1 /*
   2  * Copyright (c) 2009, 2018, 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 
  24 
  25 package org.graalvm.compiler.lir.sparc;
  26 
  27 import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.REG;
  28 import static jdk.vm.ci.code.ValueUtil.asRegister;
  29 
  30 import org.graalvm.compiler.asm.sparc.SPARCAssembler;
  31 import org.graalvm.compiler.asm.sparc.SPARCMacroAssembler;
  32 import org.graalvm.compiler.lir.LIR;
  33 import org.graalvm.compiler.lir.LIRInstructionClass;
  34 import org.graalvm.compiler.lir.StandardOp.NoOp;
  35 import org.graalvm.compiler.lir.Variable;
  36 import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
  37 
  38 import jdk.vm.ci.code.Register;
  39 import jdk.vm.ci.meta.AllocatableValue;
  40 
  41 /**
  42  * Loads the constant section base into a register.
  43  *
  44  * <p>
  45  * Layout:
  46  *
  47  * <pre>
  48  * +----constant section----+--pad--+---code section--+
  49  * |<-------------------_------------------->|
  50  *                      ^- Constant section base pointer
  51  * </pre>
  52  *
  53  * The constant section base pointer is placed as such that the lowest offset -4096 points to the
  54  * start of the constant section.
  55  * <p>
  56  * If the constant section grows beyond 8k size, the immediate addressing cannot be used anymore; in
  57  * this case absolute addressing (without using the base pointer is used). See also:
  58  * CodeInstaller::pd_patch_DataSectionReference
  59  *
  60  * @see SPARCMove#loadFromConstantTable(CompilationResultBuilder, SPARCMacroAssembler, Register,
  61  *      jdk.vm.ci.meta.Constant, Register, SPARCDelayedControlTransfer)
  62  */
  63 public class SPARCLoadConstantTableBaseOp extends SPARCLIRInstruction {
  64     public static final LIRInstructionClass<SPARCLoadConstantTableBaseOp> TYPE = LIRInstructionClass.create(SPARCLoadConstantTableBaseOp.class);
  65     public static final SizeEstimate SIZE = SizeEstimate.create(9);
  66 
  67     private final NoOp placeHolder;
  68     @Def({REG}) private AllocatableValue base;
  69 
  70     public SPARCLoadConstantTableBaseOp(Variable base, NoOp placeHolder) {
  71         super(TYPE, SIZE);
  72         this.base = base;
  73         this.placeHolder = placeHolder;
  74     }
  75 
  76     @Override
  77     public void emitCode(CompilationResultBuilder crb, SPARCMacroAssembler masm) {
  78         Register baseRegister = asRegister(base);
  79         int beforePosition = masm.position();
  80         masm.rdpc(baseRegister);
  81         // Must match with CodeInstaller::pd_patch_DataSectionReference
  82         masm.add(baseRegister, (int) SPARCAssembler.minSimm(13), baseRegister);
  83         masm.sub(baseRegister, beforePosition, baseRegister);
  84     }
  85 
  86     public AllocatableValue getResult() {
  87         return base;
  88     }
  89 
  90     public void setAlive(LIR lir, boolean alive) {
  91         if (alive) {
  92             placeHolder.replace(lir, this);
  93         } else {
  94             placeHolder.remove(lir);
  95         }
  96     }
  97 }