Okay, this is absolutely my last cut at this. (I've got other things to
do ;-) .) The thing that bothered me in the last iteration was the STC
inside the loop -- too many storage references. Here's a solution that
is very similar to Bob Rutledge's that I like much better because it
performs a total of only two storage references (the ICM and the final
STM):
LHI R0,X'F0'
LHI R1,8
SLR R2,R2
ICM R3,8,BYTE
LOOP SLDL R4,8
SLDL R2,1
OR R5,R2
OR R5,R0
BCT R1,LOOP
STM R4,R5,RESULT
*
BYTE DC B'01110101' Sample input
DS 0D
RESULT DS CL8 Output
34 Instructions
0 Literals
1 Input Area
8 Output Area
43 Total Bytes
10 Total Instructions
At 09:21 PM 12/12/2007, I wrote:
>I didn't originally think of doing the AND and OR inside the loop,
>but based on the reduction in storage references, I think this
>might be even faster, albeit more instructions:
>
> LHI R1,8
> LHI R4,X'F0'
> IC R2,BYTE
>LOOP LHI R3,X'01'
> NR R3,R2
> OR R3,R4
> STC R3,RESULT-1(R1)
> SRL R2,1
> BCT R1,LOOP
>*
>BYTE DC B'01110101' Sample input
>RESULT DS CL8 Output
>
> 32 Instructions
> 0 Literals
> 1 Input Area
> 8 Output Area
>
> 41 Total Bytes
> 9 Total Instructions
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO
Search the archives at http://bama.ua.edu/archives/ibm-main.html
