https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115298
Bug ID: 115298
Summary: [15 Regression] Various targets failing DSE tests
after recent changes
Product: gcc
Version: 15.0
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: ---
A few targets (nds32be-elf, nds32le-elf, avr-elf) have started failing a few
tests after recent aliasing changes:
Tests that now fail, but worked before (9 tests):
nds32-sim: gcc: gcc.c-torture/execute/strcpy-1.c -O3 -g (test for excess
errors)
nds32-sim: gcc: gcc.dg/tree-ssa/pr86061.c scan-tree-dump-times dse1 "Deleted
dead call" 1
nds32-sim: gcc: gcc.dg/tree-ssa/pr86061.c scan-tree-dump-times dse1 "Deleted
dead call" 1
nds32-sim: gcc: gcc.dg/tree-ssa/ssa-dse-37.c scan-tree-dump-times dse1 "Deleted
dead call" 2
nds32-sim: gcc: gcc.dg/tree-ssa/ssa-dse-37.c scan-tree-dump-times dse1 "Deleted
dead call" 2
nds32-sim: gcc: gcc.dg/tree-ssa/ssa-dse-37.c scan-tree-dump-times dse1
"Trimming statement " 4
nds32-sim: gcc: gcc.dg/tree-ssa/ssa-dse-37.c scan-tree-dump-times dse1
"Trimming statement " 4
nds32-sim: gcc: gcc.dg/tree-ssa/strncpy-1.c scan-tree-dump-not optimized
"memset"
nds32-sim: gcc: gcc.dg/tree-ssa/strncpy-1.c scan-tree-dump-not optimized
"memset"
This was bisected to:
commit c08b0d3f7b3539b26031de31d88dea6b94474577
Author: Richard Biener <rguent...@suse.de>
Date: Mon May 27 10:41:02 2024 +0200
tree-optimization/115236 - more points-to *ANYTHING = x fixes
The stored-to ANYTHING handling has more holes, uncovered by treating
volatile accesses as ANYTHING. We fail to properly build the
pred and succ graphs, in particular we may not elide direct nodes
from receiving from STOREDANYTHING.
PR tree-optimization/115236
* tree-ssa-structalias.cc (build_pred_graph): Properly
handle *ANYTHING = X.
(build_succ_graph): Likewise. Do not elide direct nodes
from receiving from STOREDANYTHING.
* gcc.dg/pr115236.c: New testcase.
I haven't done any deeper analysis.
