https://bugs.llvm.org/show_bug.cgi?id=51471
Bug ID: 51471
Summary: LICM incorrect load/store promotion in presence of
poison
Product: libraries
Version: trunk
Hardware: All
OS: All
Status: NEW
Severity: normal
Priority: P
Component: Loop Optimizer
Assignee: unassignedb...@nondot.org
Reporter: d.malju...@yandex.ru
CC: llvm-bugs@lists.llvm.org
Created attachment 25131
--> https://bugs.llvm.org/attachment.cgi?id=25131&action=edit
reproducer, run with opt -licm
If there are two groups of memory accesses in the loop all to the same memory
but one is done via "poisoned" pointer, basic-aa can just place them into two
non-aliasing sets. LICM would then promote both of these groups leading to a
miscompile: https://llvm.godbolt.org/z/KKxdb5e9v
The load/store with a poison pointer is a dead code and would never execute at
runtime.
Similar IR was produced on an actual example after value propagation through a
switch case.
--
You are receiving this mail because:
You are on the CC list for the bug._______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
