Improve fasta scanner performance

Improve fasta scanner performance

Reorder cases in bigSwitch according
to frequency, reduce the number of
comparisons.

R=ahe@google.com

Committed: https://github.com/dart-lang/sdk/commit/8dda473a55e11926c6cb338cace463d7b28fefb0

[Dmitry Olshansky, 2017-02-24 17:14:58]

dmitryolsh@google.com changed reviewers:
+ ahe@google.com

[ahe, 2017-02-25 10:38:32]

lgtm

Thank you, how much improvement do you see?

Initially, I did order them based on frequency, but I guess things have changed
a lot since then.

[Dmitry Olshansky, 2017-03-06 10:34:22]

On 2017/02/25 10:38:32, ahe wrote:
> lgtm
> 
> Thank you, how much improvement do you see?
> 
> Initially, I did order them based on frequency, but I guess things have
changed
> a lot since then.

On the full compiler I can't find the difference in the noise.
Running scanner separately I see 1% improvement, not much but still noticeable.

[Dmitry Olshansky, 2017-03-06 10:34:22]

On 2017/02/25 10:38:32, ahe wrote:
> lgtm
> 
> Thank you, how much improvement do you see?
> 
> Initially, I did order them based on frequency, but I guess things have
changed
> a lot since then.

On the full compiler I can't find the difference in the noise.
Running scanner separately I see 1% improvement, not much but still noticeable.

[Dmitry Olshansky, 2017-03-06 10:35:36]

Description was changed from

==========
Improve fasta scanner performance

Reorder cases in bigSwitch according
to frequency, reduce the number of
comparisons.
==========

to

==========
Improve fasta scanner performance

Reorder cases in bigSwitch according
to frequency, reduce the number of
comparisons.

R=ahe@google.com

Committed:
https://github.com/dart-lang/sdk/commit/8dda473a55e11926c6cb338cace463d7b28fefb0
==========

[Dmitry Olshansky, 2017-03-06 10:35:38]

Committed patchset #1 (id:1) manually as
8dda473a55e11926c6cb338cace463d7b28fefb0 (presubmit successful).