Why is abs(0x80000000) == 0x80000000?

Question

I just started reading Hacker\'s Delight and it defines abs(-2³¹) as -2³¹. Why is that?

I tried printf(\"%x\", abs(0x80000000)) on a f

Answer 1

I think the way abs works is to first check the sign bit of the number. If its clear do nothing as the number is already +ve else return the 2's complement of the number. In your case the number is -ve and we need to find its 2's complement. But 2's complement of 0x80000000 happens to be 0x80000000 itself.