https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92299
Luca Rocca <disquisitiones at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|INVALID |---
--- Comment #3 from Luca Rocca <disquisitiones at gmail dot com> ---
Division by 0 is always undefined, regardless of the numerator.
So, 0 / X should not be simplified if we cannot exclude that X = 0.
Then if X = 0 we should expect an exception triggered at runtime,
as we have for example for 1 / 0.
Consider for comparison the approach of gcc up to gcc-6.4.0,
reading this comment from the corresponding file gcc-6.4.0/gcc/match.pd:
/* Make sure to preserve divisions by zero. This is the reason why
we don't simplify x / x to 1 or 0 / x to 0. */
