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      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.
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     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
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     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 %NeverOptimizeFunction(spill);
     37 function spill() {
     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();
     89