[LLVMdev] Crash on accessing deleted MBBs (new backend)

[Chris Lattner]

On Sep 28, 2007, at 1:37 PM, Andreas Fredriksson wrote:

> Replying to my self here. It seems I was missing an isTerminator = 1
> on the branch instruction in question, so LLVM didn't know that the
> instruction terminated a basic block. Does that make sense, or is just
> masking some other problem?

Yep, that sounds right.

-Chris

> Thanks,
> Andreas
>
> On 9/28/07, Andreas Fredriksson <deplinenoise at gmail.com> wrote:
>> Hi,
>> I'm trying to write up my little m68k backend things have been going
>> smoothly. I've been working with the x86 backend as a template,  
>> fixing
>> things as I go.
>>
>> Now I've run into branches and I have a crash I don't really
>> understand. Here's the sample IR I'm running llc on to generate
>> assembly:
>> <snip>
>> llc crashes at this point because the target branch of the BLT  
>> (branch
>> if lower than) has gone away. On my win32 box it's filled with
>> 0xfeeefeee (deleted data).
>>
>> I've verified that the block is actually removed by the branch
>> folding, but for some reason this poor BLT instruction never hears
>> about that. What can I do to fix this?
>>
>> Thanks,
>> Andreas
>>
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