[Bug rtl-optimization/64916] ira.c update_equiv_regs patch causes gcc/testsuite/gcc.target/arm/pr43920-2.c regression

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64916

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[5 regression] ira.c        |ira.c update_equiv_regs
                   |update_equiv_regs patch     |patch causes
                   |causes                      |gcc/testsuite/gcc.target/ar
                   |gcc/testsuite/gcc.target/ar |m/pr43920-2.c regression
                   |m/pr43920-2.c regression    |

--- Comment #3 from Jeffrey A. Law <law at redhat dot com> ---
Removing the regression marker.

This testcase depended in incorrect behaviour of update_equiv_regs.  So it's
clearly a missed optimization, it does not qualify as a regression IMO.

In particular note that r110 can have two values (0 or -1) thus creating a
REG_EQUIV note for r110 anywhere is wrong.