[ruby-core:119613] [Ruby master Misc#20814] iseq optimizations on constant condition

[ruby-core:119613] [Ruby master Misc#20814] iseq optimizations on constant condition

[hurricup (Alexandr Evstigneev) via ruby-core]

Issue #20814 has been reported by hurricup (Alexandr Evstigneev).

----------------------------------------
Misc #20814: iseq optimizations on constant condition
https://bugs.ruby-lang.org/issues/20814

* Author: hurricup (Alexandr Evstigneev)
* Status: Open
----------------------------------------
ruby 3.4-preview2 seems optimizes out some stuff when building iseq and this may lead to user unexpected behavior when debugging, because some lines just optimized out. 

Example:
```
def foo1
  if true
    nil
  else
    1
  end
end
```

produces:
```
== disasm: #<ISeq:foo1@/test.rb:1 (1,0)-(7,3)>
0000 putnil                                                           (   3)[LiCa]
0001 leave                                                            (   7)[Re]
```

Two questions:
- is there way to disable such optimizations?
- are there some specs on things that can be optimized.



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[ruby-core:119616] [Ruby master Misc#20814] iseq optimizations on constant condition

[nobu (Nobuyoshi Nakada) via ruby-core]

Issue #20814 has been updated by nobu (Nobuyoshi Nakada).

Status changed from Open to Feedback

Because of the dynamic feature of Ruby, the optimization on ISeq is very limited.
For instance, elimination of unreachable branch because of a simple always-true/false condition expression, in your example.

> - is there way to disable such optimizations?

To disable optimizations, see the document of `RubyVM::InstructionSequence.compile_option=`.
https://docs.ruby-lang.org/en/master/RubyVM/InstructionSequence.html#method-c-compile_option-3D

> - are there some specs on things that can be optimized.

We do not provide explicit documentation or specifications regarding optimizations because they are internal features and may change without notice.

----------------------------------------
Misc #20814: iseq optimizations on constant condition
https://bugs.ruby-lang.org/issues/20814#change-110238

* Author: hurricup (Alexandr Evstigneev)
* Status: Feedback
----------------------------------------
ruby 3.4-preview2 seems optimizes out some stuff when building iseq and this may lead to user unexpected behavior when debugging, because some lines just optimized out. 

Example:
```
def foo1
  if true
    nil
  else
    1
  end
end
```

produces:
```
== disasm: #<ISeq:foo1@/test.rb:1 (1,0)-(7,3)>
0000 putnil                                                           (   3)[LiCa]
0001 leave                                                            (   7)[Re]
```

Two questions:
- is there way to disable such optimizations?
- are there some specs on things that can be optimized.



-- 
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 ______________________________________________
 ruby-core mailing list -- ruby-core@ml.ruby-lang.org
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[ruby-core:119617] [Ruby master Misc#20814] iseq optimizations on constant condition

[nobu (Nobuyoshi Nakada) via ruby-core]

Issue #20814 has been updated by nobu (Nobuyoshi Nakada).

Description updated

hurricup (Alexandr Evstigneev) wrote:
> ruby 3.4-preview2 seems optimizes out some stuff when building iseq and this may lead to user unexpected behavior when debugging, because some lines just optimized out. 
> 
> Example:
> ```
> def foo1
>   if true
>     nil
>   else
>     1
>   end
> end
> ```
> 
> produces:
> ```
> == disasm: #<ISeq:foo1@/test.rb:1 (1,0)-(7,3)>
> 0000 putnil                                                           (   3)[LiCa]
> 0001 leave                                                            (   7)[Re]
> ```
> 
> Two questions:
> - is there way to disable such optimizations?
> - are there some specs on things that can be optimized.



----------------------------------------
Misc #20814: iseq optimizations on constant condition
https://bugs.ruby-lang.org/issues/20814#change-110239

* Author: hurricup (Alexandr Evstigneev)
* Status: Feedback
----------------------------------------
ruby 3.4-preview2 seems optimizes out some stuff when building iseq and this may lead to user unexpected behavior when debugging, because some lines just optimized out. 

Example:
```ruby
def foo1
  if true
    nil
  else
    1
  end
end
```

produces:
```
== disasm: #<ISeq:foo1@/test.rb:1 (1,0)-(7,3)>
0000 putnil                                                           (   3)[LiCa]
0001 leave                                                            (   7)[Re]
```

Two questions:
- is there way to disable such optimizations?
- are there some specs on things that can be optimized.



-- 
https://bugs.ruby-lang.org/
 ______________________________________________
 ruby-core mailing list -- ruby-core@ml.ruby-lang.org
 To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
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[ruby-core:119635] [Ruby master Misc#20814] iseq optimizations on constant condition

[hurricup (Alexandr Evstigneev) via ruby-core]

Issue #20814 has been updated by hurricup (Alexandr Evstigneev).


nobu (Nobuyoshi Nakada) wrote in #note-1:
> To disable optimizations, see the document of `RubyVM::InstructionSequence.compile_option=`.
> https://docs.ruby-lang.org/en/master/RubyVM/InstructionSequence.html#method-c-compile_option-3D

My question is more about the runtime. E.g I want to run a ruby program with optimizations disabled at all. Or load using `rb_load`/`rb_load_protect` while ruby process is already alive with default settings.


----------------------------------------
Misc #20814: iseq optimizations on constant condition
https://bugs.ruby-lang.org/issues/20814#change-110288

* Author: hurricup (Alexandr Evstigneev)
* Status: Feedback
----------------------------------------
ruby 3.4-preview2 seems optimizes out some stuff when building iseq and this may lead to user unexpected behavior when debugging, because some lines just optimized out. 

Example:
```ruby
def foo1
  if true
    nil
  else
    1
  end
end
```

produces:
```
== disasm: #<ISeq:foo1@/test.rb:1 (1,0)-(7,3)>
0000 putnil                                                           (   3)[LiCa]
0001 leave                                                            (   7)[Re]
```

Two questions:
- is there way to disable such optimizations?
- are there some specs on things that can be optimized.



-- 
https://bugs.ruby-lang.org/
 ______________________________________________
 ruby-core mailing list -- ruby-core@ml.ruby-lang.org
 To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
 ruby-core info -- https://ml.ruby-lang.org/mailman3/lists/ruby-core.ml.ruby-lang.org/