stmdb	sp!, {r4, r5, r6, r7, r8, r9, r10, r11}	
	ldmia	r0, {r1, r2, r3, r4, r5, r6, r7, r8}	
	sub	r9, r1, r3	;t3 = z[0].re - z[1].re;
	add	r10, r3, r1	;t1 = z[0].re + z[1].re;
				;r1, r3 now free
	

				
	sub	r1, r6, r8	;t7 = z[2].im - z[3].im;
	add	r3, r6, r8	;t5 = z[2].im + z[3].im;
				;r6, r8 now free
				
	sub	r11, r7, r5	;t8 = z[3].re - z[2].re;		
	add	r12, r7, r5	;t6 = z[3].re + z[2].re;
				;r7, r5 now free
				
				
	sub	r5, r2, r4	;t4 = z[0].im - z[1].im
	add	r7, r2, r4	;t2 = z[0].im + z[1].im;
				;r2, r4 now free				
	
	;have r2,r4,r6,r8 free
	
	sub r8, r5, r11		;r8 = t4 - t8;
	sub r6, r7, r3		;r6 = t2 - t5;
	add r4, r5, r11		;r4 = t4 + t8;
	add r2, r7, r3		;r2 = t2 + t5;
	;have r3, r7, r5, r11 free

	sub r5, r10, r12	;r5 = t1 - t6;
	sub r7, r9, r1		;r7 = t3 - t7;	
	add r3, r9, r1		;r3 = t3 + t7;				
	add r1, r10, r12	;r1 = t1 + t6;
	
	stmia	r0, {r1, r2, r3, r4, r5, r6, r7, r8}
	ldmia	sp!, {r4, r5, r6, r7, r8, r9, r10, r11}