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[Bug tree-optimization/80006] loss of range information due to spurious widening conversion


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80006

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-03-13
            Summary|loss of range information   |loss of range information
                   |after widening conversion   |due to spurious widening
                   |                            |conversion
     Ever confirmed|0                           |1

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
I see.  I agree that transforming ~[-3, 7] to [SCHAR_MIN, SCHAR_MAX] when
converting a signed char to a wider type makes sense.  I was so focused on
preserving the anti-range that I hadn't thought of that.

Let me use this bug to track the spurious conversion from signed char to int
(thanks for the pointer, Joseph).  I'm not sure what Component to assign it to:
target?

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