JSTests/stress/pow-coherency.js

//@ skip

// This test checks that the pow function returns coherent results:
// (a) Across different compilation tiers
// (b) With integer exponents represented as int32 or as double

function pow42() {
    return { value: 2.1 ** 42, ftl: isFinalTier() };
}

function build42AsDouble() {
    function opaqueAdd(x, y) { return x + y; }
    return opaqueAdd(42 - 0.123, 0.123);
}

var double42 = build42AsDouble();

if (double42 !== 42)
    throw new Error("42 (as double) should be === to 42 (as int)");

function powDouble42() {
    return { value: 2.1 ** double42, ftl: isFinalTier() };
}

function clobber() { }
noInline(clobber);

function pow42NoConstantFolding() {
    var obj = { x: 2.1, y: 42 };
    clobber(obj);
    return { value: obj.x ** obj.y, ftl: isFinalTier() };
}

function powDouble42NoConstantFolding() {
    var obj = { x: 2.1, y: double42 };
    clobber(obj);
    return { value: obj.x ** obj.y, ftl: isFinalTier() };
}

var results = { 'jit': {}, 'dfg': {}, 'ftl': {} };
var funs = [
    [ 'pow42', pow42 ],
    [ 'powDouble42', powDouble42 ],
    [ 'pow42NoConstantFolding', pow42NoConstantFolding ],
    [ 'powDouble42NoConstantFolding', powDouble42NoConstantFolding ]
];
var tiers = ['jit', 'dfg', 'ftl'];

for (var i = 0; i < 100000; ++i) {
    for (var j in funs) {
        var name = funs[j][0];
        var fun = funs[j][1];
        var result = fun();
        if (result.ftl)
            results['ftl'][name] = result.value;
        else if (numberOfDFGCompiles(fun) > 0)
            results['dfg'][name] = result.value;
        else
            results['jit'][name] = result.value;
    }
}

var errors = [];
var valuesFor = {};
for (var i in tiers) {
    var tier = tiers[i];
    var result = results[tier];
    // We don't have this tier
    if (Object.keys(result).length === 0)
        continue;

    for (var j in funs) {
        var name = funs[j][0];
        if (!(name in result))
            errors.push(name + " was not compiled to " + tier);
        else if (!(name in valuesFor))
            valuesFor[name] = { value: result[name], tiers: [tier] };
        else if (result[name] !== valuesFor[name].value)
            errors.push(name + " has different results in " + tier + " (" + result[name] + ") and " + valuesFor[name].tiers + " (" + valuesFor[name].value + ")");
        else
            valuesFor[name].tiers.push(tier);
    }
}

var reference = funs[0][0];
var result = valuesFor[reference].value;

for (var j in funs) {
    var name = funs[j][0];
    if (valuesFor[name].value !== result)
        errors.push(name + " (" + valuesFor[name].value + ") and " + reference + " (" + result + ") have different results");
}

if (errors.length > 0)
    throw new Error(errors.join('\n'));