https://github.com/adinapoli/ghc-unoptimised-core-binds-repro

https://github.com/adinapoli/ghc-unoptimised-core-binds-repro

Last synced: about 1 month ago
JSON representation

• Host: GitHub
• URL: https://github.com/adinapoli/ghc-unoptimised-core-binds-repro
• Owner: adinapoli
• Created: 2020-09-09T13:15:45.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2020-09-09T13:16:05.000Z (over 4 years ago)
• Last Synced: 2024-10-15T06:52:45.568Z (3 months ago)
• Language: Haskell
• Size: 3.91 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# Overview

This is a small Cabal project demonstrating that is not possible to extract the 'CoreBind' with

optimisations turned off in case things like `UNPACK` are used. Here is the testing scenario:

1. A "target" package that simply introduces a datatype with an unpacked field, and is

   compiled with `-O2`.

2. A 'ToyPlugin' GHC Plugin that modifies the GHC pipeline at the typechecking and core phases;

    a. During typechecking, we disable optimisations (we call `updOptLevel 0` on the `DynFlags`)

       and we call 'hscDesugar', hoping to get suitable binds;

    b. During core, we print the "standard" binds associated to the optimisation level for the

       user program (-O2).

    c. We print the binds of both phases.

One would expect that the generated Core to look something like that:

```

unFoo :: Foo -> Int

unFoo

  = \ (ds_d3hC :: Foo) -> case ds_d3hC of { Foo ds_d3hD -> ds_d3hD }

```

But we always get:

```

unFoo :: Foo -> Int

unFoo

  = \ (ds_d3pn :: Foo) -> case ds_d3pn of { Foo dt_d3pS -> I# dt_d3pS }

```