signed/unsigned min/max gives more flexibility.
```
-uint_xlen_t min(uint_xlen_t rs1, uint_xlen_t rs2)
+uint_xlen_t mins(uint_xlen_t rs1, uint_xlen_t rs2)
{ return (int_xlen_t)rs1 < (int_xlen_t)rs2 ? rs1 : rs2;
}
-uint_xlen_t max(uint_xlen_t rs1, uint_xlen_t rs2)
+uint_xlen_t maxs(uint_xlen_t rs1, uint_xlen_t rs2)
{ return (int_xlen_t)rs1 > (int_xlen_t)rs2 ? rs1 : rs2;
}
uint_xlen_t minu(uint_xlen_t rs1, uint_xlen_t rs2)