Start by making a copy of this Y$86-64$ example darr from class. Copy$/$paste the contents of the file into this

simulator $G$ to run$/$debug$.$ Run$/$debug the program until you're comfortable with the general structure of the

program, including the main and sum procedures and how they affect registers and memory. In particular, try

making changes to the input array and observing how the output of sum is aggregated in the $\%$rax register using

a loop $($and how the loop keeps track of pointers, indices, etc$).$ Please follow up during office hours or on piazza

with questions! Then...

$(20)$ Add a Y$86-64$ swap procedure equivalent to the following $C$ code. Copy the $C$ code into your Y$86-64$

program as a comment. Assume that $\%$rdi will hold $xp$ and $\%$rsi will hold $yp$ :

void long ${?}^{**}xp,$ long $\{$:${?}^{**}yp)\{$

long $x={?}^{**}xp$;

long $y={?}^{**}yp$;

${?}^{**}xp=y$;

${?}^{**}yp=x$;

$\}$

Comment each line of your Y$86-64$ code in terms of $xp,yp,x,$ and $y.$

$(30)$ Add a Y$86-64$ sort procedure equivalent to the following C code. Copy the C code into your Y$86-64$

program as a comment. Assume that $\%$rdi will hold arr and $\%$rsi will hold length; also assume that this

procedure will call your swap procedure above as appropriate:

void sort$($long $*$arr$,$ long length$)\{$

long $*$iPtr $=$ arr; $//$ pointer to arr$[i]$

for $($long $i=0$;$i$ length $-1$;$++i)\{$

long $*$minPtr $=$ iPtr; $//$ pointer to smallest value found so far in rest of arr

long $**$ jPtr $=$ iPtr $+1\frac{\text{;}}{\frac{?}{?}}$ pointer to arr$[j]$

for $($long $j=i+1$;$j$ length ; $++$j$)\{$

$//$ update minPtr if array $j$ less than value at minPtr

if jptr $<mi\; id="EditorElement\_20670681">*</mi><mi\; id="EditorElement\_20670683">*</mi><mi\; id="EditorElement\_20670685">m</mi><mi\; id="EditorElement\_20670687">i</mi><mi\; id="EditorElement\_20670689">n</mi><mi\; id="EditorElement\_20670691">P</mi><mi\; id="EditorElement\_20670693">t</mi><mi\; id="EditorElement\_20670695">r</mi>$

$\}$

minPtr $=$ jPtr;

$\}$

$++$jPtr; $//$ increment array$[$j$]$ pointer

$//$ swap if a value was found smaller than that at iPtr

if $($minPtr $!=$ iPtr$)\{$

$\}$

swap$($minPtr$,$ iPtr$)$;

$\}$

$++$iPtr; $//$ increment array $[$i$]$ pointer

$\}$