Skip to content
Permalink
Browse files
8263303: C2 compilation fails with assert(found_sfpt) failed: no node…
… in loop that's not input to safepoint

Reviewed-by: roland
Backport-of: d4377af
  • Loading branch information
TheRealMDoerr committed Sep 15, 2021
1 parent 977ca31 commit 625690e44ff390924c4b9d5a028d24fb807b5eb9
Show file tree
Hide file tree
Showing 3 changed files with 75 additions and 28 deletions.
@@ -978,33 +978,6 @@ void LoopNode::verify_strip_mined(int expect_skeleton) const {
Node* sfpt = outer_le->in(0);
assert(sfpt->Opcode() == Op_SafePoint, "where's the safepoint?");
Node* inner_out = sfpt->in(0);
if (inner_out->outcnt() != 1) {
ResourceMark rm;
Unique_Node_List wq;

for (DUIterator_Fast imax, i = inner_out->fast_outs(imax); i < imax; i++) {
Node* u = inner_out->fast_out(i);
if (u == sfpt) {
continue;
}
wq.clear();
wq.push(u);
bool found_sfpt = false;
for (uint next = 0; next < wq.size() && !found_sfpt; next++) {
Node *n = wq.at(next);
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax && !found_sfpt; i++) {
Node* u = n->fast_out(i);
if (u == sfpt) {
found_sfpt = true;
}
if (!u->is_CFG()) {
wq.push(u);
}
}
}
assert(found_sfpt, "no node in loop that's not input to safepoint");
}
}
CountedLoopEndNode* cle = inner_out->in(0)->as_CountedLoopEnd();
assert(cle == inner->loopexit_or_null(), "mismatch");
bool has_skeleton = outer_le->in(1)->bottom_type()->singleton() && outer_le->in(1)->bottom_type()->is_int()->get_con() == 0;
@@ -1851,7 +1851,7 @@ static void clone_outer_loop_helper(Node* n, const IdealLoopTree *loop, const Id
Node* u = n->fast_out(j);
assert(check_old_new || old_new[u->_idx] == NULL, "shouldn't have been cloned");
if (!u->is_CFG() && (!check_old_new || old_new[u->_idx] == NULL)) {
Node* c = phase->get_ctrl(u);
Node* c = u->in(0) != NULL ? u->in(0) : phase->get_ctrl(u);
IdealLoopTree* u_loop = phase->get_loop(c);
assert(!loop->is_member(u_loop), "can be in outer loop or out of both loops only");
if (outer_loop->is_member(u_loop)) {
@@ -1974,11 +1974,20 @@ void PhaseIdealLoop::clone_outer_loop(LoopNode* head, CloneLoopMode mode, IdealL
Node* old = extra_data_nodes.at(i);
clone_outer_loop_helper(old, loop, outer_loop, old_new, wq, this, true);
}

Node* inner_out = sfpt->in(0);
if (inner_out->outcnt() > 1) {
clone_outer_loop_helper(inner_out, loop, outer_loop, old_new, wq, this, true);
}

Node* new_ctrl = cl->outer_loop_exit();
assert(get_loop(new_ctrl) != outer_loop, "must be out of the loop nest");
for (uint i = 0; i < wq.size(); i++) {
Node* n = wq.at(i);
set_ctrl(n, new_ctrl);
if (n->in(0) != NULL) {
_igvn.replace_input_of(n, 0, new_ctrl);
}
clone_outer_loop_helper(n, loop, outer_loop, old_new, wq, this, false);
}
} else {
@@ -0,0 +1,65 @@
/*
* Copyright (c) 2021, Red Hat, Inc. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/

/**
* @test
* @bug 8263303
* @summary C2 compilation fails with assert(found_sfpt) failed: no node in loop that's not input to safepoint
*
* @run main/othervm -XX:-BackgroundCompilation -XX:LoopUnrollLimit=0 TestPinnedUseInOuterLSMUnusedBySfpt
*
*/

public class TestPinnedUseInOuterLSMUnusedBySfpt {
public static void main(String[] args) {
int[] array = new int[10000];
for (int i = 0; i < 20_000; i++) {
test(100, array, 42);
test(100, array, 0);
}
}

private static float test(int stop, int[] array, int val) {
if (array == null) {
}
int j;
for (j = 0; j < 10; j++) {

}
int i;
int v = 0;
float f = 1;
for (i = 0; i < 10000; i++) {
if ((j - 10) * i + val == 42) {
f *= 2;
} else {
f *= 3;
}
v = (j - 10) * array[i];
if (i % 10001 != i) {
return v;
}
}
return v + array[i-1] + f;
}
}

1 comment on commit 625690e

@openjdk-notifier
Copy link

@openjdk-notifier openjdk-notifier bot commented on 625690e Sep 15, 2021

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Please sign in to comment.