https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105517
Bug ID: 105517
Summary: [13 Regression] Missing diagnostic after recent
optimizer improvements
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: law at gcc dot gnu.org
Target Milestone: ---
This change:
commit ee1cb43bc76de800efa0ade687b0cd28e62a5f82
Author: Richard Biener <[email protected]>
Date: Wed Jan 26 15:34:54 2022 +0100
tree-optimization/104162 - CSE of &MEM[ptr].a[i] and ptr + CST
This adds the capability to value-numbering of treating complex
address expressions where the offset becomes invariant as equal
to a POINTER_PLUS_EXPR. This restores CSE that is now prevented
by early lowering of &MEM[ptr + CST] to a POINTER_PLUS_EXPR.
Unfortunately this regresses gcc.dg/asan/pr99673.c again, so
the testcase is adjusted accordingly.
2022-01-26 Richard Biener <[email protected]>
PR tree-optimization/104162
* tree-ssa-sccvn.cc (vn_reference_lookup): Handle
&MEM[_1 + 5].a[i] like a POINTER_PLUS_EXPR if the offset
becomes invariant.
(vn_reference_insert): Likewise.
* gcc.dg/tree-ssa/ssa-fre-99.c: New testcase.
* gcc.dg/asan/pr99673.c: Adjust.
Is causing various ports (ft32-elf for example) to fail the Warray-bounds.c
test:
Running /home/jlaw/test/gcc/gcc/testsuite/gcc.dg/dg.exp ...
FAIL: c-c++-common/Warray-bounds.c -Wc++-compat (test for warnings, line
187)
FAIL: c-c++-common/Warray-bounds.c -Wc++-compat (test for warnings, line
188)
I think you ought to be able to see this with just a cross compiler and
shouldn't need a full cross environment. I haven't debugged this in any way
other than bisection.
