Hi Gunnar, I like your solution, but you have changed the lengths in the original table. I don't know if the OP (Mark) haa that option.
Peter On Thu, 6 Jun 2024 at 10:31, <g...@altiboxmail.no> wrote: > Hi > > I think the BXLE instruction is not used correct in the proposed > solution. From the manual's description: > > BXLE R1,R3,D2(B2) > "When the R3 field is even, it designates a pair of registers; > the contents of the even and odd registers of > the pair are used as the increment and the compare > value, respectively. When the R3 field is odd, it designates > a single register, the contents of which are > used as both the increment and the compare value." > > Using the syntax of BXLE described above: > The 1st operand, R1, should point to the current entry in the table. > The second operand, D2(B2), should point to the beginning of the loop. > The 3rd operand, R3, should be an even register, and contain the increment. > The odd register, R3+1, should point before the end of the table, but not > before the last entry in the table. > > The program will be simplest when the length fields are considered part of > the entry. > Using registers 7,8,9, where 7 points to the current entry, 8 has the > increment, and 9 has the compare value. > > LA 7,ENT1 point to 1st entry > LA 9,END-1 point to 1 before the > end of table (since the loop instruction is BXLE and not BXL) > LOOP CLC 2(9,7),=C'FFFFFFFFF' test for a specific entry > BE FOUND leave loop if found > LH 8,0(7) length of current > entry > BXLE 7,8,LOOP increment entry pointer to > next entry > B NOTFOUND the specific entry was not > found > > ENT1 DC AL2(ENT2-ENT1),CL14'AAAAAAAAAAAAAA' length of 1st entry, > and value of 1st entry > ENT2 DC AL2(ENT3-ENT2),CL15'BBBBBBBBBBBBBBB' length of 2nd entry, > and value of 2nd entry > ENT3 DC AL2(ENT4-ENT3),CL17'CCCCCCCCCCCCCCCCC' > ENT4 DC AL2(ENT5-ENT4),CL13'DDDDDDDDDDDDD' > ENT5 DC AL2(ENT6-ENT5),CL23'EEEEEEEEEEEEEEEEEEEEEEE' > ENT6 DC AL2(ENT7-ENT6),CL9'FFFFFFFFF' > ENT7 DC AL2(ENT8-ENT7),CL19'GGGGGGGGGGGGGGGGGGG' > ENT8 DC AL2(ENT9-ENT8),CL25'HHHHHHHHHHHHHHHHHHHHHHHHH' > ENT9 DC AL2(END-ENT9),CL8'IIIIIIII' > END EQU * > > There is still a bug here, since the CLC may test beyond the end of the > table (if the entry tested for is not found). > The entry length should be checked first, and if not equal then branch to > the LH instruction. > > Gunnar > > > > > > > -----Original Message----- > From: IBM Mainframe Assembler List <ASSEMBLER-LIST@LISTSERV.UGA.EDU> On > Behalf Of Mark Young > Sent: Wednesday, June 5, 2024 6:08 PM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: BXLE usage assistance > > Thanks Peter, > > I tested the program with your suggested updates and it worked. I tried > all the entries in the table and it worked for all of them. > Thanks again for your help. Very much appreciated. > > Thanks, > Mark. > . > > On Wed, Jun 5, 2024 at 3:42 AM Peter Vels <peter.v...@gmail.com> wrote: > > > Hi Mark, > > > > Try this: > > > > <snip> > > CHKOPTS1 LA R7,TABLE1+4 ADDRESS OF FIRST ELEMENT > > LH R8,TABLE1+2 LENGTH OF TABLE ENTRY > > LR R6,R8 SAVE R8 FOR LATER > > LA R9,TABLE1+2 ADDRESS OF BEGINNING OF TABLE > > AH R9,TABLE1 CALC ADDR OF END OF TABLE > > > > LOOP1 CLC 0(9,R7),=C'FFFFFFFFF' > > JE FOUND ENTRY FOUND = RC=0 > > * --->>> LH R8,0(2,R7) <<<--- POINT TO LENGTH OF NEXT ENTRY > > LR R8,R6 RESTORE R8 > > LH R6,0(R8,R7) PUT THE NEXT LENGTH INTO R6 > > LA R7,2(R7) SKIP OVER THE LENGTH FIELD > > BXLE R7,R8,LOOP1 LOOPING UNTIL OPT FOUND > > <snip> > > > > I don't like that I used an extra register, R6, so I'm hoping someone > > can improve it. > > > > Peter > > > > On Wed, 5 Jun 2024 at 03:58, Mike Shaw <quick...@gmail.com> wrote: > > > > > Mark, > > > > > > You are coding a length (the 2) in the 2nd operand of your LH > > > instruction...that 2 is being used by the machine as register 2. LH > > always > > > loads two bytes. > > > > > > Mike Shaw > > > MVS/QuickRef Support > > > Chisoft > > > > > > > > > On Tue, Jun 4, 2024, 1:38 PM Mark Young <ca45...@gmail.com> wrote: > > > > > > > Thanks for all the replies. See the code sample below. I'm > > > > getting > > > stuck > > > > trying to get the length for the next table entry into R8 so the > > > > BXLE instruction loop the correct length. Let me know if I'm on the > correct > > > > path, or I'm in never never land. Also, the --->>> <<<--- > is > > > > where I think I'm getting stuck. > > > > > > > > TESTBXLE CSECT , > > > > TESTBXLE AMODE 31 > > > > TESTBXLE RMODE ANY > > > > SAVE (14,12),,TESTBXLE*&SYSDATE*&SYSTIME > > > > BALR R12,0 R12 - BASE REGISTER > > > > USING *,R12 ESTABLISH ADDRESSABILITY > > > > ST R13,SAVEAREA+4 SAVEAREA > > > > LA R13,SAVEAREA POINTERS > > > > * > > > > CHKOPTS1 LA R7,TABLE1+4 ADDRESS OF FIRST ELEMENT > > > > LH R8,TABLE1+2 LENGTH OF TABLE ENTRY > > > > LA R9,TABLE1+2 ADDRESS OF BEGINNING OF TABLE > > > > AH R9,TABLE1 CALC ADDR OF END OF TABLE > > > > LOOP1 CLC 0(9,R7),=C'FFFFFFFFF' > > > > BE FOUND ENTRY FOUND = RC=0 > > > > --->>> LH R8,0(2,R7) <<<--- POINT TO LENGTH OF NEXT ENTRY > > > > BXLE R7,R8,LOOP1 LOOPING UNTIL OPT FOUND > > > > B NOTFND ENRTY NOT FOUND ? RC=8 > > > > * > > > > FOUND L R13,SAVEAREA+4 > > > > RETURN (14,12),RC=0 > > > > * > > > > NOTFND L R13,SAVEAREA+4 > > > > RETURN (14,12),RC=8 > > > > * > > > > PRINT NOGEN > > > > YREGS > > > > SAVEAREA DS 18F > > > > TABLE1 DS 0F > > > > DC XL2'008F' > > > > DC XL2'000E',CL14'AAAAAAAAAAAAAA' > > > > DC XL2'000F',CL15'BBBBBBBBBBBBBBB' > > > > DC XL2'0011',CL17'CCCCCCCCCCCCCCCCC' > > > > DC XL2'000D',CL13'DDDDDDDDDDDDD' > > > > DC XL2'0017',CL23'EEEEEEEEEEEEEEEEEEEEEEE' > > > > DC XL2'0009',CL9'FFFFFFFFF' > > > > DC XL2'0013',CL19'GGGGGGGGGGGGGGGGGGG' > > > > DC XL2'0019',CL25'HHHHHHHHHHHHHHHHHHHHHHHHH' > > > > DC XL2'0008',CL8'IIIIIIII' > > > > END TESTBXLE > > > > > > > > > > > > Thanks, > > > > Mark. > > > > > > > > > >
