1 /* 2 * Copyright (c) 2013, 2016, 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.aarch64; 24 25 import static jdk.vm.ci.aarch64.AArch64.zr; 26 import static jdk.vm.ci.code.ValueUtil.asRegister; 27 28 import org.graalvm.compiler.asm.NumUtil; 29 import org.graalvm.compiler.asm.aarch64.AArch64Address; 30 import org.graalvm.compiler.asm.aarch64.AArch64MacroAssembler; 31 import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig; 32 import org.graalvm.compiler.lir.LIRFrameState; 33 import org.graalvm.compiler.lir.LIRInstructionClass; 34 import org.graalvm.compiler.lir.Opcode; 35 import org.graalvm.compiler.lir.aarch64.AArch64LIRInstruction; 36 import org.graalvm.compiler.lir.asm.CompilationResultBuilder; 37 38 import jdk.vm.ci.code.Register; 39 import jdk.vm.ci.code.site.InfopointReason; 40 import jdk.vm.ci.meta.AllocatableValue; 41 42 /** 43 * Emits a safepoint poll. 44 */ 45 @Opcode("SAFEPOINT") 46 public class AArch64HotSpotSafepointOp extends AArch64LIRInstruction { 47 public static final LIRInstructionClass<AArch64HotSpotSafepointOp> TYPE = LIRInstructionClass.create(AArch64HotSpotSafepointOp.class); 48 49 @State protected LIRFrameState state; 50 @Temp protected AllocatableValue scratchValue; 51 52 private final GraalHotSpotVMConfig config; 53 54 public AArch64HotSpotSafepointOp(LIRFrameState state, GraalHotSpotVMConfig config, AllocatableValue scratch) { 55 super(TYPE); 56 this.state = state; 57 this.config = config; 58 this.scratchValue = scratch; 59 } 60 61 @Override 62 public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) { 63 Register scratch = asRegister(scratchValue); 64 emitCode(crb, masm, config, false, scratch, state); 65 } 66 67 /** 68 * Conservatively checks whether we can load the safepoint polling address with a single ldr 69 * instruction or not. 70 * 71 * @return true if it is guaranteed that polling page offset will always fit into a 21-bit 72 * signed integer, false otherwise. 73 */ 74 private static boolean isPollingPageFar(GraalHotSpotVMConfig config) { 75 final long pollingPageAddress = config.safepointPollingAddress; 76 return !NumUtil.isSignedNbit(21, pollingPageAddress - config.codeCacheLowBound) || !NumUtil.isSignedNbit(21, pollingPageAddress - config.codeCacheHighBound); 77 } 78 79 public static void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm, GraalHotSpotVMConfig config, boolean onReturn, Register scratch, LIRFrameState state) { 80 int pos = masm.position(); 81 if (isPollingPageFar(config)) { 82 crb.recordMark(onReturn ? config.MARKID_POLL_RETURN_FAR : config.MARKID_POLL_FAR); 83 masm.movNativeAddress(scratch, config.safepointPollingAddress); 84 if (state != null) { 85 crb.recordInfopoint(pos, state, InfopointReason.SAFEPOINT); 86 } 87 masm.ldr(32, zr, AArch64Address.createBaseRegisterOnlyAddress(scratch)); 88 } else { 89 crb.recordMark(onReturn ? config.MARKID_POLL_RETURN_NEAR : config.MARKID_POLL_NEAR); 90 if (state != null) { 91 crb.recordInfopoint(pos, state, InfopointReason.SAFEPOINT); 92 } 93 masm.ldr(32, zr, AArch64Address.createPcLiteralAddress(0)); 94 } 95 } 96 97 }