1 /*
2 * Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23 package org.graalvm.compiler.hotspot.amd64;
24
25 import static org.graalvm.compiler.core.common.NumUtil.isInt;
26 import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;
27 import static org.graalvm.compiler.core.common.GraalOptions.ImmutableCode;
28 import static jdk.vm.ci.amd64.AMD64.rax;
29 import static jdk.vm.ci.amd64.AMD64.rip;
30
31 import org.graalvm.compiler.asm.amd64.AMD64Address;
32 import org.graalvm.compiler.asm.amd64.AMD64MacroAssembler;
33 import org.graalvm.compiler.core.common.LIRKind;
34 import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;
35 import org.graalvm.compiler.lir.LIRFrameState;
36 import org.graalvm.compiler.lir.LIRInstructionClass;
37 import org.graalvm.compiler.lir.Opcode;
38 import org.graalvm.compiler.lir.amd64.AMD64LIRInstruction;
39 import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
40 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
41
42 import jdk.vm.ci.code.Register;
43 import jdk.vm.ci.code.RegisterValue;
44 import jdk.vm.ci.code.site.InfopointReason;
45 import jdk.vm.ci.meta.AllocatableValue;
46 import jdk.vm.ci.meta.JavaConstant;
47 import jdk.vm.ci.meta.JavaKind;
48 import jdk.vm.ci.meta.Value;
49
50 /**
51 * Emits a safepoint poll.
52 */
53 @Opcode("SAFEPOINT")
54 public final class AMD64HotSpotSafepointOp extends AMD64LIRInstruction {
55 public static final LIRInstructionClass<AMD64HotSpotSafepointOp> TYPE = LIRInstructionClass.create(AMD64HotSpotSafepointOp.class);
56
57 @State protected LIRFrameState state;
58 @Temp({OperandFlag.REG, OperandFlag.ILLEGAL}) private AllocatableValue temp;
59
60 private final GraalHotSpotVMConfig config;
61 private final Register thread;
62
63 public AMD64HotSpotSafepointOp(LIRFrameState state, GraalHotSpotVMConfig config, NodeLIRBuilderTool tool, Register thread) {
64 super(TYPE);
65 this.state = state;
66 this.config = config;
67 this.thread = thread;
68 if (config.threadLocalHandshakes || isPollingPageFar(config) || ImmutableCode.getValue(tool.getOptions())) {
69 temp = tool.getLIRGeneratorTool().newVariable(LIRKind.value(tool.getLIRGeneratorTool().target().arch.getWordKind()));
70 } else {
71 // Don't waste a register if it's unneeded
72 temp = Value.ILLEGAL;
73 }
74 }
75
76 @Override
77 public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler asm) {
78 emitCode(crb, asm, config, false, state, thread, temp instanceof RegisterValue ? ((RegisterValue) temp).getRegister() : null);
79 }
80
81 public static void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler asm, GraalHotSpotVMConfig config, boolean atReturn, LIRFrameState state, Register thread, Register scratch) {
82 if (config.threadLocalHandshakes) {
83 emitThreadLocalPoll(crb, asm, config, atReturn, state, thread, scratch);
84 } else {
85 emitGlobalPoll(crb, asm, config, atReturn, state, scratch);
86 }
87 }
88
89 /**
90 * Tests if the polling page address can be reached from the code cache with 32-bit
91 * displacements.
92 */
93 private static boolean isPollingPageFar(GraalHotSpotVMConfig config) {
94 final long pollingPageAddress = config.safepointPollingAddress;
95 return config.forceUnreachable || !isInt(pollingPageAddress - config.codeCacheLowBound) || !isInt(pollingPageAddress - config.codeCacheHighBound);
96 }
97
98 private static void emitGlobalPoll(CompilationResultBuilder crb, AMD64MacroAssembler asm, GraalHotSpotVMConfig config, boolean atReturn, LIRFrameState state, Register scratch) {
99 assert !atReturn || state == null : "state is unneeded at return";
100 if (ImmutableCode.getValue(crb.getOptions())) {
101 JavaKind hostWordKind = JavaKind.Long;
102 int alignment = hostWordKind.getBitCount() / Byte.SIZE;
103 JavaConstant pollingPageAddress = JavaConstant.forIntegerKind(hostWordKind, config.safepointPollingAddress);
104 // This move will be patched to load the safepoint page from a data segment
105 // co-located with the immutable code.
106 if (GeneratePIC.getValue(crb.getOptions())) {
107 asm.movq(scratch, asm.getPlaceholder(-1));
108 } else {
109 asm.movq(scratch, (AMD64Address) crb.recordDataReferenceInCode(pollingPageAddress, alignment));
110 }
111 final int pos = asm.position();
112 crb.recordMark(atReturn ? config.MARKID_POLL_RETURN_FAR : config.MARKID_POLL_FAR);
113 if (state != null) {
114 crb.recordInfopoint(pos, state, InfopointReason.SAFEPOINT);
115 }
116 asm.testl(rax, new AMD64Address(scratch));
117 } else if (isPollingPageFar(config)) {
118 asm.movq(scratch, config.safepointPollingAddress);
119 crb.recordMark(atReturn ? config.MARKID_POLL_RETURN_FAR : config.MARKID_POLL_FAR);
120 final int pos = asm.position();
121 if (state != null) {
122 crb.recordInfopoint(pos, state, InfopointReason.SAFEPOINT);
123 }
124 asm.testl(rax, new AMD64Address(scratch));
125 } else {
126 crb.recordMark(atReturn ? config.MARKID_POLL_RETURN_NEAR : config.MARKID_POLL_NEAR);
127 final int pos = asm.position();
128 if (state != null) {
129 crb.recordInfopoint(pos, state, InfopointReason.SAFEPOINT);
130 }
131 // The C++ code transforms the polling page offset into an RIP displacement
132 // to the real address at that offset in the polling page.
133 asm.testl(rax, new AMD64Address(rip, 0));
134 }
135 }
136
137 private static void emitThreadLocalPoll(CompilationResultBuilder crb, AMD64MacroAssembler asm, GraalHotSpotVMConfig config, boolean atReturn, LIRFrameState state, Register thread,
138 Register scratch) {
139 assert !atReturn || state == null : "state is unneeded at return";
140
141 assert config.threadPollingPageOffset >= 0;
142 asm.movptr(scratch, new AMD64Address(thread, config.threadPollingPageOffset));
143 crb.recordMark(atReturn ? config.MARKID_POLL_RETURN_FAR : config.MARKID_POLL_FAR);
144 final int pos = asm.position();
145 if (state != null) {
146 crb.recordInfopoint(pos, state, InfopointReason.SAFEPOINT);
147 }
148 asm.testl(rax, new AMD64Address(scratch));
149 }
150 }