llvm dev - Sep 2014 - [LLVMdev] How to cache MCJIT compiled object into memory?

Hi, All

I m not sure if this question has been asked or not. I'd like cache the
MCJIT compiled object into memory buffer so it can be reused later. I
followed the Andy Kaylor's example wrote an inherited class from
ObjectCache and use raw_fd_ostream to save the cache and load the cache
from a file. I checked raw_ostream and its subclass, maybe I am wrong but I
don't see one is fit to save to memory buffer. Any suggestions?

Thank you very much

-- 
Best regards

Cheng
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20140917/5988b479/attachment.html>

Hi Cheng,

You could use a raw_svector_ostream to write to a memory buffer, but that's
unnecessarily complicated. You just need to clone the memory buffer pointed
to by Obj. Something along the lines of:

class MyCache : public ObjectCache {
public:
  void notifyObjectCompiled(const Module *M, MemoryBufferRef Obj) override {
    CachedObjs[M]       MemoryBuffer::getMemBufferCopy(Obj.getBuffer(),
                                     Obj.getBufferIdentifier());
  }

  std::unique_ptr<MemoryBuffer> getObject(const Module *M) override {
    MemoryBuffer& B = *CachedObjs[M];
    return MemoryBuffer::getMemBufferCopy(B.getBuffer(),
B.getBufferIdentifier());
  }

private:
  std::map<Module*, std::unique_ptr<MemoryBuffer>> CachedObjs;
};


Cheers,
Lang.


On Wed, Sep 17, 2014 at 6:18 PM, Cheng Zhu <chengzhu at gmail.com> wrote:
> Hi, All
>
> I m not sure if this question has been asked or not. I'd like cache the
> MCJIT compiled object into memory buffer so it can be reused later. I
> followed the Andy Kaylor's example wrote an inherited class from
> ObjectCache and use raw_fd_ostream to save the cache and load the cache
> from a file. I checked raw_ostream and its subclass, maybe I am wrong but I
> don't see one is fit to save to memory buffer. Any suggestions?
>
> Thank you very much
>
> --
> Best regards
>
> Cheng
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20140918/598380bb/attachment.html>

Thank you Lang. That should work. I was planing to use llvm::StringRef as
the value of the CacheObjs map, and use function name string as key
earlier. I guess that should work too and less storage use right?

On Thu, Sep 18, 2014 at 10:43 AM, Lang Hames <lhames at gmail.com> wrote:
> Hi Cheng,
>
> You could use a raw_svector_ostream to write to a memory buffer, but
> that's unnecessarily complicated. You just need to clone the memory
buffer
> pointed to by Obj. Something along the lines of:
>
> class MyCache : public ObjectCache {
> public:
>   void notifyObjectCompiled(const Module *M, MemoryBufferRef Obj) override
> {
>     CachedObjs[M] >      
MemoryBuffer::getMemBufferCopy(Obj.getBuffer(),
>                                      Obj.getBufferIdentifier());
>   }
>
>   std::unique_ptr<MemoryBuffer> getObject(const Module *M) override {
>     MemoryBuffer& B = *CachedObjs[M];
>     return MemoryBuffer::getMemBufferCopy(B.getBuffer(),
> B.getBufferIdentifier());
>   }
>
> private:
>   std::map<Module*, std::unique_ptr<MemoryBuffer>> CachedObjs;
> };
>
>
> Cheers,
> Lang.
>
>
> On Wed, Sep 17, 2014 at 6:18 PM, Cheng Zhu <chengzhu at gmail.com>
wrote:
>
>> Hi, All
>>
>> I m not sure if this question has been asked or not. I'd like cache
the
>> MCJIT compiled object into memory buffer so it can be reused later. I
>> followed the Andy Kaylor's example wrote an inherited class from
>> ObjectCache and use raw_fd_ostream to save the cache and load the cache
>> from a file. I checked raw_ostream and its subclass, maybe I am wrong
but I
>> don't see one is fit to save to memory buffer. Any suggestions?
>>
>> Thank you very much
>>
>> --
>> Best regards
>>
>> Cheng
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>>
>

-- 
Best regards

Cheng
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20140918/f2d53421/attachment.html>