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			89 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			89 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| // Copyright 2013 the V8 project authors. All rights reserved.
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| // Redistribution and use in source and binary forms, with or without
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| // modification, are permitted provided that the following conditions are
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| // met:
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| //
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| //     * Redistributions of source code must retain the above copyright
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| //       notice, this list of conditions and the following disclaimer.
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| //     * Redistributions in binary form must reproduce the above
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| //       copyright notice, this list of conditions and the following
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| //       disclaimer in the documentation and/or other materials provided
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| //       with the distribution.
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| //     * Neither the name of Google Inc. nor the names of its
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| //       contributors may be used to endorse or promote products derived
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| //       from this software without specific prior written permission.
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| //
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| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 
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| // Flags: --allow-natives-syntax
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| 
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| var X = 1.1;
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| var K = 0.5;
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| 
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| var O = 0;
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| var result = new Float64Array(2);
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| 
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| %NeverOptimizeFunction(spill);
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| function spill() {
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| }
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| 
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| function buggy() {
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|   var v = X;
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|   var phi1 = v + K;
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|   var phi2 = v - K;
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| 
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|   spill();  // At this point initial values for phi1 and phi2 are spilled.
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| 
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|   var xmm1 = v;
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|   var xmm2 = v*v*v;
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|   var xmm3 = v*v*v*v;
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|   var xmm4 = v*v*v*v*v;
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|   var xmm5 = v*v*v*v*v*v;
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|   var xmm6 = v*v*v*v*v*v*v;
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|   var xmm7 = v*v*v*v*v*v*v*v;
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|   var xmm8 = v*v*v*v*v*v*v*v*v;
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| 
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|   // All registers are blocked and phis for phi1 and phi2 are spilled because
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|   // their left (incoming) value is spilled, there are no free registers,
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|   // and phis themselves have only ANY-policy uses.
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| 
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|   for (var x = 0; x < 2; x++) {
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|     xmm1 += xmm1 * xmm6;
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|     xmm2 += xmm1 * xmm5;
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|     xmm3 += xmm1 * xmm4;
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|     xmm4 += xmm1 * xmm3;
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|     xmm5 += xmm1 * xmm2;
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| 
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|     // Now swap values of phi1 and phi2 to create cycle between phis.
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|     var t = phi1;
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|     phi1 = phi2;
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|     phi2 = t;
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|   }
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| 
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|   // Now we want to get values of phi1 and phi2. However we would like to
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|   // do it in a way that does not produce any uses of phi1&phi2 that have
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|   // a register beneficial policy. How? We just hide these uses behind phis.
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|   result[0] = (O === 0) ? phi1 : phi2;
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|   result[1] = (O !== 0) ? phi1 : phi2;
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| }
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| 
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| function test() {
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|   buggy();
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|   assertArrayEquals([X + K, X - K], result);
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| }
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| 
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| test();
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| test();
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| %OptimizeFunctionOnNextCall(buggy);
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| test();
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