1 /*
   2  * Copyright (c) 2011, 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.replacements.amd64;
  24 
  25 import org.graalvm.compiler.api.replacements.ClassSubstitution;
  26 import org.graalvm.compiler.api.replacements.MethodSubstitution;
  27 import org.graalvm.compiler.core.common.spi.ForeignCallDescriptor;
  28 import org.graalvm.compiler.graph.Node.ConstantNodeParameter;
  29 import org.graalvm.compiler.graph.Node.NodeIntrinsic;
  30 import org.graalvm.compiler.nodes.extended.ForeignCallNode;
  31 import org.graalvm.compiler.replacements.nodes.UnaryMathIntrinsicNode;
  32 import org.graalvm.compiler.replacements.nodes.UnaryMathIntrinsicNode.UnaryOperation;
  33 
  34 // JaCoCo Exclude
  35 
  36 /**
  37  * Substitutions for some {@link java.lang.Math} methods that leverage AMD64 instructions for
  38  * selected input values.
  39  */
  40 @ClassSubstitution(Math.class)
  41 public class AMD64MathSubstitutions {
  42 
  43     private static final double PI_4 = Math.PI / 4;
  44 
  45     // NOTE on snippets below:
  46     // Math.sin(), .cos() and .tan() guarantee a value within 1 ULP of the
  47     // exact result, but x87 trigonometric FPU instructions are only that
  48     // accurate within [-pi/4, pi/4]. Examine the passed value and provide
  49     // a slow path for inputs outside of that interval.
  50 
  51     @MethodSubstitution
  52     public static double sin(double x) {
  53         if (Math.abs(x) < PI_4) {
  54             return UnaryMathIntrinsicNode.compute(x, UnaryOperation.SIN);
  55         } else {
  56             return callDouble1(UnaryOperation.SIN.foreignCallDescriptor, x);
  57         }
  58     }
  59 
  60     @MethodSubstitution
  61     public static double cos(double x) {
  62         if (Math.abs(x) < PI_4) {
  63             return UnaryMathIntrinsicNode.compute(x, UnaryOperation.COS);
  64         } else {
  65             return callDouble1(UnaryOperation.COS.foreignCallDescriptor, x);
  66         }
  67     }
  68 
  69     @MethodSubstitution
  70     public static double tan(double x) {
  71         if (Math.abs(x) < PI_4) {
  72             return UnaryMathIntrinsicNode.compute(x, UnaryOperation.TAN);
  73         } else {
  74             return callDouble1(UnaryOperation.TAN.foreignCallDescriptor, x);
  75         }
  76     }
  77 
  78     @NodeIntrinsic(value = ForeignCallNode.class)
  79     private static native double callDouble1(@ConstantNodeParameter ForeignCallDescriptor descriptor, double value);
  80 
  81     @NodeIntrinsic(value = ForeignCallNode.class)
  82     private static native double callDouble2(@ConstantNodeParameter ForeignCallDescriptor descriptor, double a, double b);
  83 }