Re: [Haskell-cafe] Building Haskell Platform natively for 64bit Windows

It's worth mentioning 'foreign prim' is still a bit different from "inline" code - while you can certainly write Cmm and have GHC link it into your program, it is not really "inline." GHC has two different kinds of primitive operations: inline primops, and out of line primops. foreign primops are currently always out of line. Inline primops require actual GHC hacking, as they are short code sequences emitted directly by the code generator, that don't block or require allocation. As far as I know, GHC will naturally still generate a call to these out of line primops when you use them - in the form of a 'jmp' instruction, which is all that exists in Cmm (if someone out there knows more, like Johan perhaps who recently did memcpy inline primops, please correct me.) GHC will not necessarily have to spill STG registers (as it would in the case of a true foreign call,) but the instructions certainly won't be inline. Truthfully the use case for foreign prim is frighteningly small I think. It's been around for a while, but currently it's only client is integer-gmp, which was part of the motivation for the implementation anyway (to split GMP away from the GHC RTS, so it would be possibly to build full BSD3 haskell executables for commercial purposes, etc.) Outside of perhaps, an integer-openssl binding that instead used OpenSSL bignums, I can't think of many use cases personally. And a true 64bit GHC port to windows is of course, going to help the situation much more than any amount of hacking around the issue with 32bits and 8 registers will, while trying to retain some sense of efficiency. On Fri, Jun 10, 2011 at 12:16 PM, Andrew Coppin wrote:

On 10/06/2011 01:44 AM, Jason Dagit wrote:

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On Thu, Jun 9, 2011 at 2:06 PM, Andrew Coppin  wrote:

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Too bad GHC doesn't support inline assembly yet... (Or does it? I know it supports inline Core now.)

Really?  I found this in the manual so I think either the docs need to be updated or you are mistaken:

Apparently I am mistaken. It allows inline C-- (as of 6.12.1):

http://www.haskell.org/ghc/docs/6.12.1/html/users_guide/ffi.html#ffi-prim

Of course, C-- is not nearly the same as Core. Sorry about that...

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-- Regards, Austin