Hi all,
the CallGraph pass is only available in opt. Is there any substantial reason
for that? Or is it only because it seems not to be useful for llc?
I want to use it in an backend that is derived from the CBackend. I need the
information what functions are called in every other function to build
communication struktures between the functions. The backend is generating
VHDL from C code. (VHDL is a hardware description language, which means it is
used to generate hardware, for those who are not familiar with this.)
I've managed to compile my backend with the CallGraph pass, but when it try to
use it, I get an error, which I could't fix until now.
llc --load=/home/paul/LLVM/install/llvm-2.2/lib/MParSchedule.so --load=/home/paul/LLVM/install/llvm-2.2/lib/libLLVMVHDLBackend.so -f -march=vhdl
test.o -o llvm.vhd
llc: /home/paul/LLVM/src/llvm-2.2/lib/VMCore/PassManager.cpp:922: virtual void
llvm::PMDataManager::addLowerLevelRequiredPass(llvm::Pass*, llvm::Pass*):
Assertion `0 && "Unable to handle Pass that requires lower level Analysis
pass"' failed.
llc[0x85e922c]
/lib/i686/cmov/libc.so.6(abort+0x101)[0x401e6981]
/lib/i686/cmov/libc.so.6(__assert_fail+0xee)[0x401de10e]
llc(llvm::PMDataManager::addLowerLevelRequiredPass(llvm::Pass*,
llvm::Pass*)+0x7d)[0x857da0d
I'm suspecting the reason for the error is connected with the reason that
caused to make CallGraph a opt only pass.
Thanks for your time !
- Paul
Paul,
Hi all,
the CallGraph pass is only available in opt. Is there any substantial reason
for that? Or is it only because it seems not to be useful for llc?
No, that's not true.
I want to use it in an backend that is derived from the CBackend. I need the
information what functions are called in every other function to build
communication struktures between the functions. The backend is generating
VHDL from C code. (VHDL is a hardware description language, which means it is
used to generate hardware, for those who are not familiar with this.)
I've managed to compile my backend with the CallGraph pass, but when it try to
use it, I get an error, which I could't fix until now.
llc --load=/home/paul/LLVM/install/llvm-2.2/lib/MParSchedule.so --load=/home/paul/LLVM/install/llvm-2.2/lib/libLLVMVHDLBackend.so -f -march=vhdl
test.o -o llvm.vhd
llc: /home/paul/LLVM/src/llvm-2.2/lib/VMCore/PassManager.cpp:922: virtual void
llvm::PMDataManager::addLowerLevelRequiredPass(llvm::Pass*, llvm::Pass*):
Assertion `0 && "Unable to handle Pass that requires lower level Analysis
pass"' failed.
llc[0x85e922c]
/lib/i686/cmov/libc.so.6(abort+0x101)[0x401e6981]
/lib/i686/cmov/libc.so.6(__assert_fail+0xee)[0x401de10e]
llc(llvm::PMDataManager::addLowerLevelRequiredPass(llvm::Pass*,
llvm::Pass*)+0x7d)[0x857da0d
This error indicates that pass manager is not able to schedule your pass.
918 // Module Level pass may required Function Level analysis info
919 // (e.g. dominator info). Pass manager uses on the fly function pass manager
920 // to provide this on demand. In that case, in Pass manager terminology,
921 // module level pass is requiring lower level analysis info managed by
922 // lower level pass manager.
923
924 // When Pass manager is not able to order required analysis info, Pass manager
925 // checks whether any lower level manager will be able to provide this
926 // analysis info on demand or not.
927 assert (0 && "Unable to handle Pass that requires lower level Analysis pass");
What is the skeleton of your pass structure ?
Use -debug-pass=? argument on the llc command line to understand what pass manager is trying to do. Try 'llc --help-hidden' for more info.
Hi Paul,
> Assertion `0 && "Unable to handle Pass that requires lower level
> Analysis
> pass"' failed.
I have been struggling with the same problem as well, when I wanted to make a
loop pass depend on a module pass (IIRC). You should probably pull your
program through gdb and get a backtrace so you can see what pass is causing
the problem.
Also, a paste of the passes you are trying to schedule would help as well (you
were building your own program, not using the builtin opt / llc / etc, right?
Gr.
Matthijs
I added small fix to make this assertion message more helpful. If you use --debug-pass=Details on the command line then pass manager will print information which may help you understand what is going on. If it is not clear, send me --debug-pass=Details output.