[Bug c/112559] New: The -fno-builtin option affects the instruction generation of the program

[Bug c/112559] New: The -fno-builtin option affects the instruction generation of the program

[mumuxi_ll at outlook dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112559

            Bug ID: 112559
           Summary: The -fno-builtin option affects the instruction
                    generation of the program
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mumuxi_ll at outlook dot com
  Target Milestone: ---

Created attachment 56600
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56600&action=edit
C source code

Upon compiling a function, it was observed that adding the -fno-builtin option
resulted in the compilation of line 2795, where the set_head_size function in
the mEMALIGn function occurs. Without the -fno-builtin option, the
set_head_size does not appear in the assembly code. Does the gcc behavior
change when processing -fno-builtin?

[Bug c/112559] The -fno-builtin option affects the instruction generation of the program

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112559

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |INVALID
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
>Does the gcc behavior change when processing -fno-builtin?

Yes because we gcc understands the behavior of free, malloc, realloc, etc.
In your case since you are implementing those functions -fno-builtin is
required.