Re: Test Decimal Instruction
From: "Bob Raicer" Sent: Wednesday, March 09, 2022 5:04 AM You might want to consider using this (or a similar) code sequence. It eliminates the use of EXECUTE instructions and verifies that the length of the source data is acceptable, i.e., the length is positive and does not exceed the length of the "work area" (field PWORK16). And, of course, it validates the data as being in the Packed Decimal format. : ZAP PWORK16,KP0 Initialize the area to : * receive the Packed Decimal : * item. : * : CLFI R2,L'PWORK16 * Br if the length of the : JHNOTGOOD * source item is greater : * * than the length of the : * * work area. The length of a source item is allowed to be longer than that of the destination, in ZAP. What matters is whether any significant digits are lost during the operation. : * : LNR R15,R2 * Negate the source item : JZNOTGOOD * length and branch if : * * zero. Jump on zero and positive is more robust. : * : LAR14,PWORK16+L'PWORK16(R15) : * Set the MVCL 'To' adrs. : LRR15,R2 Set the MVCL 'To' length. : LRR0,R1Set the MVCL 'From' adrs. : LRR1,R2Set the MVCL 'From' length. : * : MVCL R14,R0 Copy the source item to : * the work area (right aligned). : * : TPPWORK16 * Verify the copy of the : JNZ NOTGOOD * source item is valid : * * Packed Decimal format. : * : * - do something with the validated data. : * : * : NOTGOOD DC0H'0' : MVC MACRO,=CL8'CONVERT' : LR R5,R7 : LHI R15,-7 : B RETERR : * : KP0 DCPL1'0' --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
Re: Test Decimal Instruction
You might want to consider using this (or a similar) code sequence. It eliminates the use of EXECUTE instructions and verifies that the length of the source data is acceptable, i.e., the length is positive and does not exceed the length of the "work area" (field PWORK16). And, of course, it validates the data as being in the Packed Decimal format. [Note: I shifted the code right a couple of columns and put a non-blank in column one to avoid strange text flowing problems with the list server system.] : ZAP PWORK16,KP0 Initialize the area to : * receive the Packed Decimal : * item. : * : CLFI R2,L'PWORK16 * Br if the length of the : JHNOTGOOD * source item is greater : * * than the length of the : * * work area. : * : LNR R15,R2 * Negate the source item : JZNOTGOOD * length and branch if : * * zero. : * : LAR14,PWORK16+L'PWORK16(R15) : * Set the MVCL 'To' adrs. : LRR15,R2 Set the MVCL 'To' length. : LRR0,R1Set the MVCL 'From' adrs. : LRR1,R2Set the MVCL 'From' length. : * : MVCL R14,R0 Copy the source item to : * the work area (right aligned). : * : TPPWORK16 * Verify the copy of the : JNZ NOTGOOD * source item is valid : * * Packed Decimal format. : * : * - do something with the validated data. : * : * : NOTGOOD DC0H'0' : MVC MACRO,=CL8'CONVERT' : LR R5,R7 : LHI R15,-7 : B RETERR : * : KP0 DCPL1'0'
Re: Test Decimal Instruction
"IBM Mainframe Assembler List" wrote on 03/07/2022 06:44:52 PM: > The code is not robust. You need to test for R2 being negative > after you subtract 1 from it. A greater than zero test is performed previous to the instructions shown. > Why AHI R2,-(1) and not AHI R1,-1 ? It actually comes from an SHI macro I created. > TP requires the length in a different place from ZAP. > You need to shift R2 left by 4 places, before executing TP. > Then, you need to shift R2 right by 4 places, before executing ZAP. Yes, that is what my second post said. Thanks. > Why do you need the TP instruction? > ZAP tests the second operand for valid sign and valid digits. Because ZAP produces a program exception where TP does not. Sincerely, Dave Clark -- int.ext: 91078 direct: (937) 531-6378 home: (937) 751-3300 Winsupply Group Services 3110 Kettering Boulevard Dayton, Ohio 45439 USA (937) 294-5331 * This email message and any attachments is for use only by the named addressee(s) and may contain confidential, privileged and/or proprietary information. If you have received this message in error, please immediately notify the sender and delete and destroy the message and all copies. All unauthorized direct or indirect use or disclosure of this message is strictly prohibited. No right to confidentiality or privilege is waived or lost by any error in transmission. *
Re: Test Decimal Instruction
> Why AHI R2,-(1) and not AHI R1,-1 ? Looks like macro generated code to me, and -(1) is perfectly valid. > ZAP tests the second operand for valid sign and valid digits But returns the result of the test in a more dramatic fashion than TP. Charles -Original Message- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Robin Vowels Sent: Monday, March 7, 2022 3:45 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Test Decimal Instruction On 2022-03-08 09:16, Dave Clark wrote: > I'm confused... I don't understand why the TEST DECIMAL > instruction is rejecting the following situation. Instead of dropping > down to the second execute instruction, it is falling into the error > reporting logic. Why is that? > > > R1 => x'0108010C' > R2 == 4 > > AHI R2,-(1) > IF0027 DS0H > EXR2,TEST_IT > BZELSE0027 > THEN0027 DS0H >MVC MACRO,=CL8'CONVERT' >LR R5,R7 >LHI R15,-7 >B RETERR > TEST_IT TP0(0,R1) > ZAP_IT ZAP PWORK16,0(0,R1) > ELSE0027 DS0H > ENDF0027 DS0H > EXR2,ZAP_IT And PWORK16? Better to include the assembler listing for the segment, including PWORK16. The code is not robust. You need to test for R2 being negative after you subtract 1 from it. Why AHI R2,-(1) and not AHI R1,-1 ? TP requires the length in a different place from ZAP. You need to shift R2 left by 4 places, before executing TP. Then, you need to shift R2 right by 4 places, before executing ZAP. Why do you need the TP instruction? ZAP tests the second operand for valid sign and valid digits.
Re: Test Decimal Instruction
On 2022-03-08 09:16, Dave Clark wrote: I'm confused... I don't understand why the TEST DECIMAL instruction is rejecting the following situation. Instead of dropping down to the second execute instruction, it is falling into the error reporting logic. Why is that? R1 => x'0108010C' R2 == 4 AHI R2,-(1) IF0027 DS0H EXR2,TEST_IT BZELSE0027 THEN0027 DS0H MVC MACRO,=CL8'CONVERT' LR R5,R7 LHI R15,-7 B RETERR TEST_IT TP0(0,R1) ZAP_IT ZAP PWORK16,0(0,R1) ELSE0027 DS0H ENDF0027 DS0H EXR2,ZAP_IT And PWORK16? Better to include the assembler listing for the segment, including PWORK16. The code is not robust. You need to test for R2 being negative after you subtract 1 from it. Why AHI R2,-(1) and not AHI R1,-1 ? TP requires the length in a different place from ZAP. You need to shift R2 left by 4 places, before executing TP. Then, you need to shift R2 right by 4 places, before executing ZAP. Why do you need the TP instruction? ZAP tests the second operand for valid sign and valid digits.
Re: Test Decimal Instruction
Don't forget to reset R2 for the ZAP! Charles -Original Message- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Dave Clark Sent: Monday, March 7, 2022 2:25 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Test Decimal Instruction "IBM Mainframe Assembler List" wrote on 03/07/2022 05:16:50 PM: > I'm confused... I don't understand why the TEST DECIMAL > instruction is rejecting the following situation. Instead of dropping > down to the second execute instruction, it is falling into the error > reporting logic. Why is that? > > > R1 => x'0108010C' > R2 == 4 > > AHI R2,-(1) > IF0027 DS0H > EXR2,TEST_IT > BZELSE0027 > THEN0027 DS0H >MVC MACRO,=CL8'CONVERT' >LR R5,R7 >LHI R15,-7 >B RETERR > TEST_IT TP0(0,R1) > ZAP_IT ZAP PWORK16,0(0,R1) > ELSE0027 DS0H > ENDF0027 DS0H > EXR2,ZAP_IT Ah, I think I know why. It is because I am executing the TP instruction and the length of the first operand is supposed to be in bits 8 to 11 instead of bits 12 to 15 where my length from R2 would end up. Sincerely, Dave Clark -- int.ext: 91078 direct: (937) 531-6378 home: (937) 751-3300 Winsupply Group Services 3110 Kettering Boulevard Dayton, Ohio 45439 USA (937) 294-5331 * This email message and any attachments is for use only by the named addressee(s) and may contain confidential, privileged and/or proprietary information. If you have received this message in error, please immediately notify the sender and delete and destroy the message and all copies. All unauthorized direct or indirect use or disclosure of this message is strictly prohibited. No right to confidentiality or privilege is waived or lost by any error in transmission. *
Re: Test Decimal Instruction
L1 appears to be in the bits 8-11 nibble. Try an SLL 4 on R2. Charles -Original Message- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Dave Clark Sent: Monday, March 7, 2022 2:17 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Test Decimal Instruction I'm confused... I don't understand why the TEST DECIMAL instruction is rejecting the following situation. Instead of dropping down to the second execute instruction, it is falling into the error reporting logic. Why is that? R1 => x'0108010C' R2 == 4 AHI R2,-(1) IF0027 DS0H EXR2,TEST_IT BZELSE0027 THEN0027 DS0H MVC MACRO,=CL8'CONVERT' LR R5,R7 LHI R15,-7 B RETERR TEST_IT TP0(0,R1) ZAP_IT ZAP PWORK16,0(0,R1) ELSE0027 DS0H ENDF0027 DS0H EXR2,ZAP_IT Sincerely, Dave Clark -- int.ext: 91078 direct: (937) 531-6378 home: (937) 751-3300 Winsupply Group Services 3110 Kettering Boulevard Dayton, Ohio 45439 USA (937) 294-5331 * This email message and any attachments is for use only by the named addressee(s) and may contain confidential, privileged and/or proprietary information. If you have received this message in error, please immediately notify the sender and delete and destroy the message and all copies. All unauthorized direct or indirect use or disclosure of this message is strictly prohibited. No right to confidentiality or privilege is waived or lost by any error in transmission. *
Re: Test Decimal Instruction
"IBM Mainframe Assembler List" wrote on 03/07/2022 05:16:50 PM: > I'm confused... I don't understand why the TEST DECIMAL > instruction is rejecting the following situation. Instead of dropping > down to the second execute instruction, it is falling into the error > reporting logic. Why is that? > > > R1 => x'0108010C' > R2 == 4 > > AHI R2,-(1) > IF0027 DS0H > EXR2,TEST_IT > BZELSE0027 > THEN0027 DS0H >MVC MACRO,=CL8'CONVERT' >LR R5,R7 >LHI R15,-7 >B RETERR > TEST_IT TP0(0,R1) > ZAP_IT ZAP PWORK16,0(0,R1) > ELSE0027 DS0H > ENDF0027 DS0H > EXR2,ZAP_IT Ah, I think I know why. It is because I am executing the TP instruction and the length of the first operand is supposed to be in bits 8 to 11 instead of bits 12 to 15 where my length from R2 would end up. Sincerely, Dave Clark -- int.ext: 91078 direct: (937) 531-6378 home: (937) 751-3300 Winsupply Group Services 3110 Kettering Boulevard Dayton, Ohio 45439 USA (937) 294-5331 * This email message and any attachments is for use only by the named addressee(s) and may contain confidential, privileged and/or proprietary information. If you have received this message in error, please immediately notify the sender and delete and destroy the message and all copies. All unauthorized direct or indirect use or disclosure of this message is strictly prohibited. No right to confidentiality or privilege is waived or lost by any error in transmission. *
Test Decimal Instruction
I'm confused... I don't understand why the TEST DECIMAL instruction is rejecting the following situation. Instead of dropping down to the second execute instruction, it is falling into the error reporting logic. Why is that? R1 => x'0108010C' R2 == 4 AHI R2,-(1) IF0027 DS0H EXR2,TEST_IT BZELSE0027 THEN0027 DS0H MVC MACRO,=CL8'CONVERT' LR R5,R7 LHI R15,-7 B RETERR TEST_IT TP0(0,R1) ZAP_IT ZAP PWORK16,0(0,R1) ELSE0027 DS0H ENDF0027 DS0H EXR2,ZAP_IT Sincerely, Dave Clark -- int.ext: 91078 direct: (937) 531-6378 home: (937) 751-3300 Winsupply Group Services 3110 Kettering Boulevard Dayton, Ohio 45439 USA (937) 294-5331 * This email message and any attachments is for use only by the named addressee(s) and may contain confidential, privileged and/or proprietary information. If you have received this message in error, please immediately notify the sender and delete and destroy the message and all copies. All unauthorized direct or indirect use or disclosure of this message is strictly prohibited. No right to confidentiality or privilege is waived or lost by any error in transmission. *
