Windows breakage -- again

[Austin Seipp]

Thanks Niklas, this is now committed.

On Fri, Jul 18, 2014 at 9:21 AM, Niklas Larsson <metaniklas at gmail.com> wrote:
> I posted a working and tested patch last night. Please feel free to commit
> it, I haven't the rights to do it.
>
> Niklas
> ________________________________
> Från: Simon Peyton Jones
> Skickat: ‎2014-‎07-‎18 15:55
> Till: Niklas Larsson; Johan Tibell
> Kopia: ghc-devs at haskell.org
> Ämne: RE: Windows breakage -- again
>
> Thank you all for pursuing this.  I gather that you know what is going on,
> so no further info needed from me.  Yell if it is otherwise.
>
>
>
> Meanwhile, is the fix imminent, or should we revert Johan’s patch?
>
>
>
> Simon
>
>
>
> From: Niklas Larsson [mailto:metaniklas at gmail.com]
> Sent: 16 July 2014 19:58
> To: Johan Tibell; Simon Peyton Jones
> Cc: ghc-devs at haskell.org
> Subject: Re: Windows breakage -- again
>
>
>
> I get the same failure when I try to build HEAD. Turns out the error occurs
> on the 32-bit Windows build, and my successful build was a 64-bit build. My
> 64-bit build still succeeds.
>
> Also, gcc is 4.5.2 on 32-bit, not 4.6.3 as on 64-bit.
>
> Niklas
>
>
>
>
>
> 2014-07-16 14:48 GMT+02:00 Niklas Larsson <metaniklas at gmail.com>:
>
> I have built ghc on windows after that was added with no issue.
>
> I can take a look this evening and  see how HEAD works for me.
>
> The standard gcc in the tarballs is 4.6.3, which is getting long in the
> tooth, there is an issue on trac to upgrade it.
>
> -- Niklas
>
> ________________________________
>
> Från: Johan Tibell
> Skickat: ‎2014-‎07-‎16 09:57
> Till: Simon Peyton Jones
> Kopia: ghc-devs at haskell.org
> Ämne: Re: Windows breakage -- again
>
> You can rollback the commit (git revert
> 4ee4ab01c1d97845aecb7707ad2f9a80933e7a49) and push that to the repo if you
> wish. I will try to re-add the primop again after I figure out what's wrong.
>
>
>
> On Wed, Jul 16, 2014 at 9:37 AM, Johan Tibell <johan.tibell at gmail.com>
> wrote:
>
> I added some primops about a month ago
> (4ee4ab01c1d97845aecb7707ad2f9a80933e7a49) that call __sync_fetch_and_add, a
> gcc/llvm builtin. I'm a bit surprised to see this error. The GCC manual [1]
> says:
>
>
>
>> " Not all operations are supported by all target processors. If a
>> particular operation cannot be implemented on the target processor, a
>> warning will be generated and a call an external function will be generated.
>> The external function will carry the same name as the builtin, with an
>> additional suffix `_n' where n is the size of the data type."
>
>
>
> I'm a bit surprised by this error for two reasons:
>
>
>
>  * A call to that symbol should only be generated if the CPU doesn't support
> the atomic instructions. What CPU model does Windows report that you have?
>
>
>
>  * gcc should define such a symbol. For me the following test program
> compiles:
>
>
>
> #include <stdint.h>
>
>
>
> uint8_t test(uint8_t* ptr, uint8_t val) {
>
>   return __sync_fetch_and_add_1(ptr, val);
>
> }
>
>
>
> int main(void) {
>
>   uint8_t n;
>
>   return test(&n, 1);
>
> }
>
>
>
> Does that compile for you? Which version of GCC do we end up using on
> Windows?
>
>
>
> The reported symbol (___sync_fetch_and_add_1) has three leading underscores,
> that looks weird. Can you compile just libraries/ghc-prim/cbits/atomic.c and
> see if it's indeed GCC that generates a reference to that symbol?
>
>
>
> 1. http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gcc/Atomic-Builtins.html
>
>
>
> On Wed, Jul 16, 2014 at 12:29 AM, Simon Peyton Jones <simonpj at microsoft.com>
> wrote:
>
> Aargh!  The Windows build has broken – again.  I can’t build GHC on my
> laptop any more.
>
>
> [Hela det ursprungliga meddelandet tas inte med.]
>
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>



-- 
Regards,

Austin Seipp, Haskell Consultant
Well-Typed LLP, http://www.well-typed.com/