Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 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 | |
| 30 | var X = 1.1; |
| 31 | var K = 0.5; |
| 32 | |
| 33 | var O = 0; |
| 34 | var result = new Float64Array(2); |
| 35 | |
| 36 | function spill() { |
| 37 | try { } catch (e) { } |
| 38 | } |
| 39 | |
| 40 | function 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 | |
| 80 | function test() { |
| 81 | buggy(); |
| 82 | assertArrayEquals([X + K, X - K], result); |
| 83 | } |
| 84 | |
| 85 | test(); |
| 86 | test(); |
| 87 | %OptimizeFunctionOnNextCall(buggy); |
| 88 | test(); |