1// Copyright 2013 the V8 project authors. All rights reserved. 2// Redistribution and use in source and binary forms, with or without 3// modification, are permitted provided that the following conditions are 4// met: 5// 6// * Redistributions of source code must retain the above copyright 7// notice, this list of conditions and the following disclaimer. 8// * Redistributions in binary form must reproduce the above 9// copyright notice, this list of conditions and the following 10// disclaimer in the documentation and/or other materials provided 11// with the distribution. 12// * Neither the name of Google Inc. nor the names of its 13// contributors may be used to endorse or promote products derived 14// from this software without specific prior written permission. 15// 16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28// Flags: --allow-natives-syntax 29 30var X = 1.1; 31var K = 0.5; 32 33var O = 0; 34var result = new Float64Array(2); 35 36function spill() { 37 try { } catch (e) { } 38} 39 40function buggy() { 41 var v = X; 42 var phi1 = v + K; 43 var phi2 = v - K; 44 45 spill(); // At this point initial values for phi1 and phi2 are spilled. 46 47 var xmm1 = v; 48 var xmm2 = v*v*v; 49 var xmm3 = v*v*v*v; 50 var xmm4 = v*v*v*v*v; 51 var xmm5 = v*v*v*v*v*v; 52 var xmm6 = v*v*v*v*v*v*v; 53 var xmm7 = v*v*v*v*v*v*v*v; 54 var xmm8 = v*v*v*v*v*v*v*v*v; 55 56 // All registers are blocked and phis for phi1 and phi2 are spilled because 57 // their left (incoming) value is spilled, there are no free registers, 58 // and phis themselves have only ANY-policy uses. 59 60 for (var x = 0; x < 2; x++) { 61 xmm1 += xmm1 * xmm6; 62 xmm2 += xmm1 * xmm5; 63 xmm3 += xmm1 * xmm4; 64 xmm4 += xmm1 * xmm3; 65 xmm5 += xmm1 * xmm2; 66 67 // Now swap values of phi1 and phi2 to create cycle between phis. 68 var t = phi1; 69 phi1 = phi2; 70 phi2 = t; 71 } 72 73 // Now we want to get values of phi1 and phi2. However we would like to 74 // do it in a way that does not produce any uses of phi1&phi2 that have 75 // a register beneficial policy. How? We just hide these uses behind phis. 76 result[0] = (O === 0) ? phi1 : phi2; 77 result[1] = (O !== 0) ? phi1 : phi2; 78} 79 80function test() { 81 buggy(); 82 assertArrayEquals([X + K, X - K], result); 83} 84 85test(); 86test(); 87%OptimizeFunctionOnNextCall(buggy); 88test(); 89