Ehsan Akhgari wrote:
On 2014-02-26, 4:52 AM, Neil wrote:
The one that I spotted is that MSVC is unable to optimise static
variables, e.g. when you write static const length =
ArrayLength(array); If you write this as a local then the compiler is
able to optimise it away in release builds.
So you mean the problematic cases happen when that variable is at a
global scope or something?
Doesn't have to be at global scope, could be static function scope (in
which case you get a static constructor... at least at global scope it
manages to optimise that away).
Note that I don't think that we need to care about the performance
of ArrayLength() in non-optimized builds.
Debug builds are now sufficiently slow that I no longer dogfood them,
but as it happens MSVC is able to optimise MOZ_ARRAY_LENGTH in both
opt and debug builds.
Wanting faster debug builds is a good thing. I doubt that the subject
of this thread will give you those though. :-)
Well, it was low-hanging fruit.
My suggestions: first, build with --enable-debug --enable-optimize.
That results in an undebuggable build, as the debugger won't be able to
examine most variables, which rather defeats the object of debugging.
On 2014-02-24, 1:25 PM, Chris Peterson wrote:
To avoid developers and reviewers from having to remember special
cases, maybe MOZ_ARRAY_LENGTH should just be the standard everywhere.
They're not quivalent.
Would you mind xpanding on that?
Sure. mozilla::ArrayLength has a special case for mozilla::Array
That's readily fixed.
template <typename T, size_t N>
char (&ArrayLengthHelper(const Array </mozilla-central/ident?i=Array><T
</mozilla-central/ident?i=T>, N </mozilla-central/ident?i=N>>& arr
</mozilla-central/ident?i=arr>ay))[N];
Want me to file a bug?
--
Warning: May contain traces of nuts.
_______________________________________________
dev-platform mailing list
dev-platform@lists.mozilla.org
https://lists.mozilla.org/listinfo/dev-platform
