Mercurial > hg > openjdk > jdk8u > hotspot
changeset 9116:5bd3b8c05552 jdk8u252-b02
8146792: Predicate moved after partial peel may lead to broken graph
Summary: partial peel can leave a pinned node between predicates and loop and prevent some loop predication
Reviewed-by: kvn, phh, andrew
| author | roland |
|---|---|
| date | Mon, 11 Jan 2016 16:02:42 +0100 |
| parents | 813683371450 |
| children | 6021152f9ff3 |
| files | src/share/vm/opto/loopPredicate.cpp test/compiler/loopopts/BadPredicateAfterPartialPeel.java |
| diffstat | 2 files changed, 337 insertions(+), 1 deletions(-) [+] |
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--- a/src/share/vm/opto/loopPredicate.cpp Wed Jan 29 07:06:55 2020 +0000 +++ b/src/share/vm/opto/loopPredicate.cpp Mon Jan 11 16:02:42 2016 +0100 @@ -502,7 +502,31 @@ _lpt(lpt), _phase(lpt->_phase), _visited(area), _invariant(area), _stack(area, 10 /* guess */), _clone_visited(area), _old_new(area) - {} + { + Node* head = _lpt->_head; + Node* entry = head->in(LoopNode::EntryControl); + if (entry->outcnt() != 1) { + // If a node is pinned between the predicates and the loop + // entry, we won't be able to move any node in the loop that + // depends on it above it in a predicate. Mark all those nodes + // as non loop invariatnt. + Unique_Node_List wq; + wq.push(entry); + for (uint next = 0; next < wq.size(); ++next) { + Node *n = wq.at(next); + for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { + Node* u = n->fast_out(i); + if (!u->is_CFG()) { + Node* c = _phase->get_ctrl(u); + if (_lpt->is_member(_phase->get_loop(c)) || _phase->is_dominator(c, head)) { + _visited.set(u->_idx); + wq.push(u); + } + } + } + } + } + } // Map old to n for invariance computation and clone void map_ctrl(Node* old, Node* n) {
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/compiler/loopopts/BadPredicateAfterPartialPeel.java Mon Jan 11 16:02:42 2016 +0100 @@ -0,0 +1,312 @@ +/* + * Copyright (c) 2016, 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 8146792 + * @summary Predicate moved after partial peel may lead to broken graph + * @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:CompileOnly=BadPredicateAfterPartialPeel::m -XX:CompileCommand=dontinline,BadPredicateAfterPartialPeel::not_inlined* -XX:CompileCommand=quiet BadPredicateAfterPartialPeel + * + */ + +public class BadPredicateAfterPartialPeel { + + static void not_inlined1() {} + static void not_inlined4() {} + + static int m_helper(int i, int i3, int i4) { + return i3 == 4 ? i4 : i; + } + + static float[] array = new float[1000]; + static int[] array2 = new int[1000]; + + boolean flag; + int j; + + static void m(BadPredicateAfterPartialPeel o1, BadPredicateAfterPartialPeel o2, BadPredicateAfterPartialPeel o, int i4) { + int i1 = 1; + + // To delay partial peeling to the loop opts pass right before CCP + int i2 = 0; + for (; i2 < 10; i2 += i1); + i2 = i2 / 10; + + // Simplified during CCP: + int i3 = 2; + for (; i3 < 4; i3 *= 2); + + // Loop is partial peeled right before CCP + int i = 0; + boolean b = true; + + not_inlined1(); + + array[0] = -1; + do { + // peeled section starts here + o.flag = false; + o.j = 0; + + if (b) { + // The following store will be pinned between + // predicates and the loop after partial peeling. All + // control flow will be optimized out and so nothing + // will prevent predicates from being moved out the + // loop. + array[i] = 0; + } + if (array[0] != 0) { + } + if (i >= 10) { + // peeled section ends here + return; + } + i += i2; + b = false; + int i5 = m_helper(i, i3, i4); // This will be simpliflied during CCP + if (array[i5] != 0) { // and this will become a predicate + } + if (o2.flag) { + } + // A bunch of stuff to grow loop body size and prevent peeling: + array2[0] = 0; + array2[1] = 0; + array2[2] = 0; + array2[3] = 0; + array2[4] = 0; + array2[5] = 0; + array2[6] = 0; + array2[7] = 0; + array2[8] = 0; + array2[9] = 0; + array2[10] = 0; + array2[11] = 0; + array2[12] = 0; + array2[13] = 0; + array2[14] = 0; + array2[15] = 0; + array2[16] = 0; + array2[17] = 0; + array2[18] = 0; + array2[19] = 0; + array2[20] = 0; + array2[21] = 0; + array2[22] = 0; + array2[23] = 0; + array2[24] = 0; + array2[25] = 0; + array2[26] = 0; + array2[27] = 0; + array2[28] = 0; + array2[29] = 0; + array2[30] = 0; + array2[31] = 0; + array2[32] = 0; + array2[33] = 0; + array2[34] = 0; + array2[35] = 0; + array2[36] = 0; + array2[37] = 0; + array2[38] = 0; + array2[39] = 0; + array2[40] = 0; + array2[41] = 0; + array2[42] = 0; + array2[43] = 0; + array2[44] = 0; + array2[45] = 0; + array2[46] = 0; + array2[47] = 0; + array2[48] = 0; + array2[49] = 0; + array2[50] = 0; + array2[51] = 0; + array2[52] = 0; + array2[53] = 0; + array2[54] = 0; + array2[55] = 0; + array2[56] = 0; + array2[57] = 0; + array2[58] = 0; + array2[59] = 0; + array2[60] = 0; + array2[61] = 0; + array2[62] = 0; + array2[63] = 0; + array2[64] = 0; + array2[65] = 0; + array2[66] = 0; + array2[67] = 0; + array2[68] = 0; + array2[69] = 0; + array2[70] = 0; + array2[71] = 0; + array2[72] = 0; + array2[73] = 0; + array2[74] = 0; + array2[75] = 0; + array2[76] = 0; + array2[77] = 0; + array2[78] = 0; + array2[79] = 0; + array2[80] = 0; + array2[81] = 0; + array2[82] = 0; + array2[83] = 0; + array2[84] = 0; + array2[85] = 0; + array2[86] = 0; + array2[87] = 0; + array2[88] = 0; + array2[89] = 0; + array2[90] = 0; + array2[91] = 0; + array2[92] = 0; + array2[93] = 0; + array2[94] = 0; + array2[95] = 0; + array2[96] = 0; + array2[97] = 0; + array2[98] = 0; + array2[99] = 0; + + array2[100] = 0; + array2[101] = 0; + array2[102] = 0; + array2[103] = 0; + array2[104] = 0; + array2[105] = 0; + array2[106] = 0; + array2[107] = 0; + array2[108] = 0; + array2[109] = 0; + array2[110] = 0; + array2[111] = 0; + array2[112] = 0; + array2[113] = 0; + array2[114] = 0; + array2[115] = 0; + array2[116] = 0; + array2[117] = 0; + array2[118] = 0; + array2[119] = 0; + array2[120] = 0; + array2[121] = 0; + array2[122] = 0; + array2[123] = 0; + array2[124] = 0; + array2[125] = 0; + array2[126] = 0; + array2[127] = 0; + array2[128] = 0; + array2[129] = 0; + array2[130] = 0; + array2[131] = 0; + array2[132] = 0; + array2[133] = 0; + array2[134] = 0; + array2[135] = 0; + array2[136] = 0; + array2[137] = 0; + array2[138] = 0; + array2[139] = 0; + array2[140] = 0; + array2[141] = 0; + array2[142] = 0; + array2[143] = 0; + array2[144] = 0; + array2[145] = 0; + array2[146] = 0; + array2[147] = 0; + array2[148] = 0; + array2[149] = 0; + array2[150] = 0; + array2[151] = 0; + array2[152] = 0; + array2[153] = 0; + array2[154] = 0; + array2[155] = 0; + array2[156] = 0; + array2[157] = 0; + array2[158] = 0; + array2[159] = 0; + array2[160] = 0; + array2[161] = 0; + array2[162] = 0; + array2[163] = 0; + array2[164] = 0; + array2[165] = 0; + array2[166] = 0; + array2[167] = 0; + array2[168] = 0; + array2[169] = 0; + array2[170] = 0; + array2[171] = 0; + array2[172] = 0; + array2[173] = 0; + array2[174] = 0; + array2[175] = 0; + array2[176] = 0; + array2[177] = 0; + array2[178] = 0; + array2[179] = 0; + array2[180] = 0; + array2[181] = 0; + array2[182] = 0; + array2[183] = 0; + array2[184] = 0; + array2[185] = 0; + array2[186] = 0; + array2[187] = 0; + array2[188] = 0; + array2[189] = 0; + array2[190] = 0; + array2[191] = 0; + array2[192] = 0; + array2[193] = 0; + array2[194] = 0; + array2[195] = 0; + array2[196] = 0; + array2[197] = 0; + array2[198] = 0; + array2[199] = 0; + if (o1.j >= 20) { + break; + } + o1.j++; + } while(true); + not_inlined4(); + } + + static public void main(String[] args) { + BadPredicateAfterPartialPeel o1 = new BadPredicateAfterPartialPeel(); + BadPredicateAfterPartialPeel o2 = new BadPredicateAfterPartialPeel(); + for (int i = 0; i < 20000; i++) { + o1.j = 0; + m(o1, o2, o2, 0); + m_helper(i, 2, i); // pollute profile + } + } +}