[webkit-dev] Proposal for serializing alpha channel values; request for algorithm help

[Alfonso Guerra]

On Wed, Nov 4, 2015 at 1:22 PM, Filip Pizlo <fpizlo at apple.com> wrote:

>
> On Nov 4, 2015, at 10:03 AM, Alfonso Guerra <huperniketes at gmail.com>
> wrote:
>
> was ~20% faster on my machine.
>
>
> It’s very surprising that this made any difference.  Compilers are
> ordinarily smart enough to understand the equivalence of ++x and x++ if the
> result is unused.  Are you sure you compiled with optimizations enabled?
>

I hadn't. With full optimizations and tweaking of the driver to prevent the
compiler from optimizing away invocation of the functions entirely, the
difference is only ~1.3-3.3%.

No longer as substantial. It beats Lightspeed C, but it's best not to
depend on optimization for code which is modeled on an obsolete processor
architecture, and is so easy to write. Doubly so when using non-optimized
builds for development.


Alfonso
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