Re: [Caml-list] flambda optimizations depends on unrelated things

[David Allsopp <dra-news@metastack.com>]

Alexey Egorov wrote:
> Hello,
> 
> I'm trying hard to make efficient pure functional streams
> implementation - and while playing with flambda, I'm discovered that
> optimizations is VERY fragile and sometimes depends on completely
> unrelated things.
> 
> Sometimes flambda goes mad if you change filename or just add some
> empty lines to your source.
> 
> Here is example, where renaming source file increases code size by a
> factor of 2 because of some unfortunate inliner decisions:
> 
> $ ls
> fragile.ml
> $ cp fragile.ml fragile2.ml
> $ md5sum *
> 6a13d560736c81b3e5b5dfe7f13c2f56 fragile2.ml
> 6a13d560736c81b3e5b5dfe7f13c2f56 fragile.ml
> $ ocamlopt -version
> 4.05.0
> $ ocamlopt -O3 fragile.ml -dflambda 2>&1 | wc -l
> 1774
> $ ocamlopt -O3 fragile2.ml -dflambda 2>&1 | wc -l
> 3835
> 
> Here is the code - https://pastebin.com/Y1DDidyN

Please could you file a report on Mantis? https://caml.inria.fr/mantis


David