/*
 * Copyright (c) 2013, 2018, 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.
 */


package org.graalvm.compiler.lir.aarch64;

import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.CONST;
import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.REG;
import static org.graalvm.compiler.lir.LIRValueUtil.asJavaConstant;
import static org.graalvm.compiler.lir.LIRValueUtil.isJavaConstant;
import static jdk.vm.ci.code.ValueUtil.asRegister;
import static jdk.vm.ci.code.ValueUtil.isRegister;

import org.graalvm.compiler.core.common.NumUtil;
import org.graalvm.compiler.asm.aarch64.AArch64Assembler;
import org.graalvm.compiler.asm.aarch64.AArch64MacroAssembler;
import org.graalvm.compiler.core.common.calc.Condition;
import org.graalvm.compiler.debug.GraalError;
import org.graalvm.compiler.lir.LIRInstructionClass;
import org.graalvm.compiler.lir.asm.CompilationResultBuilder;

import jdk.vm.ci.aarch64.AArch64Kind;
import jdk.vm.ci.meta.JavaConstant;
import jdk.vm.ci.meta.Value;

public class AArch64Compare {

    public static class CompareOp extends AArch64LIRInstruction {
        public static final LIRInstructionClass<CompareOp> TYPE = LIRInstructionClass.create(CompareOp.class);

        @Use protected Value x;
        @Use({REG, CONST}) protected Value y;

        public CompareOp(Value x, Value y) {
            super(TYPE);
            assert ((AArch64Kind) x.getPlatformKind()).isInteger() && ((AArch64Kind) y.getPlatformKind()).isInteger();
            assert x.getPlatformKind() == y.getPlatformKind();
            this.x = x;
            this.y = y;
        }

        @Override
        public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {
            gpCompare(masm, x, y);
        }
    }

    
Compares integer values x and y.
Params:
  • x – integer value to compare. May not be null.
  • y – integer value to compare. May not be null.
/** * Compares integer values x and y. * * @param x integer value to compare. May not be null. * @param y integer value to compare. May not be null. */
public static void gpCompare(AArch64MacroAssembler masm, Value x, Value y) { final int size = x.getPlatformKind().getSizeInBytes() * Byte.SIZE; if (isRegister(y)) { masm.cmp(size, asRegister(x), asRegister(y)); } else { JavaConstant constant = asJavaConstant(y); if (constant.isDefaultForKind()) { masm.cmp(size, asRegister(x), 0); } else { final long longValue = constant.asLong(); assert NumUtil.isInt(longValue); int maskedValue; switch (constant.getJavaKind()) { case Boolean: case Byte: maskedValue = (int) (longValue & 0xFF); break; case Char: case Short: maskedValue = (int) (longValue & 0xFFFF); break; case Int: case Long: maskedValue = (int) longValue; break; default: throw GraalError.shouldNotReachHere(); } masm.cmp(size, asRegister(x), maskedValue); } } } public static class FloatCompareOp extends AArch64LIRInstruction { public static final LIRInstructionClass<FloatCompareOp> TYPE = LIRInstructionClass.create(FloatCompareOp.class); @Use protected Value x; @Use({REG, CONST}) protected Value y; private final Condition condition; private final boolean unorderedIsTrue; public FloatCompareOp(Value x, Value y, Condition condition, boolean unorderedIsTrue) { super(TYPE); assert !isJavaConstant(y) || isFloatCmpConstant(y, condition, unorderedIsTrue); this.x = x; this.y = y; this.condition = condition; this.unorderedIsTrue = unorderedIsTrue; }
Checks if val can be used as a constant for the gpCompare operation or not.
/** * Checks if val can be used as a constant for the gpCompare operation or not. */
public static boolean isFloatCmpConstant(Value val, Condition condition, boolean unorderedIsTrue) { // If the condition is "EQ || unordered" or "NE && unordered" we have to use 2 registers // in any case. if (!(condition == Condition.EQ && unorderedIsTrue || condition == Condition.NE && !unorderedIsTrue)) { return false; } return isJavaConstant(val) && asJavaConstant(val).isDefaultForKind(); } @Override public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) { assert isRegister(x); int size = x.getPlatformKind().getSizeInBytes() * Byte.SIZE; if (isRegister(y)) { masm.fcmp(size, asRegister(x), asRegister(y)); // There is no condition code for "EQ || unordered" nor one for "NE && unordered", // so we have to fix them up ourselves. // In both cases we combine the asked for condition into the EQ, respectively NE // condition, i.e. // if EQ && unoreredIsTrue, then the EQ flag will be set if the two values gpCompare // unequal but are // unordered. if (condition == Condition.EQ && unorderedIsTrue) { // if f1 ordered f2: // result = f1 == f2 // else: // result = EQUAL int nzcv = 0b0100; // EQUAL -> Z = 1 masm.fccmp(size, asRegister(x), asRegister(y), nzcv, AArch64Assembler.ConditionFlag.VC); } else if (condition == Condition.NE && !unorderedIsTrue) { // if f1 ordered f2: // result = f1 != f2 // else: // result = !NE == EQUAL int nzcv = 0b0100; // EQUAL -> Z = 1 masm.fccmp(size, asRegister(x), asRegister(y), nzcv, AArch64Assembler.ConditionFlag.VC); } } else { // cmp against +0.0 masm.fcmpZero(size, asRegister(x)); } } @Override public void verify() { assert x.getPlatformKind().equals(y.getPlatformKind()) : "a: " + x + " b: " + y; } } }