Re: [avr-libc-dev] GCC optimization [Was: avr-libc 1.0.5 released]

[Joerg Wunsch]

[I've broken that out into a separate subject.]

As Paul Schlie wrote:

> Also a minor update, I experimented with disabling gcc's default
> promotion of small integers (char/short) to int; and so far so good,
> now attempting to also limit promoting enum's and bool's to the
> smallest integer type with sufficient precision, as opposed to
> defaulting to int, which 99% of the time will be a char, as most
> enums tend to be small; but will likely miss some places for similar
> improvements, as GCC's expression manipulation code is a bit
> tangled.

Sounds interesting.  If that really works, I think it will obviate the
need for a -mint8 option.

> But unfortunately don't have a great degree of confidence that it
> would be easily accepted, as all targets would need to be tested,
> and although I don't think it would be detrimental to other targets,
> it may effect some of their optimization assumptions if biased
> toward assuming int types, but not sure.

Then it probably needs regression testing.  While not a serious test,
I can offer you to test a patched GCC for building FreeBSD releases,
on at least IA32 and sparc64 hardware (maybe AMD64, too).  I think if
the patched compiler can still compile an entire FreeBSD (kernel and
userland), and the resulting OS is runnable, this would be a good
justification the patch doesn't break GCC's traditional environments.

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)