[llvm-commits] [llvm] r128782 - in /llvm/trunk: include/llvm/Transforms/Utils/Local.h lib/Transforms/Utils/Local.cpp test/Transforms/JumpThreading/2011-04-02-SimplifyDeadBlock.ll

[Francois Pichet]

On Sun, Apr 3, 2011 at 8:43 PM, Eli Friedman <eli.friedman at gmail.com> wrote:
> On Sun, Apr 3, 2011 at 4:41 PM, Francois Pichet <pichet2000 at gmail.com> wrote:
>> On Sat, Apr 2, 2011 at 6:45 PM, Eli Friedman <eli.friedman at gmail.com> wrote:
>>> Author: efriedma
>>> Date: Sat Apr  2 17:45:17 2011
>>> New Revision: 128782
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=128782&view=rev
>>> Log:
>>> PR9446: RecursivelyDeleteTriviallyDeadInstructions can delete the instruction
>>> after the given instruction; make sure to handle that case correctly.
>>> (It's difficult to trigger; the included testcase involves a dead
>>> block, but I don't think that's a requirement.)
>>>
>>> While I'm here, get rid of the unnecessary warning about
>>> SimplifyInstructionsInBlock, since it should work correctly as far as I know.
>>>
>>>
>>> Added:
>>>    llvm/trunk/test/Transforms/JumpThreading/2011-04-02-SimplifyDeadBlock.ll
>>> Modified:
>>>    llvm/trunk/include/llvm/Transforms/Utils/Local.h
>>>    llvm/trunk/lib/Transforms/Utils/Local.cpp
>>>
>>> Modified: llvm/trunk/include/llvm/Transforms/Utils/Local.h
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/Local.h?rev=128782&r1=128781&r2=128782&view=diff
>>> ==============================================================================
>>> --- llvm/trunk/include/llvm/Transforms/Utils/Local.h (original)
>>> +++ llvm/trunk/include/llvm/Transforms/Utils/Local.h Sat Apr  2 17:45:17 2011
>>> @@ -74,10 +74,6 @@
>>>  ///
>>>  /// This returns true if it changed the code, note that it can delete
>>>  /// instructions in other blocks as well in this block.
>>> -///
>>> -/// WARNING: Do not use this function on unreachable blocks, as recursive
>>> -/// simplification is not able to handle corner-case scenarios that can
>>> -/// arise in them.
>>>  bool SimplifyInstructionsInBlock(BasicBlock *BB, const TargetData *TD = 0);
>>>
>>>  //===----------------------------------------------------------------------===//
>>>
>>> Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=128782&r1=128781&r2=128782&view=diff
>>> ==============================================================================
>>> --- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
>>> +++ llvm/trunk/lib/Transforms/Utils/Local.cpp Sat Apr  2 17:45:17 2011
>>> @@ -332,8 +332,11 @@
>>>         BI = BB->begin();
>>>       continue;
>>>     }
>>> -
>>> +
>>> +    WeakVH BIHandle(BI);
>>
>> Here BI can be equal to BB->end()
>> Hence an end iterator is dereferenced causing the crash in WeakVH
>> constructor on MSVC
>
> Ah, of course; try r128802?
>
> -Eli

Problem fixed.