CS计算机代考程序代写 .file “lab5.s”
.file “lab5.s”
.globl main
.type main, @function
.text
main:
pushq %rbp #stack housekeeping
movq %rsp, %rbp
Label1:
#as you go through this program note the changes to %rip
movq $0x8877665544332211, %rax # the value of %rax is:
# Recall that -1 is represented as 0xff, 0xffff, etc. depending upon the size of the value
movb $-1, %al # the value of %rax is:
movw $-1, %ax # the value of %rax is:
movl $-1, %eax # the value of %rax is:
movq $-1, %rax # the value of %rax is:
movl $-1, %eax # the value of %rax is:
cltq # the value of %rax is:
movl $0x7fffffff, %eax # the value of %rax is:
cltq # the value of %rax is:
movl $0x8fffffff, %eax # the value of %rax is:
cltq # the value of %rax is:
# what do you think the cltq instruction does?
movq $0x8877665544332211, %rax # the value of %rax is:
# the value of %rdx *before* movb $0xAA, %dl executes is:
# Note the value of the 8-byte register values vs the 1, 2, or 4-byte register values
# How does each size instruction suffix affect the 8-byte register? Don’t write answers here; you’ll need this info later.
movb $0xAA, %dl # the value of %rdx is:
movb %dl, %al # the value of %rax is:
movsbw %dl, %ax # the value of %rax is:
movzbw %dl, %ax # the value of %rax is:
movq $0x8877665544332211, %rax # the value of %rax is:
movb %dl, %al # the value of %rax is:
movsbl %dl, %eax # the value of %rax is:
movzbl %dl, %eax # the value of %rax is:
movq $0x8877665544332211, %rax # the value of %rax is:
movb %dl, %al # the value of %rax is:
movsbq %dl, %rax # the value of %rax is:
movzbq %dl, %rax # the value of %rax is:
movq $0x8877665544332211, %rax # the value of %rax is:
# the value of %rdx *before* movb $0x55, %dl executes is:
movb $0x55, %dl # the value of %rdx is:
movb %dl, %al # the value of %rax is:
movsbw %dl, %ax # the value of %rax is:
movzbw %dl, %ax # the value of %rax is:
movq $0x8877665544332211, %rax # the value of %rax is:
movb %dl, %al # the value of %rax is:
movsbl %dl, %eax # the value of %rax is:
movzbl %dl, %eax # the value of %rax is:
movq $0x8877665544332211, %rax # the value of %rax is:
movb %dl, %al # the value of %rax is:
movsbq %dl, %rax # the value of %rax is:
movzbq %dl, %rax # the value of %rax is:
# movq $0x8877665544332211, %rax
# pushb %al
# movq $0, %rax
# popb %al
movq $0x8877665544332211, %rax # the value of %rax is: the value of %rsp is:
pushw %ax # the value of %rsp is:
# the difference between the two values of %rsp is:
movq $0, %rax # the value of %rax is:
popw %ax # the value of %rax is: How did the value of %rsp change?
movq $0x8877665544332211, %rax # the value of %rax is: the value of %rsp is:
pushw %ax # the value of %rsp is:
# the difference between the two values of %rsp is:
movq $-1, %rax # the value of %rax is:
popw %ax # the value of %rax is: How did the value of %rsp change?
# movq $0x8877665544332211, %rax
# pushl %eax
# movq $0, %rax
# popl %eax
movq $0x8877665544332211, %rax # the value of %rax is: the value of %rsp is:
pushq %rax # the value of %rsp is:
# the difference between the two values of %rsp is:
movq $0, %rax # the value of %rax is:
popq %rax # the value of %rax is: How did the value of %rsp change?
# what rflags are set?
movq $0x500, %rax # the value of %rax is:
movq $0x123, %rcx # the value of %rcx is:
# 0x123 – 0x500
subq %rax, %rcx # the value of %rax is:
# the value of %rcx is:
# what rflags are set?
movq $0x500, %rax # the value of %rax is:
movq $0x123, %rcx # the value of %rcx is:
# 0x500 – 0x123
subq %rcx, %rax # the value of %rax is:
# what rflags are set?
movq $0x500, %rax # the value of %rax is:
movq $0x500, %rcx # the value of %rcx is:
# 0x500 – 0x500
subq %rcx, %rax # the value of %rax is:
# what rflags are set?
movb $0xff, %al # the value of %rax is:
# 0xff +=1 (1 byte)
incb %al # the value of %rax is: what rflags are set?
movb $0xff, %al # the value of %rax is:
# 0xff +=1 (4 bytes)
incl %eax # the value of %rax is: what rflags are set?
movq $-1, %rax # the value of %rax is:
# 0xff +=1 (8 bytes)
incq %rax # the value of %rax is: what rflags are set?
movq $0x8877665544332211, %rax # the value of %rax is:
movq $0x8877665544332211, %rcx # the value of %rax is: what rflags are set?
addq %rcx, %rax # the value of %rax is: what rflags are set?
movq $0x8877665544332211, %rax # the value of %rax is:
andq $0x1, %rax # the value of %rax is:
movq $0x8877665544332211, %rax # the value of %rax is: explain why the values for AND/OR/XOR are
andq %rax, %rax # the value of %rax is: what they are
orq %rax, %rax # the value of %rax is:
xorq %rax, %rax # the value of %rax is:
movq $0x8877665544332211, %rax # the value of %rax is:
andw $0x3300, %ax # the value of %rax is: explain the value in the 8 byte register vs
#the value in the 2 byte register
salq $4, %rax # the value of %rax is: Why?
movq $0xff0000001f000000, %rax # the value of %rax is: to help you understand what’s happening in this part of the code, write the value in %rax in binary
# on a piece of scratch paper for the remaining instructions in this file
# and watch the bits move as each shift instruction occurs.
# You should notice how each of the 1-, 2-, 4-, and 8-byte shift instructions works
# within the 8-byte register.
sall $1, %eax # the value of %rax is: do these shift instructions do what you expected?
sall $1, %eax # the value of %rax is:
sall $1, %eax # the value of %rax is:
sall $1, %eax # the value of %rax is:
sall $1, %eax # the value of %rax is:
movq $0xff000000ff000000, %rax # the value of %rax is:
salq $1, %rax # the value of %rax is:
salq $1, %rax # the value of %rax is:
salq $1, %rax # the value of %rax is:
salq $1, %rax # the value of %rax is:
salq $1, %rax # the value of %rax is:
movq $0xff000000000000ff, %rax # the value of %rax is:
sarq $1, %rax # the value of %rax is:
sarq $1, %rax # the value of %rax is:
sarq $1, %rax # the value of %rax is:
sarq $1, %rax # the value of %rax is:
sarq $1, %rax # the value of %rax is:
movq $0xff000000000000ff, %rax # the value of %rax is:
shrq $1, %rax # the value of %rax is:
shrq $1, %rax # the value of %rax is:
shrq $1, %rax # the value of %rax is:
shrq $1, %rax # the value of %rax is:
shrq $1, %rax # the value of %rax is:
movq $0xff000000000000ff, %rax # the value of %rax is:
sarw $1, %ax # the value of %rax is:
sarw $1, %ax # the value of %rax is:
sarw $1, %ax # the value of %rax is:
sarw $1, %ax # the value of %rax is:
sarw $1, %ax # the value of %rax is:
movq $0xff000000000000ff, %rax # the value of %rax is:
shrw $1, %ax # the value of %rax is:
shrw $1, %ax # the value of %rax is:
shrw $1, %ax # the value of %rax is:
shrw $1, %ax # the value of %rax is:
shrw $1, %ax # the value of %rax is:
leave #post function stack cleanup
ret
.size main, .-main
