[LLVMdev] Optimization for size

Don Quixote de la Mancha quixote at dulcineatech.com
Thu Oct 20 00:15:14 PDT 2011

>> Optimization for size hasn't been tested properly, at least not for
>> ARM, and I hit all sorts of trouble (even before getting to DAG) when
>> enabling it.
> Bugzilla or it didn't happen.

Optimization for size on ARM is more important than most other
platforms.  It is still very common for embedded ARM cores to have
only 64 kb of Flash.

A couple friends of mine were two of Atari's first seven video game
coders.  They had a choice of using 2 kb or 1 kb ROMs to store their
executables in.  While 2 kb ROMs allowed for much easier to write and
more featureful games, they always strove to target the 1 kb ROMs
because they cost half as much to manufacture and so the coders would
earn twice as much in royalties.

It happened all the time that a game's executable size would get down
to just a few bytes over 1 kb.  Despite their best efforts, the coders
could never get their executable to 1 kb or less, because doing so
would break the hard-coded timing loops.  I understand that some
coders would go insane as a result.

Don Quixote de la Mancha
Dulcinea Technologies Corporation
Software of Elegance and Beauty
quixote at dulcineatech.com

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