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 // JaCoCo Exclude

    28 

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

    30 

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

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

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

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

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

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

    37 

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

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

    40 

    41 @ClassSubstitution(Long.class)

    42 public class AMD64LongSubstitutions {

    43 

    44     @Fold

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

    46         AMD64 arch = (AMD64) target.arch;

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

    48     }

    49 

    50     @Fold

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

    52         AMD64 arch = (AMD64) target.arch;

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

    54     }

    55 

    56     @MethodSubstitution

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

    58     public static int numberOfLeadingZeros(long i) {

    59         if (lzcnt(INJECTED_TARGET)) {

    60             return AMD64CountLeadingZerosNode.countLeadingZeros(i);

    61         }

    62         if (i == 0) {

    63             return 64;

    64         }

    65         return 63 - BitScanReverseNode.unsafeScan(i);

    66     }

    67 

    68     @MethodSubstitution

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

    70     public static int numberOfTrailingZeros(long i) {

    71         if (tzcnt(INJECTED_TARGET)) {

    72             return AMD64CountTrailingZerosNode.countTrailingZeros(i);

    73         }

    74 

    75         if (i == 0) {

    76             return 64;

    77         }

    78         return BitScanForwardNode.unsafeScan(i);

    79     }

    80 }