Question

D Question 3 12 pts (Important: For this problem, assume that the right-most cell is the low-order value) Assume before the operation the two XMM registers containing the following values XMMO XMMO0 XMM01 XMM02 XMMO3 4.115 -5.65 3.275 2.7 XMM1 ХММ 10 ХММ 11|XMM12XMM13 8.25 15.75 -3.0 22.2 Now suppose the following command is executed: subss xmmO, xmm1 What values will be in XMMO after the instruction finished execution? Answer in decimal. XMM00: XMM01: XMM02: XMM03:

Answer 1

The instruction given in the question is 'subss xmm0, xmm1'.

According to the syntax of this instruction, 'XMM0 register' is the destination and 'XMM1 register' is the source. According to the operation of this instruction, the lowest single-precision floating value of the source register is subtracted from the lowest single-precision floating value of the destination register, and the single-precision floating value result is stored in the destination register at its lowest position. The three higher-order floating point values of the destination register remain unchanged. Hence, only the values of 'XMM03' will change and the values of XMM00, XMM01 and XMM02 will not change and remain as it is. Therefore,

XMM00 = 4.115 (unchanged)

XMM01 = -5.65 (unchanged)

XMM02 = 3.275 (unchanged)

XMM03 = XMM03 - XMM13 = 2.7 - 22.2 = ( -19.5 )