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Index > Windows > Storing data in code segment

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prino



Joined: 24 Jun 2004
Posts: 20
prino
Busy converting old 16-bit code. Uses this construction:

Code:
  mov   cx, offset @1
  call  cs_2_line

  db    $00
  db    " +-----+-----+-----+-----+"
@1:
    


with 'cs_2_line' moving the data following the call to a variable and returning to the '@1' label. I can (obviously) change this to 32-bit, but would it be better (performance-wise) to move the strings to a more appropriate location, i.e. the data segment?

Robert
Post 01 Nov 2008, 18:50
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 17662
Location: In your JS exploiting you and your system
revolution
There may be a small improvement in performance if you match the call and ret into natural pairs (the modern CPUs have special circuitry to make call-ret pairs quite efficient). Also if the data are all grouped into one location you may get a small improvement because of cache locality. Although, these potential performance improvements would be quite minor for most applications so don't expect too much.
Post 01 Nov 2008, 19:09
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vid
Verbosity in development


Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia
vid
On my machine, mismatched call/ret take about 18 cycles, and matched 1-2 cycles, so that is IMO really not worth of special care.
Post 02 Nov 2008, 12:24
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