You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

107 lines
3.9 KiB

// Copyright 2010 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * 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.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
// OWNER 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.
// Flags: --always-opt --nocompilation-cache
// Given a binary operation string and an ordered array of leaf
// strings, return an array of all binary tree strings with the leaves
// (in order) as the fringe.
function makeTrees(op, leaves) {
var len = leaves.length;
if (len == 1) {
// One leaf is a leaf.
return leaves;
} else {
// More than one leaf requires an interior node.
var result = [];
// Split the leaves into left and right subtrees in all possible
// ways. For each split recursively compute all possible subtrees.
for (var i = 1; i < len; ++i) {
var leftTrees = makeTrees(op, leaves.slice(0, i));
var rightTrees = makeTrees(op, leaves.slice(i, len));
// Adjoin every possible left and right subtree.
for (var j = 0; j < leftTrees.length; ++j) {
for (var k = 0; k < rightTrees.length; ++k) {
var string = "(" + leftTrees[j] + op + rightTrees[k] + ")";
result.push(string);
}
}
}
return result;
}
}
// All 429 possible bitwise OR trees with eight leaves.
var identifiers = ['a','b','c','d','e','f','g','h'];
var or_trees = makeTrees("|", identifiers);
var and_trees = makeTrees("&", identifiers);
// Set up leaf masks to set 8 least-significant bits.
var a = 1 << 0;
var b = 1 << 1;
var c = 1 << 2;
var d = 1 << 3;
var e = 1 << 4;
var f = 1 << 5;
var g = 1 << 6;
var h = 1 << 7;
for (var i = 0; i < or_trees.length; ++i) {
for (var j = 0; j < 8; ++j) {
var or_fun = new Function("return " + or_trees[i]);
if (j == 0) assertEquals(255, or_fun());
// Set the j'th variable to a string to force a bailout.
eval(identifiers[j] + "+= ''");
assertEquals(255, or_fun());
// Set it back to a number for the next iteration.
eval(identifiers[j] + "= +" + identifiers[j]);
}
}
// Set up leaf masks to clear 8 least-significant bits.
a ^= 255;
b ^= 255;
c ^= 255;
d ^= 255;
e ^= 255;
f ^= 255;
g ^= 255;
h ^= 255;
for (i = 0; i < and_trees.length; ++i) {
for (var j = 0; j < 8; ++j) {
var and_fun = new Function("return " + and_trees[i]);
if (j == 0) assertEquals(0, and_fun());
// Set the j'th variable to a string to force a bailout.
eval(identifiers[j] + "+= ''");
assertEquals(0, and_fun());
// Set it back to a number for the next iteration.
eval(identifiers[j] + "= +" + identifiers[j]);
}
}