FloatRep and DoubleRep ADT Argument in STG

[Csaba Hruska]

Hello,

I have to apologize because I've fooled myself. Everything works fine in
the Haskell side.
The problem was that I tried to pass a float value to printf which is a
variadic C function.
According to the C standard / stack overflow:

> * because printf and its friends are variadic functions, so a float
> parameter undergoes automatic conversion to double as part of the default
> argument promotions (see section 6.5.2.2 of the C99 standard).*
>

Sorry for the confusion.
Thanks,
Csaba

On Wed, Jan 22, 2020 at 10:27 PM Csaba Hruska <csaba.hruska at gmail.com>
wrote:

> I added Stg and Cmm linter to my custom pipeline and they report no errors.
>
> On Wed, Jan 22, 2020 at 4:40 PM Csaba Hruska <csaba.hruska at gmail.com>
> wrote:
>
>> Here are the pretty printed STG in GHC syntax:
>>
>> *WORKING (DoubleRep): prints 3.14*
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> *x0 :: Any[GblId] =    "Value: MyConA %d %d\n"#;x1 :: Any[GblId] =
>> "Value: MyConB %lf\n"#;main :: Any[GblId] =    [] \u [void_0E]        case
>> MyConB [3.14##] of x100 {          __DEFAULT ->              case x100 of
>> x101 {                MyConA x200 x202 -> __pkg_ccall [x0 x200 x202];
>>           MyConB x203 -> __pkg_ccall [x1 x203];              };        };*
>>
>>
>> *WRONG (FloatRep) : prints 0.00 instead of 3.14*
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> *x0 :: Any[GblId] =    "Value: MyConA %d %d\n"#;x1 :: Any[GblId] =
>> "Value: MyConB %f\n"#;main :: Any[GblId] =    [] \u [void_0E]        case
>> MyConB [3.14#] of x100 {          __DEFAULT ->              case x100 of
>> x101 {                MyConA x200 x202 -> __pkg_ccall [x0 x200 x202];
>>           MyConB x203 -> __pkg_ccall [x1 x203];              };        };*
>> Thanks,
>> Csaba
>>
>> On Wed, Jan 22, 2020 at 4:21 PM Csaba Hruska <csaba.hruska at gmail.com>
>> wrote:
>>
>>> Sorry, I should have noted that the gist has a description comment at
>>> the bottom.
>>>
>>> https://gist.github.com/csabahruska/e9e143390c863f7b10b0298a7ae80ac1#gistcomment-3148797
>>>
>>>
>>> On Wed, Jan 22, 2020 at 3:21 PM Ömer Sinan Ağacan <omeragacan at gmail.com>
>>> wrote:
>>>
>>>> What is the problem you're having? What do you mean by "run into
>>>> problems"?
>>>> What's going wrong?
>>>>
>>>> It'd be helpful if you could show us your program in STG syntax.
>>>>
>>>> > Is it valid to use FloatRep argument in a boxed ADT on 64 bit?
>>>>
>>>> It should be valid, yes.
>>>>
>>>> I'd also try with `-dstg-lint -dcmm-lint`.
>>>>
>>>> Ömer
>>>>
>>>> Csaba Hruska <csaba.hruska at gmail.com>, 22 Oca 2020 Çar, 14:56
>>>> tarihinde şunu yazdı:
>>>> >
>>>> > Hello,
>>>> >
>>>> > I try to use GHC backend via STG. For that reason I build small STG
>>>> program AST maually. So far the generated programs worked fine
>>>> (compile/link/run).
>>>> > However I run into problems when a lifted ADT has a FloatRep argument.
>>>> > Interestingly it works for DoubleRep.
>>>> > I'm using GHC 8.6.1 64 bit to generate the code for the constructed
>>>> STG AST.
>>>> > I wonder if I break an invariant or is this actually a bug?
>>>> > Is it valid to use FloatRep argument in a boxed ADT on 64 bit?
>>>> > I made a gist with the Haskell source and the generated Cmm code is
>>>> also included.
>>>> >
>>>> > https://gist.github.com/csabahruska/e9e143390c863f7b10b0298a7ae80ac1
>>>> >
>>>> > Working program (DoubleRep):
>>>> >
>>>> https://gist.github.com/csabahruska/e9e143390c863f7b10b0298a7ae80ac1#file-stgsample-hs-L134-L198
>>>> >
>>>> > Wrong program (FloatRep):
>>>> >
>>>> https://gist.github.com/csabahruska/e9e143390c863f7b10b0298a7ae80ac1#file-stgsample-hs-L64-L132
>>>> >
>>>> > Thanks,
>>>> > Csaba
>>>> >
>>>> >
>>>> > _______________________________________________
>>>> > ghc-devs mailing list
>>>> > ghc-devs at haskell.org
>>>> > http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
>>>>
>>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/ghc-devs/attachments/20200123/06f5c2ab/attachment.html>