[Bug c++/87628] Redundant check of pointer when operator delete is called

[hiraditya at msn dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87628

--- Comment #6 from AK  ---
Opened a bug for clang as well:
https://github.com/llvm/llvm-project/issues/62783

[Bug c++/87628] Redundant check of pointer when operator delete is called

[hiraditya at msn dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87628

--- Comment #5 from AK  ---
As per: https://en.cppreference.com/w/cpp/memory/new/operator_delete
"""
In all cases, if ptr is a null pointer, the standard library deallocation
functions do nothing. If the pointer passed to the standard library
deallocation function was not obtained from the corresponding standard library
allocation function, the behavior is undefined.
"""

So it should be fine to remove the check `if(p)`

[Bug c++/87628] Redundant check of pointer when operator delete is called

[hiraditya at msn dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87628

--- Comment #4 from AK  ---
Seems like clang now added the check:

$ clang++ -Oz -fno-exceptions

if_delete(char*): # @if_delete(char*)
testrdi, rdi
jne operator delete(void*)@PLT  # TAILCALL
ret

[Bug c++/87628] Redundant check of pointer when operator delete is called

[hiraditya at msn dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87628

--- Comment #3 from AK  ---
Still happening with gcc trunk.

https://godbolt.org/z/5K94665GK

[Bug c++/87628] Redundant check of pointer when operator delete is called

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87628

Eric Gallager  changed:

   What|Removed |Added

 CC||egallager at gcc dot gnu.org

--- Comment #2 from Eric Gallager  ---
(In reply to Richard Biener from comment #1)
> Confirmed.  IIRC there are duplicates of this bug.

Well related bugs for the plain-C equivalent with free() at least

[Bug c++/87628] Redundant check of pointer when operator delete is called

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87628

Richard Biener  changed:

   What|Removed |Added

   Keywords||missed-optimization
 Status|UNCONFIRMED |NEW
   Last reconfirmed||2018-10-17
 Ever confirmed|0   |1

--- Comment #1 from Richard Biener  ---
Confirmed.  IIRC there are duplicates of this bug.