What is happening here in pow function?

Question

I have seen various answer here that depicts Strange behavior of pow function in C.
But I Have something different to ask here.

In the below code I

Answer 1

As others have mentioned, Code 2 returns 99 due to floating point truncation. The reason why Code 1 returns a different and correct answer is because of a libc optimization.

When the power is a small positive integer, it is more efficient to perform the operation as repeated multiplication. The simpler path removes roundoff. Since this is inlined you don't see function calls being made.