Add --noopt flag that sets all kind of flags to make unoptimzied code as fast as possible (and not …

Add --noopt flag that sets all kind of flags to make unoptimzied code as fast as possible (and not running optimized code at all).
Add flag --always_megamorphic_calls, causes instance calls to use megamorphic instead of ICdata calls.

R=fschneider@google.com

Committed: https://code.google.com/p/dart/source/detail?r=45475

[srdjan, 2015-05-01 20:32:43]

srdjan@google.com changed reviewers:
+ fschneider@google.com

[Florian Schneider, 2015-05-01 20:47:58]

lgtm

https://codereview.chromium.org/1119013003/diff/60001/runtime/vm/flow_graph_c...
File runtime/vm/flow_graph_compiler.cc (right):

https://codereview.chromium.org/1119013003/diff/60001/runtime/vm/flow_graph_c...
runtime/vm/flow_graph_compiler.cc:63: FLAG_optimization_counter_threshold = -1;
Will this handler called ever with (value == false)?

Maybe do:

if (value) {
  FLAG_always_megamorphic_calls = true;
  FLAG_optimization_counter_threshold = -1;
  FLAG_use_field_guards = false;
}

https://codereview.chromium.org/1119013003/diff/60001/runtime/vm/flow_graph_c...
runtime/vm/flow_graph_compiler.cc:64: FLAG_use_field_guards = false;
FLAG_use_osr = false;

to avoid generating OSR checking code?

https://codereview.chromium.org/1119013003/diff/60001/runtime/vm/flow_graph_c...
runtime/vm/flow_graph_compiler.cc:68: // --unopt disables optimizer and tunes
unoptimized code to run as fast
s/unopt/noopt/

[srdjan, 2015-05-01 20:55:11]

https://codereview.chromium.org/1119013003/diff/60001/runtime/vm/flow_graph_c...
File runtime/vm/flow_graph_compiler.cc (right):

https://codereview.chromium.org/1119013003/diff/60001/runtime/vm/flow_graph_c...
runtime/vm/flow_graph_compiler.cc:63: FLAG_optimization_counter_threshold = -1;
On 2015/05/01 20:47:58, Florian Schneider wrote:
> Will this handler called ever with (value == false)?
> 
> Maybe do:
> 
> if (value) {
>   FLAG_always_megamorphic_calls = true;
>   FLAG_optimization_counter_threshold = -1;
>   FLAG_use_field_guards = false;
> }

Done.

https://codereview.chromium.org/1119013003/diff/60001/runtime/vm/flow_graph_c...
runtime/vm/flow_graph_compiler.cc:64: FLAG_use_field_guards = false;
On 2015/05/01 20:47:58, Florian Schneider wrote:
> FLAG_use_osr = false;
> 
> to avoid generating OSR checking code?

Done.

https://codereview.chromium.org/1119013003/diff/60001/runtime/vm/flow_graph_c...
runtime/vm/flow_graph_compiler.cc:68: // --unopt disables optimizer and tunes
unoptimized code to run as fast
On 2015/05/01 20:47:58, Florian Schneider wrote:
> s/unopt/noopt/

Done.

[srdjan, 2015-05-01 20:55:34]

Committed patchset #5 (id:80001) manually as r45475 (presubmit successful).