Subject: [stella] 6502 basics: signed LSR From: KirkIsrael@xxxxxxxxxxxxx Date: 15 Feb 2004 17:41:58 -0000 |
Is there a better way of dividing a signed 1-byte integer by 2 than this? (which says, if var is positive, just do LSR, otherwise LSR and OR w/ -128 i.e. #%10000000 ) It just seems odd to have to branch to preserve the sign bit but I wasn't clever enough to come up with a better way... LDA var BPL posval negval LSR ORA #-128 JMP done posval LSR done STA var -- KirkIsrael@xxxxxxxxxxxxx http://kisrael.com The purpose of conversation isn't to demonstrate one's glib intelligence; it's how we stumble and grope our way through the mists and arrive at something like intelligence. --Mr. Blue ---------------------------------------------------------------------------------------------- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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