1 /*
   2  * Copyright (c) 2015, 2015, 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.lir.alloc.lsra.ssa;
  24 
  25 import org.graalvm.compiler.core.common.alloc.RegisterAllocationConfig;
  26 import org.graalvm.compiler.core.common.cfg.AbstractBlockBase;
  27 import org.graalvm.compiler.debug.Debug;
  28 import org.graalvm.compiler.debug.Debug.Scope;
  29 import org.graalvm.compiler.lir.alloc.lsra.LinearScan;
  30 import org.graalvm.compiler.lir.alloc.lsra.LinearScanEliminateSpillMovePhase;
  31 import org.graalvm.compiler.lir.alloc.lsra.LinearScanLifetimeAnalysisPhase;
  32 import org.graalvm.compiler.lir.alloc.lsra.LinearScanResolveDataFlowPhase;
  33 import org.graalvm.compiler.lir.alloc.lsra.MoveResolver;
  34 import org.graalvm.compiler.lir.gen.LIRGenerationResult;
  35 import org.graalvm.compiler.lir.gen.LIRGeneratorTool.MoveFactory;
  36 import org.graalvm.compiler.lir.ssa.SSAUtil;
  37 
  38 import jdk.vm.ci.code.TargetDescription;
  39 
  40 public final class SSALinearScan extends LinearScan {
  41 
  42     public SSALinearScan(TargetDescription target, LIRGenerationResult res, MoveFactory spillMoveFactory, RegisterAllocationConfig regAllocConfig, AbstractBlockBase<?>[] sortedBlocks,
  43                     boolean neverSpillConstants) {
  44         super(target, res, spillMoveFactory, regAllocConfig, sortedBlocks, neverSpillConstants);
  45     }
  46 
  47     @Override
  48     protected MoveResolver createMoveResolver() {
  49         SSAMoveResolver moveResolver = new SSAMoveResolver(this);
  50         assert moveResolver.checkEmpty();
  51         return moveResolver;
  52     }
  53 
  54     @Override
  55     protected LinearScanLifetimeAnalysisPhase createLifetimeAnalysisPhase() {
  56         return new SSALinearScanLifetimeAnalysisPhase(this);
  57     }
  58 
  59     @Override
  60     protected LinearScanResolveDataFlowPhase createResolveDataFlowPhase() {
  61         return new SSALinearScanResolveDataFlowPhase(this);
  62     }
  63 
  64     @Override
  65     protected LinearScanEliminateSpillMovePhase createSpillMoveEliminationPhase() {
  66         return new SSALinearScanEliminateSpillMovePhase(this);
  67     }
  68 
  69     @Override
  70     @SuppressWarnings("try")
  71     protected void beforeSpillMoveElimination() {
  72         /*
  73          * PHI Ins are needed for the RegisterVerifier, otherwise PHIs where the Out and In value
  74          * matches (ie. there is no resolution move) are falsely detected as errors.
  75          */
  76         try (Scope s1 = Debug.scope("Remove Phi In")) {
  77             for (AbstractBlockBase<?> toBlock : sortedBlocks()) {
  78                 if (toBlock.getPredecessorCount() > 1) {
  79                     SSAUtil.removePhiIn(getLIR(), toBlock);
  80                 }
  81             }
  82         }
  83     }
  84 
  85 }