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Proposed change to pp.c (readability)

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November 29, 1999 08:15
Proposed change to pp.c (readability)
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I propose a small change to pp.c strictly for the sake of readability. I noticed
recently that, in the functions pp_pack and pp_unpack, 'pat', which is a
character pointer stored in a register, is reused in a few places for a
completely different purpose: it points not to the pack/unpack pattern but to
the data. I take it that this was done in order to borrow the register, but it
seems bad to me for these reasons: (a) the technique may be confusing; (b) on
most RISC machines, there should be plenty of registers to go around, so you
could just ask for another one; (c) there's no guarantee that pat will be stored
in a register anyhow; and (d) any gain in speed that comes from using a register
is probably tiny and must be weighed against the reduced readability.

I therefore propose that pat be left alone and that a new pointer be defined to
point to the input data in these places. My proposed changes are attached in
diff format. The original file was from version 5.005_03. Your comments are

(See attached file: ppdiff.txt)

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