https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118072
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
COSTS_N_INSNS (6) /* si idiv. */
COSTS_N_INSNS (10) /* di idiv. */
+COSTS_N_INSNS (1)
sdiv is +1
x86_64 generic costs are much higher:
```
{COSTS_N_INSNS (16), /* cost of a divide/mod for QI */
COSTS_N_INSNS (22), /* HI */
COSTS_N_INSNS (30), /* SI */
COSTS_N_INSNS (74), /* DI */
COSTS_N_INSNS (74)}, /* other */
```
It must be that 7 is close to overall cost for the mod case.
So I think using udiv here for the mod is fine.
Integer division on most aarch64 cores is not as expensive as it is on x86.
