[LLVMdev] MCJIT

[Jim Grosbach]

On May 14, 2012, at 10:21 AM, Ashok Nalkund <ashoknn at qualcomm.com> wrote:

> On 5/14/2012 9:51 AM, Jim Grosbach wrote:
>> 
>>>> 
>>>> If you're hitting that code, you're running the old JIT (which does indeed not support inline assembly), not the MCJIT.
>>>> 
>>> 
>>> Do I need to enable anything at configure, my configure looks like this:
>>>> ../llvm/configure --enable-libffi --enable-targets=host-only --prefix=/local/mnt/workspace/ashoknn/crd/neo/llvm/proto/llvmsvn/build/bin
>>> 
>>> I added the enable-libffi when trying to figure out resolving external libs.
>>> 
>> 
>> 
>> No, selecting MCJIT vs. the old JIT is done in the EngineBuilder. If you're using lli, you can pass -use-mcjit on the command line. If you're using your own driver, you can use the lli.cpp for a reference.
>> 
>> -Jim
> 
> Thats what I was pointed to earlier, and following that I set the flag in EngineBuilder.setUseMCJIT(true). I looked at the code of EngineBuilder, it saves the flag but the flag doesnt seem to be used anywhere. Am I missing something?

Hm. OK, that's odd. It should change which constructor gets called in EngineBuilder::create()  (which is in lib/ExecutionEngine/ExecutionEngine.cpp). Are you perhaps calling setUseMCJIT(true) after having already called create()? Can you step through EngineBuilder::create() and see what's happening there?

-Jim