error C2059: 语法错误 : “数字上的错误后缀”

遇到这么一段代码,提示rt错误,vs2005能编译通过,2002编译就上面的错误,在有"0xffffffff80000000LL"的行,不知道后面的LL什么意思,求解.signed _int64 tmp = (signed _int64)lhs * (signed _int64)rhs; //upper 33 bits must be the same
//most common case is likely that both are positive - test first
if( (tmp & 0xffffffff80000000LL) == 0 ||
(tmp & 0xffffffff80000000LL) == 0xffffffff80000000LL)
{
//this is OK
return (T)tmp;
}