[LLVMdev] GCC3.5 tree-ssa

[yue]

we work on distribute software development, most programs are wroten in 
java.
but the running speed of that is slowly,  it requires thread library to 
support, you know.

Chris Lattner wrote:

>On Wed, 24 Dec 2003, yue wrote:
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>  
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>>why doesn't llvm transfer bytecode to RTL form? I mean the
>>cross-platform compile in GCC. Could LLVM do that?
>>    
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>
>Sure, it would be a realtively straight-forward (but large and hard to get
>right, if you're not a GCC expert), project to build an LLVM front-end for
>GCC.  This would allow you to effectively use LLVM as a mid-level
>representation for GCC, and would allow you to use all of the GCC
>back-ends with LLVM.
>
>However, note that LLVM already does have a C backend, which allows you to
>interface the LLVM optimizer to GCC or any other platform compiler.  This
>effectively gives you most of the advantages of a real "RTL backend", with
>the added advantage that we support the Intel, Sun, SGI, etc compilers as
>well (at least in theory, we have only tried compiling the CBE output with
>the GCC and Intel compilers).  Also "C" is a very stable interface
>language, where the RTL interfaces and APIs are constantly changing.  The
>one advantage an RTL backend would have over the C backend is speed of
>compilation.
>
>  
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>>maybe tree-ssa also create the representation with a testual format if
>>needed. is it very difficalt? I want to know.
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>There are _very strong_ political reasons that will prevent this from
>happening any time in the near future.  I suggest that you ask on the GCC
>list if you want more details.  All tree-ssa supports are some debugging
>dumps, which do not contain all of the information needed for compilation.
>
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>>BWT: if we port pthread library to llvm, what do we consider at first?
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>I'm not sure exactly what you mean.  If it's written in C, you should be
>able to just compile it with LLVM as you would any other program or
>library.  Have you run into a problem or bug?
>
>-Chris
>
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>>Chris Lattner wrote:
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>>>On Wed, 24 Dec 2003, yue wrote:
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>>>>what difference is between gcc3.5 tree-ssa and llvm?
>>>>
>>>>
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>>>>
>>>They are completely different projects.  The short version is that LLVM is
>>>more mature and stable than tree-ssa is, LLVM supports interprocedural and
>>>runtime optimization, and LLVM has a well defined intermediate
>>>representation with a textual format.  On the other hand tree-ssa may be a
>>>part of GCC 3.5 someday once it has stabilized and enough bugs have been
>>>fixed.  Oh, LLVM is written in C++ and tree-ssa is written in C.
>>>
>>>If there is something more specific you want to know, please ask.  It's
>>>very much the difference between apples and oranges.
>>>
>>>-Chris
>>>
>>>
>>>
>>>      
>>>
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>-Chris
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