8048170: Test closed/java/text/Normalizer/ConformanceTest.java failed
Summary: PhaseIdealLoop::split_if_with_blocks_post() shoulnd't reorder range checks adjusted by range check smearing
Reviewed-by: kvn, jrose
--- a/hotspot/src/share/vm/opto/loopopts.cpp Mon Dec 01 11:59:56 2014 +0100
+++ b/hotspot/src/share/vm/opto/loopopts.cpp Thu Dec 04 14:34:11 2014 +0100
@@ -241,8 +241,13 @@
ProjNode* dp_proj = dp->as_Proj();
ProjNode* unc_proj = iff->as_If()->proj_out(1 - dp_proj->_con)->as_Proj();
if (exclude_loop_predicate &&
- unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_predicate))
+ (unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_predicate) ||
+ unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_range_check))) {
+ // If this is a range check (IfNode::is_range_check), do not
+ // reorder because Compile::allow_range_check_smearing might have
+ // changed the check.
return; // Let IGVN transformation change control dependence.
+ }
IdealLoopTree *old_loop = get_loop(dp);
@@ -898,23 +903,23 @@
int n_op = n->Opcode();
// Check for an IF being dominated by another IF same test
- if( n_op == Op_If ) {
+ if (n_op == Op_If) {
Node *bol = n->in(1);
uint max = bol->outcnt();
// Check for same test used more than once?
- if( n_op == Op_If && max > 1 && bol->is_Bool() ) {
+ if (max > 1 && bol->is_Bool()) {
// Search up IDOMs to see if this IF is dominated.
Node *cutoff = get_ctrl(bol);
// Now search up IDOMs till cutoff, looking for a dominating test
Node *prevdom = n;
Node *dom = idom(prevdom);
- while( dom != cutoff ) {
- if( dom->req() > 1 && dom->in(1) == bol && prevdom->in(0) == dom ) {
+ while (dom != cutoff) {
+ if (dom->req() > 1 && dom->in(1) == bol && prevdom->in(0) == dom) {
// Replace the dominated test with an obvious true or false.
// Place it on the IGVN worklist for later cleanup.
C->set_major_progress();
- dominated_by( prevdom, n, false, true );
+ dominated_by(prevdom, n, false, true);
#ifndef PRODUCT
if( VerifyLoopOptimizations ) verify();
#endif
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/rangechecks/TestRangeCheckSmearingLoopOpts.java Thu Dec 04 14:34:11 2014 +0100
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. 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 8048170
+ * @summary Following range check smearing, range check cannot be replaced by dominating identical test.
+ * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement TestRangeCheckSmearingLoopOpts
+ *
+ */
+public class TestRangeCheckSmearingLoopOpts {
+
+ static int dummy;
+
+ static int m1(int[] array, int i) {
+ for (;;) {
+ for (;;) {
+ if (array[i] < 0) { // range check (i+0) dominates equivalent check below
+ break;
+ }
+ i++;
+ }
+
+ // A control flow that stops IfNode::up_one_dom()
+ if ((i % 2)== 0) {
+ if ((array[i] % 2) == 0) {
+ dummy = i;
+ }
+ }
+
+ // IfNode::Ideal will rewrite some range checks if Compile::allow_range_check_smearing
+ if (array[i-1] == 9) { // range check (i-1) unchanged
+ int res = array[i-3]; // range check (i-3) unchanged
+ res += array[i]; // range check (i+0) unchanged
+ res += array[i-2]; // removed redundant range check
+ // the previous access might be hoisted by
+ // PhaseIdealLoop::split_if_with_blocks_post because
+ // it appears to have the same guard, but it also
+ // depends on the previous guards
+ return res;
+ }
+ i++;
+ }
+ }
+
+ static public void main(String[] args) {
+ int[] array = { 0, 1, 2, -3, 4, 5, -2, 7, 8, 9, -1 };
+ for (int i = 0; i < 20000; i++) {
+ m1(array, 0);
+ }
+ array[0] = -1;
+ try {
+ m1(array, 0);
+ } catch(ArrayIndexOutOfBoundsException aioobe) {}
+ }
+}