[Bug middle-end/67797] builtin functions should be able to know when their first argument is returned

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67797

Andrew Pinski  changed:

   What|Removed |Added

 CC||jakub at gcc dot gnu.org

--- Comment #3 from Andrew Pinski  ---
*** Bug 92867 has been marked as a duplicate of this bug. ***

[Bug middle-end/67797] builtin functions should be able to know when their first argument is returned

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67797

--- Comment #2 from Marc Glisse  ---
Note that gcc knows about it, thanks to the "fn spec" attribute (see also
ERF_RETURNS_ARG), it just doesn't try hard enough to take advantage of it.

[Bug middle-end/67797] builtin functions should be able to know when their first argument is returned

[rearnsha at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67797

Richard Earnshaw  changed:

   What|Removed |Added

   Priority|P3  |P4
 Status|UNCONFIRMED |NEW
   Keywords||missed-optimization
   Last reconfirmed||2015-12-23
  Component|target  |middle-end
 Ever confirmed|0   |1
Summary|[ARM] Unnecessary r0 saving |builtin functions should be
   |for memset call |able to know when their
   ||first argument is returned
   Severity|normal  |enhancement

--- Comment #1 from Richard Earnshaw  ---
This isn't target specific.  GCC does not currently realise that many string
functions return their first argument as a result.