CareerCup

Looks like a code for a timer to me.
Function waits until the bth bit of a is zero.
a might be an address of program status word or an i/o device address which keeps changing value. If such is true, a should've been defined as volatile.

This piece of code is used to check "If the bth bit is set or not"

There is no return from the function, neither any change in the value for a and b
Therefore this function is useless.

If bth bit is set it goes in infinite loop else it stops. The function does nothing. It returns nothing. Even value of *a does not get changed.

Maybe is used to check for bth bit and works as a wait loop(based on bth bit) before a mutex...where *a gets changed in some other process.

code works to check whether 10^b or 2^b == *a
if true then it breaks otherwise goes into infinite loop.

plz chk my solution.....if have drawn a picture to explain.....excuse for free hand....

it is used to check the validity of input passed to the function.

This code checks, whether pointer to 'a' is 'b' th power of 2, or not.

It is a useless Code.

taking a few binary examples , i guess the code checks if b == a ; since if b equals a , the left shifting and and operation leads to zero as an answer and this takes us to an infinite loop ! but if b !=a the program may continue with execution .

to Know the position of first set bit....i.e. to know the place of 1st occurance of 1
ex:1100==>ans 3
ex:1000==>ans 4

to find whether *a is 2 to the power of sth?