[llvm-commits] [llvm] r72364 - in /llvm/trunk: include/llvm/Analysis/ScalarEvolutionExpander.h lib/Analysis/ScalarEvolutionExpander.cpp lib/Transforms/Scalar/IndVarSimplify.cpp test/Transforms/IndVarSimplify/2009-05-24-useafterfree.ll

[Dan Gohman]

On May 24, 2009, at 12:41 PM, Török Edwin wrote:

> On 2009-05-24 22:05, Török Edwin wrote:
>>
>>
>> Maybe instead of AssertingVH we could use CallbackVH, and have it  
>> assert
>> only if you
>> want to dereference a deleted Value*. Does that sound reasonable?
>>
>
> Actually I think the Rewriter.clear() could be moved before those  
> last 2
> functions that use the Rewriter.
> FixUsesBeforeDefs and SinkUnusedInvariants only need  
> isInsertedInstruction.
> That one is uses the InsertedValues set which doesn't use AssertingVH,
> it is also not cleared by Rewriter.clear().
>
> In fact only RewriteIVExpressions needs isInsertedExpression, so I  
> think
> it would be safe to clear the Rewriter map right after calling
> RewriteIVExpressions.

Ok, this sounds reasonable.  I'm concerned about the
RecursivelyDeleteTriviallyDeadInstructions call at the end of
RewriteIVExpressions, but this can be covered by making the
clear() happen even earlier.

Thanks,

Dan