| /* |
| * Copyright (C) Rich Moore. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY CONTRIBUTORS ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /////. Start CORDIC |
| |
| var AG_CONST = 0.6072529350; |
| |
| function FIXED(X) |
| { |
| return X * 65536.0; |
| } |
| |
| function FLOAT(X) |
| { |
| return X / 65536.0; |
| } |
| |
| function DEG2RAD(X) |
| { |
| return 0.017453 * (X); |
| } |
| |
| var Angles = [ |
| FIXED(45.0), FIXED(26.565), FIXED(14.0362), FIXED(7.12502), |
| FIXED(3.57633), FIXED(1.78991), FIXED(0.895174), FIXED(0.447614), |
| FIXED(0.223811), FIXED(0.111906), FIXED(0.055953), |
| FIXED(0.027977) |
| ]; |
| |
| var Target = 28.027; |
| |
| function cordicsincos(Target) { |
| var X; |
| var Y; |
| var TargetAngle; |
| var CurrAngle; |
| var Step; |
| |
| X = FIXED(AG_CONST); /* AG_CONST * cos(0) */ |
| Y = 0; /* AG_CONST * sin(0) */ |
| |
| TargetAngle = FIXED(Target); |
| CurrAngle = 0; |
| for (Step = 0; Step < 12; Step++) { |
| var NewX; |
| if (TargetAngle > CurrAngle) { |
| NewX = X - (Y >> Step); |
| Y = (X >> Step) + Y; |
| X = NewX; |
| CurrAngle += Angles[Step]; |
| } else { |
| NewX = X + (Y >> Step); |
| Y = -(X >> Step) + Y; |
| X = NewX; |
| CurrAngle -= Angles[Step]; |
| } |
| } |
| |
| return FLOAT(X) * FLOAT(Y); |
| } |
| |
| ///// End CORDIC |
| |
| var total = 0; |
| |
| function cordic( runs ) { |
| var start = new Date(); |
| |
| for ( var i = 0 ; i < runs ; i++ ) { |
| total += cordicsincos(Target); |
| } |
| |
| var end = new Date(); |
| |
| return end.getTime() - start.getTime(); |
| } |
| |
| cordic(13000000); |
| |
| var expected = 5388536.644120298; |
| |
| if (total != expected) |
| throw "ERROR: bad result: expected " + expected + " but got " + total; |
| |