[VM-Compiler] Don't inline if we don't have inlining budget enough to fully inline.

[VM-Compiler] Don't inline if we don't have inlining budget enough to fully inline.

When deciding whether to inline a function that has already been optimized
once, take a look at how many levels of inlining took place when it was
optimized stand-alone. If we don't have that much depth budget left, don't
inline.  This is an attempt to avoid the situation where we inline a function
that was already optimized, and then fail to inline important things that are
in the inner loop.

The benchmarking server shows about a 3% improvement on average when running
the DartJS compiler

R=vegorov@google.com
BUG=

[Vyacheslav Egorov (Google), 2017-09-04 12:14:31]

lgtm

https://codereview.chromium.org/2994283002/diff/1/runtime/vm/flow_graph_inlin...
File runtime/vm/flow_graph_inliner.cc (right):

https://codereview.chromium.org/2994283002/diff/1/runtime/vm/flow_graph_inlin...
runtime/vm/flow_graph_inliner.cc:628: bool ShouldWeInline(const Function&
callee,
I better way would be to have all results coupled together as a struct:

struct InliningDecision {
  bool inline;
  const char* reason;

  static InliningDecision Yes(const char*) { return InliningDecision(true, ...)
};
  static InliningDecision No(const char*) { return InliningDecision(true, ...)
};
};

...

  return InliningDecision::Yes("AlwaysInline")

[Vyacheslav Egorov (Google), 2017-09-07 07:48:04]

ping

[erikcorry, 2017-09-21 08:12:19]

https://codereview.chromium.org/2994283002/diff/1/runtime/vm/flow_graph_inlin...
File runtime/vm/flow_graph_inliner.cc (right):

https://codereview.chromium.org/2994283002/diff/1/runtime/vm/flow_graph_inlin...
runtime/vm/flow_graph_inliner.cc:628: bool ShouldWeInline(const Function&
callee,
On 2017/09/04 12:14:31, Vyacheslav Egorov (Google) wrote:
> I better way would be to have all results coupled together as a struct:
> 
> struct InliningDecision {
>   bool inline;
>   const char* reason;
> 
>   static InliningDecision Yes(const char*) { return InliningDecision(true,
...)
> };
>   static InliningDecision No(const char*) { return InliningDecision(true, ...)
> };
> };
> 
> ...
> 
>   return InliningDecision::Yes("AlwaysInline")
> 

Done.

[aryanarya2619, 2017-09-21 08:55:03]

https://vootapp.in/