AMD 250 manual 234

Software Optimization Guide for AMD64 Processors 25112 Rev. 3.06 September 2005

;THE 4 ASM LINES BELOW LOAD THE FUNCTION’S ARGUMENTS INTO GENERAL-PURPOSE

;REGISTERS (GPRs)

;eax = address of Transposed Rotation Matrix

;edx = address of vertices to rotate

;ecx = # of vertices to rotate

;ebx = address of rotated vertices ;==============================================================================

mov eax, [ebp+8]	; ESI =	->R
mov edx, [ebp+12]	; EDI =	->v
mov ecx, [ebp+16]	; ECX =	num_vertices_to_rotate
mov ebx, [ebp+20]	; EAX =	->rotv
femms	; Clear	MMX state.
ALIGN 16	; Ensure optimal branch alignment.

;==============================================================================

;THIS LOOP ROTATES "num_vertices_to_rotate" VERTICES BY THE TRANSPOSED

;ROTATION MATRIX "R" PASSED INTO THE ROUTINE AND STORES THE ROTATED

;VERTICES TO "rotv". ;============================================================================== rotate_vertices_loop:

add	ebx,16	; Increment ->v to next vertex.
movq	mm0,[edx]	; MM0 = [y,x]
movq	mm1,[edx+8]	; MM1 = [w,z]
add	edx,16	; Increment ->rotv to next transformed vertex.
movq	mm2,mm0	; MM2 = [y,x]
movq	mm3,[eax]	; MM3 = [R01,R00]
punpckldq	mm0,mm0	; MM0 = [x,x]
movq	mm4,[eax+16]	; MM4 = [R11,R10]
pfmul	mm3,mm0	; MM3 = [x*R01,x*R00]
punpckhdq	mm2,mm2	; MM2 = [y,y]
pfmul	mm4,mm2	; MM4 = [y*R11,y*R10]
movq	mm5,[eax+8]	; MM5 = [R03,R02]
movq	mm7,[eax+24]	; MM7 = [R13,R12]
movq	mm6,mm1	; MM6 = [w,z]
pfmul	mm5,mm0	; MM5 = [x*R03,x*R02]
movq	mm0,[eax+32]	; MM0 = [R21,R20]
punpckldq	mm1,mm1	; MM1 = [z,z]
pfmul	mm7,mm2	; MM7 = [y*R13,y*R12]
movq	mm2,[eax+40]	; MM2 = [R23,R22]
pfmul	mm0,mm1	; MM0 = [z*R21,z*R20]
pfadd	mm3,mm4	; MM3 = [x*R01+y*R11,x*R00+y*R10]
movq	mm4,[eax+48]	; MM4 = [R31,R30]
pfmul	mm2,mm1	; MM2 = [z*R23,z*R22]
pfadd	mm5,mm7	; MM5 = [x*R03+y*R13],x*R02+y*R12]
movq	mm1,[eax+56]	; MM1 = [R33,R32]
punpckhdq	mm6,mm6	; MM6 = [w,w]
pfadd	mm3,mm0	; MM3 = [x*R01+y*R11+z*R21,x*R00+y*R10+z*R20]
pfmul	mm4,mm6	; MM4 = [w*R31,w*R30]
pfmul	mm1,mm6	; MM1 = [w*R33,w*R32]
pfadd	mm5,mm2	; MM5 = [x*R03+y*R13+z*R23,x*R02+y*R12+z*R22]
pfadd	mm3,mm4	; MM3 = [x*R01+y*R11+z*R21+w*R31,

234 Optimizing with SIMD Instructions Chapter 9