Mips和cisc汇编语言

Question

does anyone have a simple program with source code run in both assembly langue mips and cisc to explan mips run with less cpu cycle than cisc ?

simple program do not require large one

thank you

Answer 1

A simple example would be the comparing two strings against each others:

MIPS

; string pointers in $a0 and $a1
more:
  ld $r0,($a0)
  ld $r1,($a1)
  add 1, $a0
  add 1, $a1
  cmp $r0,$0
  je eos
  cmp $r1,$0
  je eos
  cmp $r0,$r1
  je more
eos:
  cmp $r0, $r1
; cmp result defines whether a0 < a1, a0 == a1, a0 > a1

CISC (Intel)

; start with strings in edi and esi
more:
  cmps (edi), (esi)
  loopnz more
; cmps result defines whether a0 < a1, a0 == a1, a0 > a1

I do not guarantee the validity of this code. However, we can see that the CISC does the same thing as the MIPS in 2 instructions (although initialization may require more code in CISC...). However, they are likely taking about the same amount of time.