llvm dev - Jan 2012 - [LLVMdev] Resolving branch instr with label "$BB0_-1"

 
Hi Aries.
Thanks very much!

Precisely this is the situation! There're two consecutive branches (br1cond
and br2uncond). Inside of AnalyzeBranch, there's an opcode swap of br2uncond
(ex. j_foward to j_backward). There I do BuildMI (newOpcode) and followed by
br2uncond->eraseFromParent(). This results in br1cond loosing it's
label/offset. How could I resolve this?

Best regards,
Girish.

May be you have branched to a BB which has been deleted.
>
>
>On 24 January 2012 20:16, girish gulawani <girishvg at yahoo.com>
wrote:
>
>
>>
>>Hello All.
>>On a particular target the back-end generates an instruction like:
>>beqz      r2, "$BB0_-1"
>>
>> 
>>Is it a back-end specific issue? Could someone please help me figure out
how this gets resolved? What confuses me is, all other branches are correctly
labelled and resolved! 
>>
>>
>>Thanks.Girish.
>>
>>
>>_______________________________________________
>>LLVM Developers mailing list
>>LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>>http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>>
>
>
>-- 
>Sincerely,
>
>Aries Wu
>
>
>
>
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> Precisely this is the situation! There're two consecutive branches
(br1cond
> and br2uncond). Inside of AnalyzeBranch, there's an opcode swap of
br2uncond
> (ex. j_foward to j_backward). There I do BuildMI (newOpcode) and followed
by
> br2uncond->eraseFromParent(). This results in br1cond loosing it's
> label/offset. How could I resolve this?
Your code is broken. AnalyzeBranch should not modify anything.

-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University

Hello Anton.
Thanks for the comment.
> Precisely this is the situation! There're two consecutive branches
(br1cond
>> and br2uncond). Inside of AnalyzeBranch, there's an opcode swap of
br2uncond
>> (ex. j_foward to j_backward). There I do BuildMI (newOpcode) and
followed by
>> br2uncond->eraseFromParent(). This results in br1cond loosing
it's
>> label/offset. How could I resolve this?
>Your code is broken. AnalyzeBranch should not modify anything.
>
>
>
>I was taking a clue from Mips/MipsInstrInfo.cpp: AnalyzeBranch :(
>Could you please suggest appropriate alternative place for such a
modification?
>Best regards,
>
>Girish.
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