Golang位只使用无符号？

This is a java function, i converted to golang code, but appear error.
How can I solve this problem? please teach.

java code:

int p = -1;
int x = 0;
x |= 0x1 << p;
p++;

golang code:

var p int = -1
var x int = 0
x |= 0x1 << p
p++

shift code type int, must be unsigned integer

This is an error because as per Go specifications, bit shifting only works on unsigned ints:

left shift             integer << unsigned integer
right shift            integer >> unsigned integer