[LLVMdev] Boostrap Failure -- Expected Differences?

[David Greene]

Evan Cheng wrote:

> These are nasty to track down. Can you pick a .c file that's  
> miscomparing and verify with stage2 and stage3 cc1 do produce  
> different .s files? If so, you need to track down which of the .o  
> files that are being linked to create the stage3 cc1 is miscompiled  
> (by replacing them with known good .o files one by one). Once you  
> have narrowed it down to a single file, compile it with stage1 and  
> stage2 cc1 to get the different .s files. Hopefully it's possible to  
> spot the bug then.
> 
> Sorry if  it sounds like as much fun as a root canal. But these  
> usually require some brute force efforts to track down.

Yep, been there, done that, wrote a script in graduate school.  Am
now resurrecting said script and will hopefully be contributing it
back to the community ASAP.

Fun times.  :)

                            -Dave