Hello,
in the implementation of some analysis, I need to change the program and then
invoke Mem2Reg pass. That pass, in turn, requires other analysis, so I must
use PassManager. Here's the code I ended up with:
1. This looks inefficient -- the analyses necessary for Mem2Reg will be run
again, even if they are already run by the global pass manager. But how to
ask the global pass manager to run a pass immediately?
2. This does not work. ExistingModuleProvider takes ownership of m.getParent()
and deletes it at the end.
3. This does not work. The Mem2Reg pass requires TargetData which does not
seem to be available. The only reason why it requires it, is to pass to
lib/Transforms/Utils/PromoteMemoryToRegister.cpp:isAllocaPromotable, which
does not use that data at all.
in the implementation of some analysis, I need to change the program and then
invoke Mem2Reg pass. That pass, in turn, requires other analysis, so I must
Usually you want to do this at a higher level, why not just use 'opt
-yourpass -mem2reg'?
Alternatively, if you don't want to do that, you can build mem2reg into
your pass if it works better. To do this, your pass needs to
'addRequired' DominatorTree and DominatorFrontier, then use the
interfaces exposed through
include/llvm/Transforms/Utils/PromoteMemToReg.h.
1. This looks inefficient -- the analyses necessary for Mem2Reg will be run
again, even if they are already run by the global pass manager. But how to
ask the global pass manager to run a pass immediately?
2. This does not work. ExistingModuleProvider takes ownership of m.getParent()
and deletes it at the end.
3. This does not work. The Mem2Reg pass requires TargetData which does not
seem to be available. The only reason why it requires it, is to pass to
lib/Transforms/Utils/PromoteMemoryToRegister.cpp:isAllocaPromotable, which
does not use that data at all.
> in the implementation of some analysis, I need to change the program and
> then invoke Mem2Reg pass. That pass, in turn, requires other analysis, so
> I must
Usually you want to do this at a higher level, why not just use 'opt
-yourpass -mem2reg'?
Because my pass must first modify the code, then run mem2reg pass and then do
some more work. There's absolutely no way it could work without mem2reg pass.
(That's the value analysis path I talked about earlier).
Alternatively, if you don't want to do that, you can build mem2reg into
your pass if it works better. To do this, your pass needs to
'addRequired' DominatorTree and DominatorFrontier, then use the
interfaces exposed through
include/llvm/Transforms/Utils/PromoteMemToReg.h.
This still leaves the question of TargetData parameter -- which is not used by
the PromoteMemToReg function, AFAICT. Passing *(TargetData*)0 is dirty.
> > in the implementation of some analysis, I need to change the program and
> > then invoke Mem2Reg pass. That pass, in turn, requires other analysis, so
> > I must
>
> Usually you want to do this at a higher level, why not just use 'opt
> -yourpass -mem2reg'?
Because my pass must first modify the code, then run mem2reg pass and then do
some more work. There's absolutely no way it could work without mem2reg pass.
(That's the value analysis path I talked about earlier).
ok
> Alternatively, if you don't want to do that, you can build mem2reg into
> your pass if it works better. To do this, your pass needs to
> 'addRequired' DominatorTree and DominatorFrontier, then use the
> interfaces exposed through
> include/llvm/Transforms/Utils/PromoteMemToReg.h.
This still leaves the question of TargetData parameter -- which is not used by
the PromoteMemToReg function, AFAICT. Passing *(TargetData*)0 is dirty.
Just addRequired<TargetData>(), and pass in getAnalysis<TargetData>() as
appropriate.
This did not work for me -- it seems the "analyze" program does not provide
any TargetData. Probably, analysis pass which modifies program is not
typical, but then it's surely not transformation pass, either.
This is weird but I tried again and again and the tools are working fine now.
I was working in school account, maybe some change in permissions worked.
Otherwise I am confused.