[Bug tree-optimization/124175] Optimization when conditionals at the beginning of a loop may be skipped by the variables' constraints

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124175

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |alias, missed-optimization
             Status|UNCONFIRMED                 |NEW
             Blocks|                            |49774
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2026-02-20

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
The __asm__("nop") inhibits PRE.  The restrict qualification does not help
disambiguating against subroutine1() since that's not implemented in GCC.
Otherwise FSM threading would perform the optimization.

So, IMO, a dup of the restrict vs. function call bug which I think exists
somewhere ('p' is not "directly" passed to subroutine1()).


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=49774
[Bug 49774] [meta-bug] restrict qualification aliasing issues