linux - Test_bit macro in C/C++ - Stack Overflow
2018年5月7日 · So, the isolated value may be 1, 2, 4, 8, 16, 32, 64, 128 depending on which bit is tested (the result of 1 << (bit % 8)) if the resp. bit is set. This is not a problem as long as the truth value is needed as everything != 0 is counted as true.
Question about test_bit macro in C - Stack Overflow
2011年9月19日 · Think about what happens when you test a specific bit: 1111 1111 (0xff) & 0000 0100 (0x04, bit 2) ---- ---- = 0000 0100 (0x04) If you left it like that, your result would be the bitmask itself. Now consider the double (logical, not bitwise) negation of that, which is not the same as doing nothing: first: !4 -> 0 then: !0 -> 1 In other words, !!4 gives you 1 rather than 4 and this guarantees ...
C/C++ check if one bit is set in, i.e. int variable
2009年2月7日 · int temp = 0x5E; // in binary 0b1011110. Is there such a way to check if bit 3 in temp is 1 or 0 without bit shifting and masking. Just want to know if there is some built in function for this, o...
x86 - bt assembly instruction - Stack Overflow
2011年9月22日 · will copy bit one of location TestMe+8 into the carry flag. Once again, the size of the operand does not matter. For all intents and purposes, the memory operand is a byte and you can test any bit after that byte with an appropriate index. The actual bit bt tests is at bit position index mod 8 and at memory offset effective address + index/8.
c - what does bit_test () function do? - Stack Overflow
2017年1月1日 · The bit_test() function shifts the test bit to the lowest order position and does a bitwise AND to find if the test bit was set. For example, to test if the bit n = 0 is set for the bit pattern:
How to check if a particular bit is set in C# - Stack Overflow
In C#, I have a 32 bit value which I am storing in an int. I need to see if a particular bit is set. The bit I need is 0x00010000. I came up with this solution: Here is what I am looking for: He...
How do I use the TEST instruction to see if two bits are set?
2020年1月25日 · How could you use the TEST instruction (or a sequence of TEST instructions) to see if bits zero and four in the AL register are both set to one? You can use the Parity Flag trick as in the answer by Aurel Bílý -- though as noted that only works if both bits are in the low 8 bits.
python check if bit in sequence is true or false
2015年2月18日 · I want to find if a bit in a sequense is 1 or 0 (true or false) if i have some bitsequense of 11010011, how can i check if the 4th position is True or False? example: 10010101 (4th bit) -> False
c++ - test_and_set_bit How It Works? - Stack Overflow
2021年7月18日 · If the bit was already 1 does it stay 1 or 0? It will be set to 1 If it's 0 and I'm not wrong then it changes to 1? Yes, it changes to 1 What is "bit" here, an input can be bool which is byte not bit... Bit is one single bit. Not a byte. Input cannot be bool. If you have for example an unsigned char it consists of 8 Bits By return do they mean that after changing the value we change in back to ...
Checking if a bit is set or not - Stack Overflow
2012年1月27日 · Right shift your input n bits down and mask with 1, then test whether you have 0 or 1.