[llvm-commits] [llvm] r78295 - in /llvm/trunk: lib/CodeGen/SelectionDAG/DAGCombiner.cpp test/CodeGen/X86/wide-integer-fold.ll

[Dan Gohman]

On Aug 18, 2009, at 10:47 AM, Duncan Sands wrote:


> Hi Dan,
>
>
>> Fix a few places in DAGCombiner that were creating all-ones-bits
>>
>> and high-bits values in ways that weren't correct for integer
>>
>> types wider than 64 bits. This fixes a miscompile in
>>
>> PPMacroExpansion.cpp in clang on x86-64.
>>
>
> this is not a problem with your patch, but I notice that this part
> of the DAG combiner seems to make a lot of unsafe use of get?ExtValue.
> Any chance of adding this to your TODO list? :)

I scanned through all of DAGCombiner and fixed all the cases I
found where getZExtValue was used for a purpose other than a
shift count. For shift counts, values that don't fit in 64 bits
are fairly rare ;-), so it's not a high priority. If I missed
any places, I'd be happy to be shown them.

Dan