Question

ASSEMBLY CODE NEED ASAP WILL RATE RIGHT AWAY

all Verizon 6:48 PM What will r2 contain after the execution of the following instructions assuming that the instructions are executed independently? given that initially r2=0XFFFFFFFF r1=0xFF00FF00 and r0= 0xF7 1) MVN r2, 0x7E000000 2) EOR r2,rO,r1; 3) ROR r2,ro,#2; 4)MLA r2,r2,r2,rO 5) RRX, r2,r& initial carry flag =1 6) MOV r2,(14<<3) 7)ASR r2,r1,#1 8)LSL r2,r1,#3 9) LAR r2,r1,#3

Answer 1

r2 = 0x1C2D3E4F
r1 = 0x83FAC180
r0 = 0xF7

1. MVN r2, 0xFF000000; which means r2 <- NOT 0xFF000000 => r2 <- 0x00FFFFFF.
So, after this instruction r2 will hold, 0x00FFFFFF.

2. RSB r2, r0, 0xFF; Subtracts the value in r0 from the value 0xFF. i.e., r2 <- 0xFF - 0xF7, => r2 <- 0x08.
So, after this instruction r2 will hold, 0x08.

3. ROR r2, r0, #2; Rotates the bits in register r0 by 2 positions and store in r2. i.e., r2 <- 0xF7 rotates by 2 bits.
So, after this instruction r2 will hold, 0xC03D, assuming it to be 16 bit.
If it is 32 bit, then the value in r2 will be 0xC000003D.

4. REVSH r2, r1; Reverses byte order in bottom half word, and sign extend the value in r1.
So, after this instruction r2 will hold, 0x83FA80C1