bit

问题 I am not sure of the precise definition of this term. I know that a bitwise XOR operation is going bit by bit and taking the XOR of corresponding bits position wise. Is this result termed the 'XOR sum'? If not, what is an XOR sum, and how do you use XOR to implement this addition? 回答1: In a bit wise XOR operation: a b a^b ----------- 0 0 0 0 1 1 1 0 1 1 1 0 XOR sum refers to successive XOR operations on integers. Suppose you have numbers from 1 to N and you have to find their XOR sum then for

问题 All I need to off the rightmost set bit. My approach is to find the position of right most bit, then off that bit. I write this code to do so.. int POS(int n) { int p=0; while(n) { if(n%2==0) { p++; } else { break; } n=n/2; } return p; } int main(void) { int n=12; int p = POS(n); printf("%d \n", n&~(1<<p)); return 0; } Is there any simplest way? 回答1: Read http://www.geeksforgeeks.org/turn-off-the-rightmost-set-bit/ /* unsets the rightmost set bit of n and returns the result */ int fun

问题 I have table with some fields that the value will be 1 0. This tables will be extremely large overtime. Is it good to use bit datatype or its better to use different type for performance? Of course all fields should be indexed. 回答1: Officially bit will be fastest, especially if you don't allow nulls. In practice it may not matter, even at large usages. But if the value will only be 0 or 1, why not use a bit? Sounds like the the best way to ensure that the value won't get filled with invalid

问题 I have table with some fields that the value will be 1 0. This tables will be extremely large overtime. Is it good to use bit datatype or its better to use different type for performance? Of course all fields should be indexed. 回答1: Officially bit will be fastest, especially if you don't allow nulls. In practice it may not matter, even at large usages. But if the value will only be 0 or 1, why not use a bit? Sounds like the the best way to ensure that the value won't get filled with invalid

问题 I have table with some fields that the value will be 1 0. This tables will be extremely large overtime. Is it good to use bit datatype or its better to use different type for performance? Of course all fields should be indexed. 回答1: Officially bit will be fastest, especially if you don't allow nulls. In practice it may not matter, even at large usages. But if the value will only be 0 or 1, why not use a bit? Sounds like the the best way to ensure that the value won't get filled with invalid

问题 I know in most, if not all programming languages, integers, floats etc all have a maximum amount they can hold, either unsigned or signed. Eg pascal's int type can only hold up to 32768 ~. What i wanted to know was, what is the limit on python's int and floating point variables. I tried a little program to produce extremely large numbers, but i ran into no errors. Does it even have limits on how big these variables can be ? I looked in the documentation and couldn't find what i was looking

问题 I know in most, if not all programming languages, integers, floats etc all have a maximum amount they can hold, either unsigned or signed. Eg pascal's int type can only hold up to 32768 ~. What i wanted to know was, what is the limit on python's int and floating point variables. I tried a little program to produce extremely large numbers, but i ran into no errors. Does it even have limits on how big these variables can be ? I looked in the documentation and couldn't find what i was looking

来源： https://stackoverflow.com/questions/45964607/quadrature-signal-generation-with-bit-manipulation

来源： https://stackoverflow.com/questions/45964607/quadrature-signal-generation-with-bit-manipulation

来源： https://stackoverflow.com/questions/64477750/treating-assembly-registers-as-unsigned-vs-signed