Hi, Is there any API within llvm that provides methods to access the CFG and do some manipulations on the CFG. Thanks, Rohith. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20100317/5536c443/attachment.html>
Hi Rohith,> Is there any API within llvm that provides methods to access the CFG > and do some manipulations on the CFG.the CFG is built into the LLVM IR: given a basic block (i.e. a node of the CFG) you can iterate over its successors and predecessors using the methods in include/llvm/Support/CFG.h. To modify the CFG you have to modify the basic blocks, usually by changing the basic block terminator. Ciao, Duncan.
Hi Rohith,> I'm actually working on building a dependence graph . I'm not able > to find the methods which llvm uses to build the CFG. Is it possible to > use the same functions do build a dependence graph ( i Know the CFG > nodes are basicblocks where as dependence graph nodes will be variables)?.LLVM does not have explicit methods to build the CFG because it is created automatically when you build the IR. For example, each basic block must finish with a "terminator" instruction (branch, return, invoke, etc). Each terminator instruction specifies which other basic blocks control can reach. Thus to find the successor nodes of a basic block, you look at the last instruction of the basic block, and see where it says control flows to. There are of course helper methods that do this for you. Predecessors are also automatically set up. Similarly, the list of uses of "variables" (aka instructions) is maintained automatically. Ciao, Duncan. PS: Please reply to the list rather than me personally. I've CC'd the list.> > Thanks, > Rohith. > > On Thu, Mar 18, 2010 at 4:55 PM, Rohith Goparaju <rgoparaj at umail.iu.edu > <mailto:rgoparaj at umail.iu.edu>> wrote: > > Thanks Duncan...That was helpful. > > > On Thu, Mar 18, 2010 at 4:54 AM, Duncan Sands <baldrick at free.fr > <mailto:baldrick at free.fr>> wrote: > > Hi Rohith, > > > Is there any API within llvm that provides methods to > access the CFG > > and do some manipulations on the CFG. > > the CFG is built into the LLVM IR: given a basic block (i.e. a > node of the > CFG) you can iterate over its successors and predecessors using > the methods > in include/llvm/Support/CFG.h. To modify the CFG you have to > modify the > basic blocks, usually by changing the basic block terminator. > > Ciao, > > Duncan. > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu <mailto:LLVMdev at cs.uiuc.edu> > http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > >
Hi Duncan,
Does llvm have any specific methods to build dependenece graphs ?
Thanks,
Rohith.
On Fri, Mar 26, 2010 at 4:50 AM, Duncan Sands <baldrick at free.fr> wrote:
> Hi Rohith,
>
>
> I'm actually working on building a dependence graph . I'm not
able
>> to find the methods which llvm uses to build the CFG. Is it possible to
>> use the same functions do build a dependence graph ( i Know the CFG
>> nodes are basicblocks where as dependence graph nodes will be
variables)?.
>>
>
> LLVM does not have explicit methods to build the CFG because it is created
> automatically when you build the IR. For example, each basic block must
> finish with a "terminator" instruction (branch, return, invoke,
etc). Each
> terminator instruction specifies which other basic blocks control can
> reach.
> Thus to find the successor nodes of a basic block, you look at the last
> instruction of the basic block, and see where it says control flows to.
> There are of course helper methods that do this for you. Predecessors are
> also automatically set up.
>
> Similarly, the list of uses of "variables" (aka instructions) is
maintained
> automatically.
>
> Ciao,
>
> Duncan.
>
> PS: Please reply to the list rather than me personally. I've CC'd
the
> list.
>
>
>> Thanks,
>> Rohith.
>>
>> On Thu, Mar 18, 2010 at 4:55 PM, Rohith Goparaju <rgoparaj at
umail.iu.edu
>> <mailto:rgoparaj at umail.iu.edu>> wrote:
>>
>> Thanks Duncan...That was helpful.
>>
>>
>> On Thu, Mar 18, 2010 at 4:54 AM, Duncan Sands <baldrick at
free.fr
>> <mailto:baldrick at free.fr>> wrote:
>>
>> Hi Rohith,
>>
>> > Is there any API within llvm that provides methods to
>> access the CFG
>> > and do some manipulations on the CFG.
>>
>> the CFG is built into the LLVM IR: given a basic block (i.e. a
>> node of the
>> CFG) you can iterate over its successors and predecessors using
>> the methods
>> in include/llvm/Support/CFG.h. To modify the CFG you have to
>> modify the
>> basic blocks, usually by changing the basic block terminator.
>>
>> Ciao,
>>
>> Duncan.
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu <mailto:LLVMdev at cs.uiuc.edu>
>>
>> http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>>
>>
>>
>
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