https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127485
Bug ID: 127485
Summary: VRP misses that if the difference between two values
is non-zero then the two values are different
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Created attachment 65634
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=65634&action=edit
testcase
With the testcase, since the range of diff does not include 0, then we know
that x cannot be the same as y. This is true for both wrapping and overflow
being undefined case.
I think this might be fixed by
https://gcc.gnu.org/pipermail/gcc-patches/2026-September/730734.html or maybe a
follow up.
Note I am filing this more because of the LLVM issue
(https://github.com/llvm/llvm-project/issues/223345) that was filed.
