[LLVMdev] RFC: Machine Level IR text-based serialization format

[Krzysztof Parzyszek]

On 4/28/2015 7:13 PM, Alex L wrote:
>
>
> 2015-04-28 16:26 GMT-07:00 Matthias Braun <matze at braunis.de
> <mailto:matze at braunis.de>>:
>
>     For that use case it is worth keeping the following things in mind:
>     - Please try to keep the output of the various dump functions, esp.
>     MachineInstr::dump(), MachineOperand::dump(),
>     MachineBasicBlock::dump() as close as possible to the format you use
>     for serializing.
> [...]
>
> Ideally the new syntax would replace the existing print/dump syntax. The
> new syntax will lead to certain missing information when
> this information can be inferred (e.g. the TiedTo and IsEarlyClobber
> attributes for register operands that I mentioned earlier in this thread),
> so maybe we could have some sort of verbose dumping option where
> absolutely everything is dumped.


I think that the new syntax is less readable than the current format of 
the "dump" functions, and in the long term it would be better to have 
something more human-friendly.  However, using YAML has the advantage 
that it's easier to parse it than the direct output of "dump" and so it 
will take less time to implement a YAML-based solution.  My concern is 
that you may run out of time to complete this and the file format is not 
the most important thing in this project.  Getting it to work, if only 
as a proof of concept, would be very helpful to everyone.  Coming up 
with a fancier grammar and implementing a parser for it could be done 
later on top of the initial implementation.

-Krzysztof

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