v8/test/mjsunit/compiler/dead-code6.js

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// Flags: --allow-natives-syntax
// Test some dead code elimination scenarios

function dead1(x, y) {
    var a = x | 0, b = y | 0;
    a * b;
    a << b;
    a >> b;
    a >>> b;
    a | b;
    a & b;
    a ^ b;
    return x;
}

function dead2(x, y) {
    var a = x | 0, b = y | 0;
    (a | 0) * b;
    (a | 0) << b;
    (a | 0) >> b;
    (a | 0) >>> b;
    (a | 0) | b;
    (a | 0) & b;
    (a | 0) ^ b;
    return x;
}

function dead3(a, b) {
    a == 2 ? (a * b) : (b * a); // dead
    return a;
}

%PrepareFunctionForOptimization(dead1);
assertTrue(dead1(33, 32) == 33);
assertTrue(dead1(33, 32) == 33);
%OptimizeFunctionOnNextCall(dead1);
assertTrue(dead1(33, 32) == 33);

%PrepareFunctionForOptimization(dead2);
assertTrue(dead2(34, 11) == 34);
assertTrue(dead2(34, 11) == 34);
%OptimizeFunctionOnNextCall(dead2);
assertTrue(dead2(34, 11) == 34);

%PrepareFunctionForOptimization(dead3);
assertTrue(dead3(35, 12) == 35);
assertTrue(dead3(35, 12) == 35);
%OptimizeFunctionOnNextCall(dead3);
assertTrue(dead3(35, 12) == 35);