MMX v/s SSE2 Performance Comparison

gistfile1.asm

.model C,flat

.data

.code

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;
;  			MMX ASSEMBLY
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

euclidean_MMX proc
  mov eax,[esp+1*4]	; x_ptr in eax
	mov ebx,[esp+2*4]	; y_ptr in ebx
	mov ecx,[esp+3*4]	; counter in ecx
	shr ecx,3;        ; divide counter by 8

	pxor mm7,mm7				; clear mm7 to store 0

	MainLoop:
	;
	; First find X^2
	;
	movq mm0,qword ptr[eax]		; 8 bytes from EAX
	movq mm1,mm0				; make a copy of mm0

	punpckhbw mm1,mm7			; convert B -> W for upper half
	pmullw mm1,mm1				; square and keep the lower order

	punpcklbw mm0,mm7			; convert B -> W for lower half
	pmullw mm0,mm0				; square and keep the lower order
	
	packuswb mm0,mm1			; pack words into bytes
								        ; mm0 has X2

    	;
    	;Now Find Y^2
    	;
	movq mm1,qword ptr[ebx]		; 8 bytes from EAX
	movq mm2,mm1				; make a copy of mm1

	punpckhbw mm2,mm7			; convert B -> W for upper half
	pmullw mm2,mm2				; square and keep the lower order

	punpcklbw mm1,mm7			; convert B -> W for lower half
	pmullw mm1,mm1				; square and keep the lower order
	
	packuswb mm1,mm2			; pack words into bytes
								        ; mm1 has Y^2

	; Now add them
	paddb mm0,mm1				; z2 = x2+y2
	movq [eax],mm0				; store back the results
	add eax,8					; move eax by 8 bytes
	add ebx,8					; move ebx by 8 bytes
	dec ecx
	jnz MainLoop
	
	emms
	ret
euclidean_MMX endp


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;
;				SSE2 ASSEMBLY
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

euclidean_SSE proc
	mov eax,[esp+1*4]	; x_ptr in eax
	mov ebx,[esp+2*4]	; y_ptr in ebx
	mov ecx,[esp+3*4]	; counter in ecx
	shr ecx,4         ; divide counter by 16

	pxor xmm7,xmm7				; clear mm7 to store 0

	MainLoop:
	;
	; First do with X vector
	;
	movdqa xmm0,xmmword ptr[eax]; 16 bytes from EAX
	movdqa xmm1,xmm0			; make a copy of xmm0

	punpckhbw xmm1,xmm7			; convert B -> W for upper half
	pmullw xmm1,xmm1			; square and keep the lower order

	punpcklbw xmm0,xmm7			; convert B -> W for lower half
	pmullw xmm0,xmm0			; square and keep the lower order
	
	packuswb xmm0,xmm1			; pack words into bytes
								        ; xmm0 has X2

	;
	;Now with Y vector
	;
	movdqa xmm1,xmmword ptr[ebx]; 8 bytes from EAX
	movdqa xmm2,xmm1			; make a copy of mm0

	punpckhbw xmm2,xmm7			; convert B -> W for upper half
	pmullw xmm2,xmm2			; square and keep the lower order

	punpcklbw xmm1,xmm7			; convert B -> W for lower half
	pmullw xmm1,xmm1			; square and keep the lower order
	
	packuswb xmm1,xmm2			; pack words into bytes
								          ; mm1 has Y2

	; Now add them
	paddb xmm0,xmm1				; z2 = x2+y2
	movdqa [eax],xmm0			; store back the results
	add eax,16					; move eax by 16 bytes
	add ebx,16					; move ebx by 16 bytes
	dec ecx
	jnz MainLoop
	
	emms
	ret
euclidean_SSE endp
end