[Bug tree-optimization/104356] New: [12 Regression] divide by zero trap is being removed now when it should not be in some cases

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104356

            Bug ID: 104356
           Summary: [12 Regression] divide by zero trap is being removed
                    now when it should not be in some cases
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Created attachment 52335
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52335&action=edit
gnat.dg/div_zero.adb

>From https://gcc.gnu.org/pipermail/gcc-patches/2022-January/589490.html

Right, for example in Ada where we now happily turn a division by zero, which 
should raise an exception with -gnatp, into nonsense.  Do we really need this 
rather useless optimization in GCC?  Blindly mimicing LLVM is not a reason...

I have installed the attached testcase, which now fails because of the change.

        * gnat.dg/div_zero.adb: New test.