[Bug rtl-optimization/114924] [11/12/13/14/15 Regression] Wrong update of MEM_EXPR by RTL loop unrolling since r11-2963-gd6a05b494b4b71

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114924

--- Comment #1 from GCC Commits  ---
The master branch has been updated by Alex Coplan :

https://gcc.gnu.org/g:fe40d525619eee9c2821126390df75068df4773a

commit r15-126-gfe40d525619eee9c2821126390df75068df4773a
Author: Alex Coplan 
Date:   Fri May 3 09:23:59 2024 +0100

cfgrtl: Fix MEM_EXPR update in duplicate_insn_chain [PR114924]

The PR shows that when cfgrtl.cc:duplicate_insn_chain attempts to
update the MR_DEPENDENCE_CLIQUE information for a MEM_EXPR we can end up
accidentally dropping (e.g.) an ARRAY_REF from the MEM_EXPR and end up
replacing it with the underlying MEM_REF.  This leads to an
inconsistency in the MEM_EXPR information, and could lead to wrong code.

While the walk down to the MEM_REF is necessary to update
MR_DEPENDENCE_CLIQUE, we should use the outer tree expression for the
MEM_EXPR.  This patch does that.

gcc/ChangeLog:

PR rtl-optimization/114924
* cfgrtl.cc (duplicate_insn_chain): When updating MEM_EXPRs,
don't strip (e.g.) ARRAY_REFs from the final MEM_EXPR.

[Bug rtl-optimization/114924] [11/12/13/14/15 Regression] Wrong update of MEM_EXPR by RTL loop unrolling since r11-2963-gd6a05b494b4b71

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114924

Richard Biener  changed:

   What|Removed |Added

   Target Milestone|--- |11.5
   Keywords||wrong-code
   Priority|P3  |P2

[Bug rtl-optimization/114924] [11/12/13/14/15 Regression] Wrong update of MEM_EXPR by RTL loop unrolling since r11-2963-gd6a05b494b4b71

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114924

Alex Coplan  changed:

   What|Removed |Added

   Assignee|unassigned at gcc dot gnu.org  |acoplan at gcc dot 
gnu.org
   Last reconfirmed||2024-05-02
 Status|UNCONFIRMED |ASSIGNED
 Ever confirmed|0   |1