Figure 3.54(a) shows the code for a function that is similar to function vfunct (Figure...

Figure 3.54(a) shows the code for a function that is similar to function vfunct (Figure 3.43(a)). We used vfunct to illustrate the use of a frame pointer in man-aging variable-size stack frames. The new function aframe allocates space for local

array p by calling library function alloca. This function is similar to the more commnonly used function manoc, except that it allocates space on the run-time stack. The space is automatically deallocated when the executing procedure returns.

Figure 3.54(b) shows the part of the assembly code that sets up the frame pointer and allocates space for local variables i and p. It is very similar to the corresponding code for vframe .Let us use the same notation as in Problem 3.49: The stack pointer is set to values s₁ at line 4 and s₂ at line 7. The start address of array p is set to value p at line 9. Extra space e₂ may arise between s₂ and p, and extra space e₁ may arise between the end of array p and s₁.

A. Explain, in mathematical terms, the logic in the computation of s₂.

B. Explain, in mathematical terms, the logic in the computation of p.

C. Find values of n and si that lead to minimum and maximum values of e₁.

D. What alignment properties does this code guarantee for the values of s₂ and p?