c++ - What's the point of logical operators vs. bitwise operators -


given statement logical operation

 ((a > 5) && (b > 4))

and statement bitwise-operation 

   ((a > 5) & (b > 4))

above 2 statements not equivalent.

because (a > 5) element of {0,1}

so, why need logical operators & bitwise-operation?

edit: of feedback. regarding short circuit behaviour of logical operators, not want behaviour - writing code gpu branches degrade performance: short circuit results in 2 branches instead of 1 in code.

for numerical comparisons in c, in case short circuit not needed, seems logical , bitwise have identical behaviour. in case, bitwise ops faster logical.

i apologize not putting these details in original posting.

i think no, take example (0b - means binary):

a = 0b00000010 b = 0b00000100

now, neither a nor b 0. a & b == 0 (due way bitwise , defined).

however a && b != 0 (because logical , result 0 if @ least 1 operand 0 - not case a , b above).

also there short circuit evaluation, if in && left operand 0, right 1 not evaluated because result 0 (e.g., mentioned 0 && x == 0 no matter value of x).


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