char *s;
  int pixel0 = 0, pixel1 = 0;
  for (; zoom_x3_j; zoom_x3_j--) {
    pixel0 += *s++ * zoom_x3_weights_0;
    pixel1 += *s++ * zoom_x3_weights_0;
    zoom_x3_pixel2 += *s++ * zoom_x3_weights_0;
  }
  *zoom_x3_tmp++ = pixel0 < 0 ? 0 : pixel0 > 255 ? 255 : pixel0;
  *zoom_x3_tmp = pixel1 < 0 ? 0 : pixel1 > 255 ? 255 : pixel1;
}
```

I haven't been able to fix the uninit use of s yet.