[LLVMdev] Specify dominator for BasicBlock to avoid "Instruction does not dominate all uses!"

[ether zhhb]

hi,

you may also add something like this in the "getAnalysisUsage" of your pass:

  AU.addRequiredID(DemoteRegisterToMemoryID);

After this, the reg2mem pass will always run before your pass.

best regards
ether

On Tue, Oct 12, 2010 at 8:24 PM, Xinfinity <xinfinity_a at yahoo.com> wrote:
>
> Hi, I tried adding the PHI nodes in BB_unique, and it works for the simple
> case described here, but in case the nodes were declared in some
> predecessors of ExitBB1 and used in ExitBB1_redirect and its successors, it
> won't work, unless I create entries for all of them in BB_unique.
>
> B1 (declares PHI_1)                        B3
>  |                                                     |
> B2                                                   |
> |                                                      |
> ExitBB1                                        ExitBB2
>  |
> Succ1 (uses PHI_1)
>
> becomes:
>
> B1 (declares PHI_1)                        B3
>  |                                                     |
> B2                                                   |
> |                                                      |
> ExitBB1                                        ExitBB2
>  |                                                    |
>  -------------------------------------------------------
>                           |
>                  BB_unique
>                   /            \
>  ExitBB1_redirect     ExitBB2_redirect
>             |
> Succ1 (uses PHI_1)
>
>
>
>
>
> Devang Patel wrote:
>>
>>
>>
>> One approach is to use insert PHI nodes in BB_unique for values defined in
>> ExitBB1 and use these phi nodes in ExitBB1_redirect.
>>
>>
>>
>> Devang
>>
>>
>>
>
> I will use the pass -reg2mem, as suggested by ether, to avoid to PHI nodes
> altogether.
>
> Thanks,
> Alexandra
> -
>
> --
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