[fpc-devel] Inc() and Dec() on properties

Mark Morgan Lloyd markMLl.fpc-devel at telemetry.co.uk
Fri Dec 20 22:02:21 CET 2013


A question if I may, leading on from 
http://bugs.freepascal.org/view.php?id=25440

 > - inc(x)/dec(x) with range checking enabled are "optimized" with
 > taking address of x.

Is that why Inc() and Dec() can't be applied to properties, or are there 
other issues?

 > They were using untyped address, causing loss of alignment and
 > generating large and slow code with unaligned access. This is fixed in
 > r26256 and improves all alignment-sensitive targets.

Some platforms, for example ARM/Linux and Solaris/SPARC, fix alignment 
traps in the kernel so programmers might be unaware of any problems. 
Unfortunately, they might also be unaware that this introduces a 
substantial performance hit.

Incidentally, I notice that somebody in Russia is still developing SPARC 
systems http://lists.debian.org/debian-sparc/2013/12/msg00006.html 
http://en.wikipedia.org/wiki/MCST-R1000 I wonder whether they're aware 
that the architecture is well-supported by FPC and Lazarus?

-- 
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]



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