Re: [ql-users] Assembly question

[P Witte]

Jerome Grimbert writes: > My assembly being a little rusted, I would like to check with the knowledgeable > people the following portion of code. > > >               ... >               tst.l   d2 >               beq.s   first_place > second_place: >               ... > > Now, if d2 is 0, would executing that code reach first_place or second_place ? > (I have my idea, but I do not want to influence the audience). > > Thanks for your attention.   Glad to see that "assembly questions" still appear to attract a lot of interest. I too sometimes have problems with conditionals. Probably something to do with latent dyslexia (I really must get round to joining the DNA - National Dyslexia Association  ;) (If you dont get the joke you are probably a sufferer too!) My solution was to create and use the following table:                              Conditional branching (bcc)                            ---------------------------                                    CMP Dx,Dy                           X = branch taken, N Z C = flags set               Dx/Dy  |  1/0  |  1/1  | -1/0  |  0/1  | 1/-1  | -2/-1 |             Flags  |   NC  |   Z   |   C   | ----  |   N   |  ---- |                    + - - - + - - - + - - - + - - - + - - - + - - - +           U   bhi  |       |       |       |   X   |   X   |   X   |                    +       +       +       +       +       +       +           U   bls  |   X   |   X   |   X   |       |       |       |                    +       +       +       +       +       +       +           U   bcc  |       |   X   |       |   X   |   X   |   X   |                    +       +       +       +       +       +       +           U   bcs  |   X   |       |   X   |       |       |       |                    +       +       +       +       +       +       +               bne  |   X   |       |   X   |   X   |   X   |   X   |                    +       +       +       +       +       +       +               beq  |       |   X   |       |       |       |       |                    +       +       +       +       +       +       +           S   bpl  |       |   X   |   X   |   X   |       |   X   |                    +       +       +       +       +       +       +           S   bmi  |   X   |       |       |       |   X   |       |                    +       +       +       +       +       +       +           S   bge  |       |   X   |   X   |   X   |       |   X   |                    +       +       +       +       +       +       +           S   blt  |   X   |       |       |       |   X   |       |                    +       +       +       +       +       +       +           S   bgt  |       |       |   X   |   X   |       |   X   |                    +       +       +       +       +       +       +           S   ble  |   X   |   X   |       |       |   X   |       |                    +       +       +       +       +       +       +                                       (Please let me know if you discover any mistakes!)                                                                   Per