[GHC] #3814: Compile to more than one (sub)-architecture

[GHC]

#3814: Compile to more than one (sub)-architecture
---------------------------------+------------------------------------------
    Reporter:  filcab            |       Owner:                                
        Type:  feature request   |      Status:  new                           
    Priority:  normal            |   Component:  Compiler                      
     Version:  6.12.1            |    Keywords:  architecture, compiler, x86_64
          Os:  Unknown/Multiple  |    Testcase:                                
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown                  
---------------------------------+------------------------------------------
 GHC, as far as I can tell, can only compile files for one architecture
 (let's call it the "host architecture").

 This brings some problems... The biggest of which is that we lose the
 option of building for 32/64 bits in one of the "hybrid" architectures
 (For example, in x86_64-linux or i386-darwin)

 If I build a ghc in a x86_64 linux I will only get the x86_64 code
 generator and not the i386 generator. This will stop me from building a
 program which links with a library that only has a 32-bit version.
 If I want a GHC which will only compile for the i386, I will have to
 cross-compile, which is not very pretty.

 The same will happen on the Mac OS X side (even though the x86_64-darwin
 port is still on its way...).


 But GHC "should" (IMHO) be able to do like GCC and be able to generate
 code for both architecturess (i386 and x86_64), through the usage of
 compiler flags (which would also be passed to any gcc sub-process, if need
 be). At least if it is installed in a x86_64 (and PPC, if PPC64 is
 supported) system.


 Even better would be to do like LLVM's llc which enables a user to
 generate an assembly file for a target architecture from any other
 architecture.

 Example of an LLVM target list:
 filcab at fry:/stuff/src> llc --version
 Low Level Virtual Machine (http://llvm.org/):
   llvm version 2.7svn
   DEBUG build with assertions.
   Built Jan 10 2010 (00:25:59).
   Host: x86_64-unknown-linux-gnu
   Host CPU: core2

   Registered Targets:
     arm     - ARM
     c       - C backend
     cellspu - STI CBEA Cell SPU [experimental]
     cpp     - C++ backend
     mips    - Mips
     msil    - MSIL backend
     ppc64   - PowerPC 64
     sparc   - Sparc
     x86     - 32-bit X86: Pentium-Pro and above
     x86-64  - 64-bit X86: EM64T and AMD64

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3814>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler