Write ARM code to implement the following C operation.

int s = 0;

for ( i = 0; i < 10; i++) {

s = s + i*i;)

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AREA SumSquares, code, readwrite

ENTRY

MOV r0,#0 ;loop counter i preset to 0

MOV r1,#0 ;s = 0

Loop MUL r2,r0,r0 ;calc i*i

ADD r1,r1,r2 ;s = s + i*i

ADDS r0,r0,#1 ;i = i + i

CMP r0,#10 ;test for end

BNE Loop ;continue until all added

END

We can improve this code by counting down rather than up to remove the comparison. We can also use the
multiply and accumulate operation to perform the i2 and addition.

AREA SumSquares2, code, readwrite

ENTRY

MOV r0,#9 ;loop counter i preset to 9

MOV r1,#0 ;s = 0

Loop MLA r1,r0,r0,r1 ;calc i*i

SUBS r0,r0,#1 ;i = i - i

BNE Loop ;continue until all added

END