Another round of GVN is sometimes worthwhile after code motion

Another round of GVN is sometimes worthwhile after code motion

Code motion really should be integrated with of GVN, since GVN and
code motion generate opportunities for each other.  Looking at a
sample of functions it is rare that the extra phases execute solely
due to code motion, so I don't think this much of a compile-time risk
and benchmarks back that up.

This fixes some sad looking code from a pending CL.

R=sigmund@google.com

Committed: https://github.com/dart-lang/sdk/commit/65efe1dc082abbf2b070403519f62311b0ee457b

[sra1, 2016-09-07 02:49:53]

Description was changed from

==========
Another round of GVN is sometimes worthwhile after code motion

Code motion really should be integrated with of GVN, since GVN and
code motion generate opportunities for each other.  Looking at a
sample of functions it is rare that the extra phases execute, so I
don't think this is causing the compiler to be unnecessarily slower.

This fixes some sad looking code from a pending CL.

Also fix a bug where conditional constant interceptors could be pessimised.



BUG=
==========

to

==========
Another round of GVN is sometimes worthwhile after code motion

Code motion really should be integrated with of GVN, since GVN and
code motion generate opportunities for each other.  Looking at a
sample of functions it is rare that the extra phases execute solely
due to code motion, so I don't think this much of a compile-time risk.

This fixes some sad looking code from a pending CL.

Also fix a bug where conditional constant interceptors could be pessimised.



BUG=
==========

[sra1, 2016-09-07 02:49:54]

sra@google.com changed reviewers:
+ sigmund@google.com

[sra1, 2016-09-07 16:54:38]

Patchset #1 (id:1) has been deleted

[sra1, 2016-09-07 16:55:49]

Description was changed from

==========
Another round of GVN is sometimes worthwhile after code motion

Code motion really should be integrated with of GVN, since GVN and
code motion generate opportunities for each other.  Looking at a
sample of functions it is rare that the extra phases execute solely
due to code motion, so I don't think this much of a compile-time risk.

This fixes some sad looking code from a pending CL.

Also fix a bug where conditional constant interceptors could be pessimised.



BUG=
==========

to

==========
Another round of GVN is sometimes worthwhile after code motion

Code motion really should be integrated with of GVN, since GVN and
code motion generate opportunities for each other.  Looking at a
sample of functions it is rare that the extra phases execute solely
due to code motion, so I don't think this much of a compile-time risk
and benchmarks back that up.

This fixes some sad looking code from a pending CL.
==========

[Siggi Cherem (dart-lang), 2016-09-07 17:30:03]

lgtm

[sra1, 2016-09-07 18:18:18]

Description was changed from

==========
Another round of GVN is sometimes worthwhile after code motion

Code motion really should be integrated with of GVN, since GVN and
code motion generate opportunities for each other.  Looking at a
sample of functions it is rare that the extra phases execute solely
due to code motion, so I don't think this much of a compile-time risk
and benchmarks back that up.

This fixes some sad looking code from a pending CL.
==========

to

==========
Another round of GVN is sometimes worthwhile after code motion

Code motion really should be integrated with of GVN, since GVN and
code motion generate opportunities for each other.  Looking at a
sample of functions it is rare that the extra phases execute solely
due to code motion, so I don't think this much of a compile-time risk
and benchmarks back that up.

This fixes some sad looking code from a pending CL.

R=sigmund@google.com

Committed:
https://github.com/dart-lang/sdk/commit/65efe1dc082abbf2b070403519f62311b0ee457b
==========

[sra1, 2016-09-07 18:18:19]

Committed patchset #1 (id:20001) manually as
65efe1dc082abbf2b070403519f62311b0ee457b (presubmit successful).