8231550: C2: ShouldNotReachHere() in verify_strip_mined_scheduling
Reviewed-by: vlivanov, thartmann
--- a/src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp Tue Oct 01 10:28:12 2019 +0200
+++ b/src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp Wed Oct 02 17:32:08 2019 +0200
@@ -1276,12 +1276,32 @@
// The rethrow call may have too many projections to be
// properly handled here. Given there's no reason for a
// barrier to depend on the call, move it above the call
- if (phase->get_ctrl(val) == ctrl) {
- assert(val->Opcode() == Op_DecodeN, "unexpected node");
- assert(phase->is_dominator(phase->get_ctrl(val->in(1)), call->in(0)), "Load is too low");
- phase->set_ctrl(val, call->in(0));
- }
- phase->set_ctrl(lrb, call->in(0));
+ stack.push(lrb, 0);
+ do {
+ Node* n = stack.node();
+ uint idx = stack.index();
+ if (idx < n->req()) {
+ Node* in = n->in(idx);
+ stack.set_index(idx+1);
+ if (in != NULL) {
+ if (phase->has_ctrl(in)) {
+ if (phase->is_dominator(call, phase->get_ctrl(in))) {
+#ifdef ASSERT
+ for (uint i = 0; i < stack.size(); i++) {
+ assert(stack.node_at(i) != in, "node shouldn't have been seen yet");
+ }
+#endif
+ stack.push(in, 0);
+ }
+ } else {
+ assert(phase->is_dominator(in, call->in(0)), "no dependency on the call");
+ }
+ }
+ } else {
+ phase->set_ctrl(n, call->in(0));
+ stack.pop();
+ }
+ } while(stack.size() > 0);
continue;
}
CallProjections projs;
--- a/src/hotspot/share/opto/loopnode.cpp Tue Oct 01 10:28:12 2019 +0200
+++ b/src/hotspot/share/opto/loopnode.cpp Wed Oct 02 17:32:08 2019 +0200
@@ -4049,28 +4049,32 @@
// dominated by early is considered a potentially interfering store.
// This can produce false positives.
if (n->is_Load() && LCA != early) {
- Node_List worklist;
-
- Node *mem = n->in(MemNode::Memory);
- for (DUIterator_Fast imax, i = mem->fast_outs(imax); i < imax; i++) {
- Node* s = mem->fast_out(i);
- worklist.push(s);
- }
- while(worklist.size() != 0 && LCA != early) {
- Node* s = worklist.pop();
- if (s->is_Load() || s->Opcode() == Op_SafePoint ||
- (s->is_CallStaticJava() && s->as_CallStaticJava()->uncommon_trap_request() != 0)) {
- continue;
- } else if (s->is_MergeMem()) {
- for (DUIterator_Fast imax, i = s->fast_outs(imax); i < imax; i++) {
- Node* s1 = s->fast_out(i);
- worklist.push(s1);
- }
- } else {
- Node *sctrl = has_ctrl(s) ? get_ctrl(s) : s->in(0);
- assert(sctrl != NULL || s->outcnt() == 0, "must have control");
- if (sctrl != NULL && !sctrl->is_top() && is_dominator(early, sctrl)) {
- LCA = dom_lca_for_get_late_ctrl(LCA, sctrl, n);
+ int load_alias_idx = C->get_alias_index(n->adr_type());
+ if (C->alias_type(load_alias_idx)->is_rewritable()) {
+
+ Node_List worklist;
+
+ Node *mem = n->in(MemNode::Memory);
+ for (DUIterator_Fast imax, i = mem->fast_outs(imax); i < imax; i++) {
+ Node* s = mem->fast_out(i);
+ worklist.push(s);
+ }
+ while(worklist.size() != 0 && LCA != early) {
+ Node* s = worklist.pop();
+ if (s->is_Load() || s->Opcode() == Op_SafePoint ||
+ (s->is_CallStaticJava() && s->as_CallStaticJava()->uncommon_trap_request() != 0)) {
+ continue;
+ } else if (s->is_MergeMem()) {
+ for (DUIterator_Fast imax, i = s->fast_outs(imax); i < imax; i++) {
+ Node* s1 = s->fast_out(i);
+ worklist.push(s1);
+ }
+ } else {
+ Node *sctrl = has_ctrl(s) ? get_ctrl(s) : s->in(0);
+ assert(sctrl != NULL || s->outcnt() == 0, "must have control");
+ if (sctrl != NULL && !sctrl->is_top() && C->can_alias(s->adr_type(), load_alias_idx) && is_dominator(early, sctrl)) {
+ LCA = dom_lca_for_get_late_ctrl(LCA, sctrl, n);
+ }
}
}
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/compiler/loopstripmining/TestConservativeAntiDep.java Wed Oct 02 17:32:08 2019 +0200
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2019, 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 8231550
+ * @summary C2: ShouldNotReachHere() in verify_strip_mined_scheduling
+ *
+ * @run main/othervm -XX:-BackgroundCompilation -XX:LoopMaxUnroll=0 TestConservativeAntiDep
+ *
+ */
+
+import java.lang.reflect.Array;
+import java.util.Arrays;
+
+public class TestConservativeAntiDep {
+ private static long longField;
+
+ public static void main(String[] args) throws InstantiationException, IllegalAccessException {
+ for (int i = 0; i < 20_000; i++) {
+ test1(A.class);
+ test2(B.class);
+ }
+ }
+
+ private static int test1(Class klass) {
+ Object[] in = (Object[])Array.newInstance(klass, 100);
+
+ Object[] o = in;
+ int v = 1;
+ // CountedLoop has control dependent CastPP
+ for (int i = 0; i < 100 ; i++) {
+ longField = i; // sunk in outer strip mined loop
+ o = (A[]) o;
+ v *= 2;
+ }
+
+ // LoadRange cannot float higher than CountedLoop (because of
+ // CastPP) and is found anti-dependent with long store so
+ // scheduled in outer strip mined loop
+ return v + o.length;
+ }
+
+ private static int test2(Class klass) throws IllegalAccessException, InstantiationException {
+ A in = (A)klass.newInstance();
+
+ A o = in;
+ int v = 1;
+ // CountedLoop has control dependent CastPP
+ for (int i = 0; i < 100 ; i++) {
+ longField = i; // sunk in outer strip mined loop
+ o = (B) o;
+ v *= 2;
+ }
+
+ // Load cannot float higher than CountedLoop (because of
+ // CastPP) and is found anti-dependent with long store so
+ // scheduled in outer strip mined loop
+ return v + o.intField;
+ }
+
+ private static class A {
+ int intField;
+ public A() {}
+ }
+
+ private static class B extends A {
+ public B() {}
+ }
+}