v8/test/mjsunit/compiler/shift-shr.js
neis 42ded33b5b [compiler] Speculate a little more in SpeculativeShiftRightLogical.
If the RHS is 0 and we have Smi feedback, speculate that the result (the LHS)
will continue to be in the Unsigned31 range.  This helps us avoid converting
the result to double when merging with Signed32.

R=jarin@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2709423002
Cr-Commit-Position: refs/heads/master@{#43415}
2017-02-24 14:39:38 +00:00

56 lines
1.1 KiB
JavaScript

// Copyright 2014 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --allow-natives-syntax
// Check the results of `left >>> right`. The result is always unsigned (and
// therefore positive).
function test_shr(left) {
var errors = 0;
for (var i = 1; i < 1024; i++) {
var temp = left >>> i;
if (temp < 0) {
errors++;
}
}
return errors;
}
assertEquals(0, test_shr(1));
%OptimizeFunctionOnNextCall(test_shr);
for (var i = 5; i >= -5; i--) {
assertEquals(0, test_shr(i));
}
(function () {
function foo(x, b, array) {
var y;
x = x >>> 0;
b ? (y = x | 0) : (y = x);
return array[y];
}
foo(111, true, new Array(42));
foo(111, true, new Array(42));
%OptimizeFunctionOnNextCall(foo);
foo(-111, true, new Array(42));
})();
(function () {
function foo(x, b, array) {
var y;
x = x >>> 0;
b ? (y = x | 0) : (y = x);
return array[y];
}
foo(111, true, new Array(42));
foo(111, true, new Array(42));
%OptimizeFunctionOnNextCall(foo);
foo(111, true, new Array(42));
})();