Post by thread:A couple of macros for you

Hi, Thought I'd share a couple of macros that I have written with you: ; Variable definition: cblock acca:0, acca_h, acca_l ; two two-byte accumulators (ints) accb:0, accb_h, accb_l ; ms byte first endc _negint: macro aaa ; negates an integer comf aaa+1, f incf aaa+1, f btfsc status, z decf aaa, f comf aaa, f endm _addint: macro aaa, bbb ; add two integers together result in bbb movf aaa+1, w addwf bbb+1, f btfsc status, c incf bbb, f movf aaa, w addwf bbb, f endm _setint: macro aaa, lll ; sets integer aaa to literal value lll if low(lll)==0 clrf aaa+1 else movlw low(lll) movwf aaa+1 endif if high(lll)==0 clrf aaa else movlw high(lll) movwf aaa endif endm in use: _setint acca, h'0001' _setint accb, h'0001' _addint acca, accb accb now has the result of the sum: 1+1 Comments invited. Regards, Mike Watson

Mayes uk <spam_OUTmikeTakeThisOuTd-m-g.demon.co.uk> wrote: > _setint: macro aaa, lll ; sets integer aaa to literal value lll > if low(lll)==0 > clrf aaa+1 > else > movlw low(lll) > movwf aaa+1 > endif > > if high(lll)==0 > clrf aaa > else > movlw high(lll) > movwf aaa > endif > endm > > .... > > Comments invited. Mike: It's trivial, I know, but you can rewrite the above macro to allow it to generate code like the following when the high and low bytes of "lll" happen to be equal: MOVLW lll MOVWF aaa+1 MOVWF aaa To do it, the macro should look something like this: _setint: macro aaa,lll ; sets integer aaa to literal value lll if (low (lll) == 0) clrf (aaa) + 1 else movlw low (lll) movwf (aaa) + 1 endif if (high (lll) == 0) clrf aaa else if (high (lll) != low (lll)) movlw high (lll) endif movwf aaa endif endm -Andy === Andrew Warren - .....fastfwdKILLspam@spam@ix.netcom.com === === Fast Forward Engineering - Vista, California === === === === Custodian of the PICLIST Fund -- For more info, see: === === http://www.geocities.com/SiliconValley/2499/fund.html ===

Sorry... I left out a couple of sets of parentheses. It'll hardly ever matter, but just to be safe, here's the correct version: _setint: macro aaa,lll ; sets integer aaa to literal value lll if (low (lll) == 0) clrf (aaa) + 1 else movlw low (lll) movwf (aaa) + 1 endif if (high (lll) == 0) clrf (aaa) else if (high (lll) != low (lll)) movlw high (lll) endif movwf (aaa) endif endm -Andy === Andrew Warren - fastfwdKILLspamix.netcom.com === === Fast Forward Engineering - Vista, California === === === === Custodian of the PICLIST Fund -- For more info, see: === === http://www.geocities.com/SiliconValley/2499/fund.html ===

In message <.....199702102217.OAA11646KILLspam.....dfw-ix1.ix.netcom.com> EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU writes: > Mike: > > It's trivial, I know, but you can rewrite the above macro to allow it > to generate code like the following when the high and low bytes of > "lll" happen to be equal: Andy, Nice one. I never thought of that situation. I'll pinch it if I may. All three macros are trivial, but they are my first(s). I've been having a look at some of the available C compilers and am experimenting to see if some well crafted macros can provide things that some of the c compilers can't - like signed integer math for one. Regards, Mike Watson