Please note: We are aware of an issue affecting replies on the Arm Community forums, which may not be loading as expected.
We apologize for any inconvenience and appreciate your patience while we investigate and work to resolve the issue.
Thank you for your understanding.
Can anyone explain what this code is doing
LDMIA r0,{r5-r9} ; get the next 5 data values to be filtered ADD r5,r5,r9 ; sum x[-2] with x[2] ADD r6,r6,r8 ; sum x[-1] with x[1] ADD r9,r5,r6 ; sum x[-2]+x[2] with x[-1]+x[1] ADD r7,r7,r9,LSR #1 ; sum x[0] with (x[-2]+x[2]+x[-1]+x[1])/2 MOV r7,r7,LSR #2 ; form (x[0] + (x[-2]+x[-1]+x[1]+x[2])/2)/4 STR r7,[r3],#4 ; save calculated filtered value, move to next output data item ADD r0,r0,#4 ; move to start of next 5 input data values SUBS r4,r4,#1 ; move on to next set of 5 inputs BPL filter_loop ; continue until last set of 5 inputs reached