From 2cdf61795206675fdfd056d720f181ad45929d4e Mon Sep 17 00:00:00 2001 From: Guanqiang Han Date: Sat, 21 Mar 2026 07:50:03 +0000 Subject: [PATCH] 8372649: C2 compilation fails with "there should be an oop in OopMap instead of a live raw oop at safepoint" Reviewed-by: qamai, chagedorn --- src/hotspot/share/opto/output.cpp | 25 ++++- ...heckCastPPRawOopSchedulingAtSafepoint.java | 103 ++++++++++++++++++ 2 files changed, 122 insertions(+), 6 deletions(-) create mode 100644 test/hotspot/jtreg/compiler/codegen/TestCheckCastPPRawOopSchedulingAtSafepoint.java diff --git a/src/hotspot/share/opto/output.cpp b/src/hotspot/share/opto/output.cpp index edfd6189fb9..a70620fac5b 100644 --- a/src/hotspot/share/opto/output.cpp +++ b/src/hotspot/share/opto/output.cpp @@ -1,5 +1,5 @@ /* - * Copyright (c) 1998, 2025, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 1998, 2026, 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 @@ -2914,17 +2914,30 @@ void Scheduling::ComputeRegisterAntidependencies(Block *b) { Node *m = b->get_node(i); - // Add precedence edge from following safepoint to use of derived pointer - if( last_safept_node != end_node && + if (last_safept_node != end_node && m != last_safept_node) { + bool need_safept_prec = false; + // Add precedence edge from following safepoint to use of derived pointer for (uint k = 1; k < m->req(); k++) { const Type *t = m->in(k)->bottom_type(); - if( t->isa_oop_ptr() && - t->is_ptr()->offset() != 0 ) { - last_safept_node->add_prec( m ); + if (t->isa_oop_ptr() && + t->is_ptr()->offset() != 0) { + need_safept_prec = true; break; } } + // A CheckCastPP whose input is still RawPtr must stay above the following safepoint. + // Otherwise post-regalloc block-local scheduling can leave a live raw oop at the safepoint. + if (!need_safept_prec && m->is_Mach() && + m->as_Mach()->ideal_Opcode() == Op_CheckCastPP) { + Node* def = m->in(1); + if (def != nullptr && def->bottom_type()->base() == Type::RawPtr) { + need_safept_prec = true; + } + } + if (need_safept_prec) { + last_safept_node->add_prec(m); + } } if( n->jvms() ) { // Precedence edge from derived to safept diff --git a/test/hotspot/jtreg/compiler/codegen/TestCheckCastPPRawOopSchedulingAtSafepoint.java b/test/hotspot/jtreg/compiler/codegen/TestCheckCastPPRawOopSchedulingAtSafepoint.java new file mode 100644 index 00000000000..00ba4be76f8 --- /dev/null +++ b/test/hotspot/jtreg/compiler/codegen/TestCheckCastPPRawOopSchedulingAtSafepoint.java @@ -0,0 +1,103 @@ +/* + * Copyright (c) 2026, 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 8372649 8376189 + * @summary CheckCastPP with RawPtr input can be scheduled below a safepoint during C2 + * post-regalloc block-local scheduling, causing a live raw oop at the safepoint + * instead of a corresponding oop in the OopMap. + * @library /test/lib + * @modules jdk.incubator.vector + * @run main/othervm -Xcomp -XX:-TieredCompilation -XX:TrackedInitializationLimit=0 + * -XX:CompileCommand=compileonly,${test.main.class}::test8372649 + * -XX:+OptoScheduling ${test.main.class} 8372649 + * @run main/othervm --add-modules=jdk.incubator.vector + * -XX:+OptoScheduling ${test.main.class} 8376189 + */ + +package compiler.codegen; + +import jdk.incubator.vector.*; +import jdk.test.lib.Asserts; + +public class TestCheckCastPPRawOopSchedulingAtSafepoint { + private static final VectorSpecies SPECIES_I = IntVector.SPECIES_64; + + static public void main(String[] args) { + String mode = args[0]; + if ("8372649".equals(mode)) { + run8372649(); + } else if ("8376189".equals(mode)) { + run8376189(); + } + } + + // JDK-8372649 + static void run8372649(){ + for (int j = 6; 116 > j; ++j) { + test8372649(); + } + Asserts.assertEQ(Test.c, 43560L); + } + + static class Test { + static int a = 256; + float[] b = new float[256]; + static long c; + } + + static void test8372649() { + float[][] g = new float[Test.a][Test.a]; + for (int d = 7; d < 16; d++) { + long e = 1; + do { + g[d][(int) e] = d; + synchronized (new Test()) {} + } while (++e < 5); + } + for (int i = 0; i < Test.a; ++i) { + for (int j = 0; j < Test.a ; ++j) { + Test.c += g[i][j]; + } + } + } + + // JDK-8376189 + static void run8376189(){ + int[] a = new int[10_000]; + int r = 0; + for (int i = 0; i < 10_000; i++) { + r = test8376189(a); + } + Asserts.assertEQ(r, 0); + } + + public static int test8376189(int[] a) { + var mins = IntVector.broadcast(SPECIES_I, a[0]); + for (int i = 0; i < SPECIES_I.loopBound(a.length); i += SPECIES_I.length()) { + mins = IntVector.fromArray(SPECIES_I, a, 0); + } + return mins.reduceLanes(VectorOperators.MIN); + } +} \ No newline at end of file