[LLVMdev] JIT on ARM

[Jim Grosbach]

Hi Martins,

There's two steps to get where you're wanting to go.

First, you need an ARM cross-compiler on your host so you can generate  
ARM bitcode. That's what you're building with your llvm-gcc you  
referenced. In my ARM configure lines, I explicitly specify --host and  
--build as well as --target, but that is more due to vagaries of my  
local environment and shouldn't be required for what you're doing.

Second, you need an ARM *hosted* LLVM build to actually do the JIT  
execution of the bytecode you've produced on the host. For that,  
you'll need a canadian-cross compile build of llvmCore. Have a  
separate objects build directory for llvm than you use for cross  
compiler since this will be ARM code, not x86 code. Specify "-- 
host=arm-eabi --build=i686-pc-cygwin --target=arm-eabi" on your  
configure line, and you should be able to generate an ARM-hosted LLVM  
toolset. Do note that this will require a set of ARM-target cross  
compiler tools to be on the path and ARM libraries to be available,  
just like building any other ARM code on your host. You'll see the  
configure script looking for tools like "arm-eabi-gcc" and such,  
probably. If it can't find them, things are unlikely to work.

Once you've built the ARM hosted LLVM, you can copy it over to your  
device (I NFS mount the directory, personally). Then you can run lli  
from there on bitcode and the ARM JIT should kick in and compile your  
code.

The errors you're seeing don't look familiar to me, unfortunately.   
lexer_line is defined in gengtype-lex.l. Perhaps there were issues  
running flex to generate the code from there? I would suggest looking  
in your build logs for where gengtype-lex.c and gengtype-lex.o are  
created to see if there are earlier problems that cascaded down to  
result in this link failure.

Regards,
   Jim

On Sep 25, 2009, at 2:04 AM, Martins Mozeiko wrote:

> Hello.
>
> My goal is to use LLVM with JIT compiler for ARM on Android device.
>
> Currently I have successfully built and executed LLVM bitcode with
> interpreter on Android. Speed is not so great, that is why I want to
> use JIT.
> I tried building bitcode on windows with llvm-gcc that is provided on
> llvm home page. Resulting bitcode runs great in interpreter, but it
> doesn't use JIT. From what I understand from LLVM that it is because
> of target triple or datalayout. On PC in my case target triple is
> "i386-mingw32", but LLVM JIT for ARM expects something that starts
> with "armv" or "thumb". Also datalayout differs a lot. If I understand
> correctly that is because bitcode actually contains some of platform
> specific optimizations (like integer endianness), so I can't simply
> change target triple string and everything will run.
>
> What I am now doing, is - I am trying to build gcc from gcc-4.2-
> llvm-2.5 sources with following configure line in cygwin shell:
>
> ../llvm-gcc4.2-2.4.source/configure --enable-languages=c,c++ --enable-
> checking --enable-llvm=$PWD/../llvm-objects --disable-bootstrap --
> disable-multilib --disable-nls --target=arm-eabi
>
> My undertanding is that this will produce llvm-gcc compiler that will
> output LLVM bitcode with target triple that starts with "arm", so LLVM
> will use JIT on it.
>
> Currently I am getting compile problems when running make (see below).
> Has anyone done something similar and can explain what I am doing
> wrong, or how should it be done in some other way to get JIT compiler
> running on ARM?
>
>
> make[2]: Entering directory `/cygdrive/r/android/llvm/llvm-gcc4.2-
> objects/gcc'
> gcc   -g -O2 -DIN_GCC -DCROSS_DIRECTORY_STRUCTURE  -W -Wall -Wwrite-
> strings -Wstrict-prototypes -Wmissing-prototypes -pedantic -Wno-long-
> long -Wno-variadic-macros -Wno-overlength-strings -Wold-style-
> definition -Wmissing-format-attribute -fno-common   -DHAVE_CONFIG_H -
> DGENERATOR_FILE  -o build/gengtype.exe \
>             build/gengtype.o build/gengtype-lex.o build/gengtype-
> yacc.o build/errors.o ../build-i686-pc-cygwin/libiberty/libiberty.a
> build/gengtype.o: In function `adjust_field_type':
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype.c:763: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype.c:771: undefined reference to
> `_lexer_line'
> build/gengtype.o: In function `adjust_field_tree_exp':
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype.c:713: undefined reference to
> `_lexer_line'
> build/gengtype.o: In function `adjust_field_rtx_def':
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype.c:488: undefined reference to
> `_lexer_line'
> build/gengtype.o: In function `adjust_field_type':
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype.c:785: undefined reference to
> `_lexer_line'
> build/gengtype.o:/cygdrive/r/android/llvm/llvm-gcc4.2-objects/
> gcc/../../llvm-gcc4.2-2.4.source/gcc/gengtype.c:725: more undefined
> references to `_lexer_line' follow
> build/gengtype.o: In function `main':
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype.c:3070: undefined reference to
> `_parse_file'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype.c:3070: undefined reference to
> `_parse_file'
> build/gengtype-yacc.o: In function `yyparse':
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:73: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:75: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:76: undefined reference to
> `_lexer_toplevel_done'
> build/gengtype-yacc.o: In function `yyparse':
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/gengtype-yacc.c:1873:
> undefined reference to `_yyerror'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/gengtype-yacc.c:1379:
> undefined reference to `_yylex'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/gengtype-yacc.c:1877:
> undefined reference to `_yyerror'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/gengtype-yacc.c:1995:
> undefined reference to `_yyerror'
> build/gengtype-yacc.o: In function `yyparse':
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:122: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:110: undefined reference to
> `_lexer_toplevel_done'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:102: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:97: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:92: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:239: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:235: undefined reference to
> `_lexer_line'
> build/gengtype-yacc.o:/cygdrive/r/android/llvm/llvm-gcc4.2-objects/
> gcc/../../llvm-gcc4.2-2.4.source/gcc/gengtype-yacc.y:231: more
> undefined references to `_lexer_line' follow
> build/gengtype-yacc.o: In function `yyparse':
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:84: undefined reference to
> `_lexer_toplevel_done'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:203: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:203: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:176: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:176: undefined reference to
> `_lexer_line'
> /cygdrive/r/android/llvm/llvm-gcc4.2-objects/gcc/../../llvm-
> gcc4.2-2.4.source/gcc/gengtype-yacc.y:165: undefined reference to
> `_lexer_line'
> build/gengtype-yacc.o:/cygdrive/r/android/llvm/llvm-gcc4.2-objects/
> gcc/../../llvm-gcc4.2-2.4.source/gcc/gengtype-yacc.y:165: more
> undefined references to `_lexer_line' follow
> collect2: ld returned 1 exit status
> make[2]: *** [build/gengtype.exe] Error 1
>
> --
> Martins Mozeiko
>
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