A single CALL instruction on the x86 does a very limited amount: it pushes the address of the next instruction onto the stack, and then it sets the instruction

A single CALL instruction on the x86 does a very limited amount: it pushes the address of the next instruction onto the stack, and then it sets the instruction pointer to the thing that was called. What happens next is up to the function and not part of the CALL instruction. Allocate and free are perfectly reasonable terms to describe the use of a pool too.