[Bug tree-optimization/114396] [13/14 Regression] Vector: Runtime mismatch at -O2 with -fwrapv since r13-7988-g82919cf4cb2321

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114396

--- Comment #17 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
> > 
> > The to_mpz args look like they could be mixing signs as well:
> > 
I tries below, looks like mixing signs works well.
debug show step_expr is -5 and signed.

short a = 0xF;
short b[16];
unsigned short ua = 0xF;
unsigned short ub[16];

int main() {
  for (int e = 0; e < 9; e += 1)
    b[e] = a *= 0x5;
  __builtin_printf("decimal: %d\n", a);
  __builtin_printf("hex: %X\n", a);

  for (int e = 0; e < 9; e += 1)
    b[e] = a *= -5;
  __builtin_printf("decimal: %d\n", a);
  __builtin_printf("hex: %X\n", a);

  for (int e = 0; e < 9; e += 1)
    ub[e] = ua *= 0x5;
  __builtin_printf("decimal: %d\n", ua);
  __builtin_printf("hex: %X\n", ua);

  for (int e = 0; e < 9; e += 1)
    ub[e] = ua *= -5;
  __builtin_printf("decimal: %d\n", ua);
  __builtin_printf("hex: %X\n", ua);

}