int mat$1[$ M $][$ N $]$;

int mat$2[$ N $][$ M $]$;

int sum$\_$element $($int i $,$ int j $)$

$\{$

return mat$1[$ i $][$ j $]+$ mat$2[$ i $][$ j $]$;

$\}$

Suppose the above code generates the following assembly code:

; on entry $,$ i is in $\%$ edi $,$ j is in $\%$ esi

; movslq converts long to quad

; leaq offset $($ R$1,$ R$2,$ I $)$ computes address I $*$ R$2+$ R$1+$ offset

; sal is a shift left

sum$\_$element :

movslq $\%$ esi $,\%$ rsi

movslq $\%$ edi $,\%$ rdi

leaq $(\%$ rdi $,\%$ rdi $,4),\%$ rax

leaq $(\%$ rdi $,\%$ rax $,2),\%$ rdx

addq $\%$ rsi $,\%$ rdx

leaq $(\%$ rdi $,\%$ rdi $,2),\%$ rcx

movq $\%$ rcx $,\%$ rax

salq $$4,\%$ rax

subq $\%$ rdi $,\%$ rax

addq $\%$ rsi $,\%$ rax

movl mat$2(,\%$ rax $,4),\%$ eax

addl mat$1(,\%$ rdx $,4),\%$ eax

ret

$(1)$ What is the value of M$?$

$(2)$ What is the value of N$?$

$(3)$ Due to a bug, the program tried to reference mat$1[3][-9].$ Which element of mat$1$ will

actually be accessed?