If asterisks will only appear in the first position of a field, you could use a TRT instruction to determine if (and where) an asterisk appears. If one does appear, the position would let you "calculate" which field it appears in so you can move the corresponding data into the compare operand. If more than one field of a table entry can contain an asterisk, you would need to repeat the test until no asterisks remained.
If your outer loop is over the table elements and your inner loop is over the structure data, then I would set a flag for each field of the table containing an asterisk. Then you need only test the flags to determine which structure data needs to be copied to the compare operand. But if you have to do I/O for the structure data, you may want the opposite loop order so you would read each structure element only once. If the number of entries in the Acceptable Values table is reasonable, you could preprocess them into an array of flags and avoid multiple I/Os for that data also. > -----Original Message----- > From: IBM Mainframe Assembler List [mailto:ASSEMBLER- > l...@listserv.uga.edu] On Behalf Of esst...@juno.com > Sent: Saturday, June 17, 2017 8:55 AM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Table Searchig with a Mask > > Hi everyone > > I would like some help in reducing the number of instructions required to search a table. > The table is in no particular order, so a Binary Search may not be appropriate here. > . > . > I will try to explain this. > . > I have a structure with X number of fields > For this example lets assume: > STRUCTURE EQU * > USERID DS CL8 > COMPANY_CODE DS CL4 > JOB_NAME DS CL8 > FILE DS CL8 > > I also have an Array (table) of Acceptable Values with the same elements > as my structure. > I can search the table using a single compare for a length of 28. > . > . > However some of the table entries contain an asterisk "*" in the first position of > the respective field. The asterisk means to accept any value from the structure. > For Example: > ARRAY EQU * > TUSERID DC CL8'JOSEPH ' > TCOMPANY_CODE DC CL4'* ' > TJOB_NAME DC CL8'REPORT ' > TFILE DC CL8'* ' > . > In order to search the table using a single compare instruction, I would need to overlay > the respective elements in the structure with the Asterisk from the corresponding element > in the Array Table Entry. > . > This would mean I would need to compare each element in the ARRAY entry for the > Asterisk, > and if present move the corresponding field to the structure. > CLI TCOMPANY_CODE,=C'*' > JNE NEXT_ELEMENT > MVC COMPANY_CODE,TCOMPANY_CODE > . > I prefer not to test each element in the ARRAY for an Asterisk and Move them individually > to the structure, prior to comparing the structure with the Array Entry. > . > I'm not aware of any instruction that will move selectively all fields > with an Asterisk "*". Which Is what I am looking for, then I can use a single move > or four Moves and continue to use a single compare instruction. > . > Again I'm looking for the fewest amount of instructions to accomplish this. > . > What Alternatives are there ? > A long time ago I did see someone do something similar with a Translate and Test. > But again this is several iterations of TRT and a Move for each Array element. > . > > Thank You > Paul D'Angelo > ************
