Re: [Ql-Users] Debugging nightmare
- Original Message - From: John Alexander acontractor...@yahoo.co.uk To: ql-us...@q-v-d.com Sent: Wednesday, May 23, 2012 7:07 PM Subject: Re: [Ql-Users] Debugging nightmare Ian, I'm sure it's been doing this for the last 34 years or so ;) Encouraged me to rough up a 68K controller for old school kicks though ..Cheers John A I'm sure it has too, it would be most annoying if it just decided to spontaneously change ... ;o) Trouble is I'd written the program on i386 then converted it to 68k; plus, it had been working for a while, then I broke it, but I'd convinced myself I hadn't made any changes to that bit of code. I must've changed it, then changed it back, and in the process switched the two instructions. Anyway, the good news is it's working now (on both CPUs). cheers, Ian. ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
[Ql-Users] Debugging nightmare
Damn damn damn ... I've just spent nearly a day and a half trying to debug a simple bit of assembler code because I forgot that on m68k CPUs the MOVE instructions alter the flags and I was convinced all sorts of other problems might've been the cause, but in the end all I had to do was swap two instructions: move.l d5,d0 and.l d6,d0- moveq #'0',d1 - beq.s sk1 moveq #'1',d1 sk1 ... should've been: move.l d5,d0 moveq #'0',d1 - and.l d6,d0- beq.s sk1 moveq #'1',d1 sk1 ... That'll teach me not to try to develop the same program on two different platforms at the same time! Damn damn fume blast ... Never mind though, might be a little something for QL Today when I've tidied it all up. Ian. ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Debugging nightmare
Hi Ian, On 23/05/12 12:52, Ian Pine wrote: Damn damn damn ... ... because I forgot that on m68k CPUs the MOVE instructions alter the flags ... Well, it does alter the flags, unless: * You specifically use the MOVEA instruction; or * You specify MOVE with an address register as the destination AND your assembler quietly converts the MOVE to MOVEA. Just to make things interesting. Cheers, Norm. -- Norman Dunbar Dunbar IT Consultants Ltd Registered address: Thorpe House 61 Richardshaw Lane Pudsey West Yorkshire United Kingdom LS28 7EL Company Number: 05132767 ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Debugging nightmare
On 23 May 2012, at 13:24, Norman Dunbar wrote: On 23/05/12 12:52, Ian Pine wrote: Damn damn damn ... ... because I forgot that on m68k CPUs the MOVE instructions alter the flags ... Well, it does alter the flags, unless: * You specifically use the MOVEA instruction; or * You specify MOVE with an address register as the destination AND your assembler quietly converts the MOVE to MOVEA. Just to make things interesting. Just for fun. MOVE USP,An, MOVE An.USP MOVE SR,ea and MOVEC Rc,Rn also leave the condition codes alone. George ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Debugging nightmare
Ian, I'm sure it's been doing this for the last 34 years or so ;) Encouraged me to rough up a 68K controller for old school kicks though ..Cheers John A --- On Wed, 23/5/12, Ian Pine ilp...@tesco.net wrote: From: Ian Pine ilp...@tesco.net Subject: [Ql-Users] Debugging nightmare To: ql-us...@q-v-d.com ql-us...@q-v-d.com Date: Wednesday, 23 May, 2012, 12:52 Damn damn damn ... I've just spent nearly a day and a half trying to debug a simple bit of assembler code because I forgot that on m68k CPUs the MOVE instructions alter the flags and I was convinced all sorts of other problems might've been the cause, but in the end all I had to do was swap two instructions: move.l d5,d0 and.l d6,d0 - moveq #'0',d1 - beq.s sk1 moveq #'1',d1 sk1 ... should've been: move.l d5,d0 moveq #'0',d1 - and.l d6,d0 - beq.s sk1 moveq #'1',d1 sk1 ... That'll teach me not to try to develop the same program on two different platforms at the same time! Damn damn fume blast ... Never mind though, might be a little something for QL Today when I've tidied it all up. Ian. ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
