[Mesa-users] How I succeeded in building Mesa llvmpipe 64-bit on Windows

[Brian Paul]

On 10/29/2012 10:20 AM, Charlie Charsie wrote:
> Dear list,
>
> I successfully built llvmpipe on Windows with native Visual Studio 2008sp1, and wanted to share my experiences.

If you think that some of this information should be rolled into the 
Mesa documentation, please submit some patches to do so.


> Most I did was 64-bit, however, it should work for 32-bit compile settings, also.
>
> Requirements:
> - Python 2.7 (32-bit)
> - SCons 2.2
> - CMake
> - MSYS, e.g. provided by MinGW. Including Flex&  Bison. MSYS Console: "mingw-get install msys-flex msys-bison", and environment path modified respectively (e.g. "PATH=...;C:\MinGW\msys\1.0\bin;").
>
> MESA 8.0.2 with LLVM 2.9
> ------------------------
> Start with LLVM:
> - LLVM required patch source code a bit in prior: http://llvm.org/bugs/show_bug.cgi?id=9976 , and http://llvm.org/bugs/attachment.cgi?id=6634
> - Use Cmake to configure, runtime libraries linked with /MT (statically)
> - Define Install target in CMake and install binaries after build.
> - Set install path on environment: "SET LLVM=C:\MyLLVMInstall"
>
> MESA:
> - Visual Studio 64 Bit doesn't like DLL exports by DEF file AND by declspec. Modify include/gl.h around ~ line 56: # define GLAPI /*declspec(dllexport)*/

I'd be hesitant to do that unconditionally in Mesa because it might 
break something else.  Maybe there should be some sort of #ifdef 
around that change.


> - Open Visual Studio x64 command prompt
> - Invoke build by: c:\python27\scons.bat build=release llvm=yes platform=windows machine=x86_64 libgl-gdi
>
>
> MESA 9.0 with LLVM 3.1
> ----------------------
> - Works quite the same way without having to patch LLVM.
>
>
> MESA 8.0.5 with LLVM 2.9
> ------------------------
> - Got a compile error in shaderobj.c (~280), after defining the unsigned int in a different way, compile succeeds. However:

Please post your patch for this so we can fix it.  But I've been 
building Mesa on Windows and don't recall seeing a problem there.


> - DLL crashes after about 100 rendered frames all the time - don't know why.
>
> I tried native MinGW
> --------------------
> - I installed 64 bit from http://tdm-gcc.tdragon.net/download (experimental)
> - I invoked build process by calling: c:\python27\scons.bat build=release llvm=yes platform=windows toolchain=mingw machine=x86_64 libgl-gdi
>
> Result: Initially, SCons always tried to use the VC compiler, after setting all up on a different VM, I ended in the well-known "command line too long" problem (http://scons.tigris.org/ds/viewMessage.do?dsForumId=1272&dsMessageId=883411)
>
> I see no solution to this without having the Mesa Developers to take care of it in their built solution.
>
> I tried cross-compile using Ubuntu
> ----------------------------------
> - different way to tell mesa the LLVM root, try: "export LLVM=/home/myLLVMInstall" or "export LLVM_ROOT=/home/myLLVMInstall"
> - I got compile errors, maybe related to https://bugs.freedesktop.org/show_bug.cgi?id=44618
>
>
> FURTHER TIPS
> ------------
>
> - So far no success in using the software rasterizer of mesa, DLL crashes on use
> - OSMesa exports all symbols under windows - So far, I cannot use it along with llvmpipe.

Yeah, there's no support for OSMesa + llvmpipe.


>
> - On all tested systems, CPU resources have not been exhausted properly by llvmpipe. However, performance much better compared to Microsoft software renderer.
>
> - On some tested systems, performance was unequivocal slow. After disabling the LLVM threader (Env. var. LP_NUM_THREADS = 0), performance again was as expected with this setting.

Are those systems single core or what?


> - VS 2010 might also work, but VS 2012 struggles with compiler keywords.

Can you be more specific?


>
> LINKS
> -----
>
> Some links that might be helpful (not all emerged to be correct though):
> http://phoronix.com/forums/showthread.php?72780-LLVMpipe-On-Mesa-8-1-Performance
> http://www.phoronix.com/scan.php?page=article&item=llvmpipe_snb_bulldozer&num=2
> http://www.phoronix.com/scan.php?page=news_item&px=MTA5ODc
> https://sites.google.com/site/buildllvmpipe/
>
>
> Hope that helps.
>
> Best,
> MB
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-Brian