1 /*

     2  * Copyright (c) 2019, 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.replacements.amd64;

    26 

    27 import static org.graalvm.compiler.replacements.NodeIntrinsificationProvider.INJECTED_TARGET;

    28 

    29 import org.graalvm.compiler.api.replacements.ClassSubstitution;

    30 import org.graalvm.compiler.api.replacements.Fold;

    31 import org.graalvm.compiler.api.replacements.MethodSubstitution;

    32 import org.graalvm.compiler.core.common.SuppressFBWarnings;

    33 import org.graalvm.compiler.replacements.nodes.BitScanForwardNode;

    34 import org.graalvm.compiler.replacements.nodes.BitScanReverseNode;

    35 

    36 import jdk.vm.ci.amd64.AMD64;

    37 import jdk.vm.ci.code.TargetDescription;

    38 

    39 @ClassSubstitution(Integer.class)

    40 public class AMD64IntegerSubstitutions {

    41 

    42     @Fold

    43     static boolean lzcnt(@Fold.InjectedParameter TargetDescription target) {

    44         AMD64 arch = (AMD64) target.arch;

    45         return arch.getFeatures().contains(AMD64.CPUFeature.LZCNT) && arch.getFlags().contains(AMD64.Flag.UseCountLeadingZerosInstruction);

    46     }

    47 

    48     @Fold

    49     static boolean tzcnt(@Fold.InjectedParameter TargetDescription target) {

    50         AMD64 arch = (AMD64) target.arch;

    51         return arch.getFeatures().contains(AMD64.CPUFeature.BMI1) && arch.getFlags().contains(AMD64.Flag.UseCountTrailingZerosInstruction);

    52     }

    53 

    54     @MethodSubstitution

    55     @SuppressFBWarnings(value = "NP_NULL_PARAM_DEREF_NONVIRTUAL", justification = "foldable method parameters are injected")

    56     public static int numberOfLeadingZeros(int i) {

    57         if (lzcnt(INJECTED_TARGET)) {

    58             return AMD64CountLeadingZerosNode.countLeadingZeros(i);

    59         }

    60         if (i == 0) {

    61             return 32;

    62         }

    63         return 31 - BitScanReverseNode.unsafeScan(i);

    64     }

    65 

    66     @MethodSubstitution

    67     @SuppressFBWarnings(value = "NP_NULL_PARAM_DEREF_NONVIRTUAL", justification = "foldable method parameters are injected")

    68     public static int numberOfTrailingZeros(int i) {

    69         if (tzcnt(INJECTED_TARGET)) {

    70             return AMD64CountTrailingZerosNode.countTrailingZeros(i);

    71         }

    72         if (i == 0) {

    73             return 32;

    74         }

    75         return BitScanForwardNode.unsafeScan(i);

    76     }

    77 }