Re: Division by zero on A53 which does not raise an exception

[Richard Biener <richard.guenther@gmail.com>]

On Tue, Nov 29, 2022 at 5:39 AM Stephen Smith via Gcc <gcc@gcc.gnu.org> wrote:
>
> I am working on a project which is using an A53 core.   The core does not
> raise an exception if there is a division by zero (for either integer or
> floating point division).
>
> The designers chose to set status bits for the floating point case but not
> raise an exception.    With the integer division no status bits are set.
>
> Does the GCC  compilers or Binutils assembler and linker have a way to deal
> with this issue on the ARM A53 processor?
>
> For Linux, was special support added in the kernel to help Glibc with this
> issue?  If so, I will comb the linux source tree.
>
> My project is using GCC 7.3.0

I'm second-guessing that you want to have an exception raised for
integer division by zero?  Since the C standard defines this as
invoking undefined behavior and GCC generally takes advantage
of this reliably getting an exception is difficult.  There's
-fsanitize=integer-divide-by-zero -fsanitize-undefined-trap-on-error
which you could use.

There are targets with options like -mcheck-zero-division but
arm is not amongst those.

Richard.

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