Hi All, Still I could not figure out how to use Pass* while calling SplitEdge() function. Can anyone provide me some example? Regards, Chayan On Sun, Jul 18, 2010 at 11:49 PM, Nick Lewycky <nicholas at mxc.ca> wrote:> Chayan Sarkar wrote: >> >> Hi, >> >> I have tried to use SplitEdge function, but failed. Actually the third >> parameter is a variable of type Pass and it need to be non-null. But I >> could not figure out how to use it. Please help me out. > > The only reason it needs a non-NULL Pass* is to call llvm::SplitBlock which > uses P->getAnalysisIfAvailable unconditionally. Feel free to wrap those > calls in 'if (P) { ... }' and send us a patch. > > Of course, the obvious question is why aren't you doing your transforms > inside of a Pass? > > Nick > >> Regards, >> Chayan >> >> On Sat, Jul 17, 2010 at 10:16 PM, Nick Lewycky<nicholas at mxc.ca> wrote: >>> >>> Chayan Sarkar wrote: >>>> >>>> Hi all, >>>> >>>> Suppose in a CFG bb1 has two succesor bb3 and bb4, and bb3 has two >>>> predecessor bb1 and bb2. Now how can I insert a basic block between >>>> bb1 and bb3 that at the edge bb1-->bb3 . >>>> >>>> In general how can I insert a basic block on an edge? >>> >>> Use llvm::SplitEdge in Transforms/Utils/BasicBlockUtils.h. >>> >>> The technique is to create a new bb with a single branch to bb3, then >>> modify >>> bb1's use of bb3 to point to 'new bb' instead, then fix up any phi nodes >>> in >>> bb3 by replacing uses of bb1 with 'new bb'. >>> >>> Nick >>> >> > >
Hi, I could not figure out, how to declare a Pass*. Can anyone give me an example, how to use SplitEdge() function ? Please help me out. Regards, Chayan On Tue, Jul 20, 2010 at 10:12 AM, Chayan Sarkar <chayan.ju at gmail.com> wrote:> Hi All, > > Still I could not figure out how to use Pass* while calling > SplitEdge() function. Can anyone provide me some example? > > Regards, > Chayan > > On Sun, Jul 18, 2010 at 11:49 PM, Nick Lewycky <nicholas at mxc.ca> wrote: >> Chayan Sarkar wrote: >>> >>> Hi, >>> >>> I have tried to use SplitEdge function, but failed. Actually the third >>> parameter is a variable of type Pass and it need to be non-null. But I >>> could not figure out how to use it. Please help me out. >> >> The only reason it needs a non-NULL Pass* is to call llvm::SplitBlock which >> uses P->getAnalysisIfAvailable unconditionally. Feel free to wrap those >> calls in 'if (P) { ... }' and send us a patch. >> >> Of course, the obvious question is why aren't you doing your transforms >> inside of a Pass? >> >> Nick >> >>> Regards, >>> Chayan >>> >>> On Sat, Jul 17, 2010 at 10:16 PM, Nick Lewycky<nicholas at mxc.ca> wrote: >>>> >>>> Chayan Sarkar wrote: >>>>> >>>>> Hi all, >>>>> >>>>> Suppose in a CFG bb1 has two succesor bb3 and bb4, and bb3 has two >>>>> predecessor bb1 and bb2. Now how can I insert a basic block between >>>>> bb1 and bb3 that at the edge bb1-->bb3 . >>>>> >>>>> In general how can I insert a basic block on an edge? >>>> >>>> Use llvm::SplitEdge in Transforms/Utils/BasicBlockUtils.h. >>>> >>>> The technique is to create a new bb with a single branch to bb3, then >>>> modify >>>> bb1's use of bb3 to point to 'new bb' instead, then fix up any phi nodes >>>> in >>>> bb3 by replacing uses of bb1 with 'new bb'. >>>> >>>> Nick >>>> >>> >> >> >
See http://llvm.org/docs/WritingAnLLVMPass.html
If you are inside MyPass::runOn{Module,Function,Loop,BasicBlock}(),
just use the "this" pointer.
Olivier
On Wed, Jul 21, 2010 at 7:35 PM, Chayan Sarkar <chayan.ju at gmail.com>
wrote:> Hi,
>
> I could not figure out, how to declare a Pass*. Can anyone give me an
> example, how to use SplitEdge() function ?
>
> Please help me out.
>
> Regards,
> Chayan
>
> On Tue, Jul 20, 2010 at 10:12 AM, Chayan Sarkar <chayan.ju at
gmail.com> wrote:
>> Hi All,
>>
>> Still I could not figure out how to use Pass* while calling
>> SplitEdge() function. Can anyone provide me some example?
>>
>> Regards,
>> Chayan
>>
>> On Sun, Jul 18, 2010 at 11:49 PM, Nick Lewycky <nicholas at
mxc.ca> wrote:
>>> Chayan Sarkar wrote:
>>>>
>>>> Hi,
>>>>
>>>> I have tried to use SplitEdge function, but failed. Actually
the third
>>>> parameter is a variable of type Pass and it need to be
non-null. But I
>>>> could not figure out how to use it. Please help me out.
>>>
>>> The only reason it needs a non-NULL Pass* is to call
llvm::SplitBlock which
>>> uses P->getAnalysisIfAvailable unconditionally. Feel free to
wrap those
>>> calls in 'if (P) { ... }' and send us a patch.
>>>
>>> Of course, the obvious question is why aren't you doing your
transforms
>>> inside of a Pass?
>>>
>>> Nick
>>>
>>>> Regards,
>>>> Chayan
>>>>
>>>> On Sat, Jul 17, 2010 at 10:16 PM, Nick Lewycky<nicholas at
mxc.ca> wrote:
>>>>>
>>>>> Chayan Sarkar wrote:
>>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> Suppose in a CFG bb1 has two succesor bb3 and bb4, and
bb3 has two
>>>>>> predecessor bb1 and bb2. Now how can I insert a basic
block between
>>>>>> bb1 and bb3 that at the edge bb1-->bb3 .
>>>>>>
>>>>>> In general how can I insert a basic block on an edge?
>>>>>
>>>>> Use llvm::SplitEdge in Transforms/Utils/BasicBlockUtils.h.
>>>>>
>>>>> The technique is to create a new bb with a single branch to
bb3, then
>>>>> modify
>>>>> bb1's use of bb3 to point to 'new bb' instead,
then fix up any phi nodes
>>>>> in
>>>>> bb3 by replacing uses of bb1 with 'new bb'.
>>>>>
>>>>> Nick
>>>>>
>>>>
>>>
>>>
>>
>
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