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phuclv
phuclv
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Computing the floor of log_2log₂(x) using only bitwise operators in C

For homework, using C, I'm supposed to make a program that finds the log base 2 of a number greater than 0 using only the operators ! ~ & ^ | + << >>! ~ & ^ | + << >>. I know that I'm supposed to shift right a number of times, but I don't know how to keep track of the number of times without having any loops or ifsifs. I've been stuck on this question for days, so any help is appreciated.

int ilog2(int x) {   x = x | (x >> 1); x = x | (x >> 2); x = x | (x >> 4); x = x | (x >> 8); x = x | (x >> 16);   }

This is what I have so far. I pass the most significant bit to the end.

Computing the floor of log_2(x) using only bitwise operators in C

For homework, using C, I'm supposed to make a program that finds the log base 2 of a number greater than 0 using only the operators ! ~ & ^ | + << >>. I know that I'm supposed to shift right a number of times, but I don't know how to keep track of the number of times without having any loops or ifs. I've been stuck on this question for days, so any help is appreciated.

int ilog2(int x) {   x = x | (x >> 1); x = x | (x >> 2); x = x | (x >> 4); x = x | (x >> 8); x = x | (x >> 16);   }

This is what I have so far. I pass the most significant bit to the end.

Computing the floor of log₂(x) using only bitwise operators in C

For homework, using C, I'm supposed to make a program that finds the log base 2 of a number greater than 0 using only the operators ! ~ & ^ | + << >>. I know that I'm supposed to shift right a number of times, but I don't know how to keep track of the number of times without having any loops or ifs. I've been stuck on this question for days, so any help is appreciated.

int ilog2(int x) { x = x | (x >> 1); x = x | (x >> 2); x = x | (x >> 4); x = x | (x >> 8); x = x | (x >> 16); }

This is what I have so far. I pass the most significant bit to the end.

Added work so far.
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Brett Cox
Brett Cox
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For homework, using C, I'm supposed to make a program that finds the log base 2 of a number greater than 0 using only the operators ! ~ & ^ | + << >>. I know that I'm supposed to shift right a number of times, but I don't know how to keep track of the number of times without having any loops or ifs. I've been stuck on this question for days, so any help is appreciated.

int ilog2(int x) { x = x | (x >> 1); x = x | (x >> 2); x = x | (x >> 4); x = x | (x >> 8); x = x | (x >> 16); }

This is what I have so far. I pass the most significant bit to the end.

For homework, using C, I'm supposed to make a program that finds the log base 2 of a number greater than 0 using only the operators ! ~ & ^ | + << >>. I know that I'm supposed to shift right a number of times, but I don't know how to keep track of the number of times without having any loops or ifs. I've been stuck on this question for days, so any help is appreciated.

For homework, using C, I'm supposed to make a program that finds the log base 2 of a number greater than 0 using only the operators ! ~ & ^ | + << >>. I know that I'm supposed to shift right a number of times, but I don't know how to keep track of the number of times without having any loops or ifs. I've been stuck on this question for days, so any help is appreciated.

int ilog2(int x) { x = x | (x >> 1); x = x | (x >> 2); x = x | (x >> 4); x = x | (x >> 8); x = x | (x >> 16); }

This is what I have so far. I pass the most significant bit to the end.

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Brett Cox
Brett Cox
  • 183
  • 1
  • 2
  • 12

Computing the floor of log_2(x) using only bitwise operators in C

For homework, using C, I'm supposed to make a program that finds the log base 2 of a number greater than 0 using only the operators ! ~ & ^ | + << >>. I know that I'm supposed to shift right a number of times, but I don't know how to keep track of the number of times without having any loops or ifs. I've been stuck on this question for days, so any help is appreciated.