On Thu, 8 Oct 2015 10:29:47 -0600, Paul Gilmartin wrote: >So, should every implied register reference be documented in situ, perhaps >by a line comment?
I say "no". David's document recommended doing just that, using a 0-length Y-con, but I think his point was to get the reference included in the cross-reference. Presumably, this is a practice that he began using before the assembler included the implicit references in a cross-reference. Apparently it was a point that Brent completely missed. The value of the cross-reference is not in understanding a particular line of code, but for finding where a register is used, and where it is changed. If I have a section of code where I want to use an additional register, I can look at every instruction in that section to see which registers are used, or I can use the cross-reference. >Can any implied register reference be regarded as >"common knowledge"? An assembler programmer should know the effects of the instructions that he uses. >What about Multiply which makes an implied reference >to the odd register adjacent to its explicit target? (I assume the admirable >cross-reference list reports that.) Yes, the cross-reference reports that use by multiply, as well as every register referenced by STM and altered by LM and their siblings. -- Tom Marchant
