Extend bounds check elimination to constant keys.

test/mjsunit/bounds-checks-elimination.js

+// 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 --array-bounds-checks-elimination
+
+var a = []
+for (var i = 0; i < 9; i++) a[i] = i + 1;
+
+function test(f, arg1, arg2, expected) {
+  assertEquals(expected, f(arg1));
+  f(arg2);
+  %OptimizeFunctionOnNextCall(f);
+  assertEquals(expected, f(arg1));
+}
+
+test(function f0() {
+  return a[7] * a[6] * a[5] * a[4] * a[3] * a[2] * a[1] * a[0];
+}, 0, 1, 40320);
+
+test(function f1() {
+  return a[7] * a[6] * a[5] * a[4] * a[10] * a[2] * a[1] * a[0];
+}, 0, 1, NaN);
+
+test(function f2() {
+  return a[0] * a[1] * a[2] * a[3] * a[4] * a[5] * a[6] * a[7];
+}, 0, 1, 40320);
+
+test(function f3() {
+  return a[3] * a[0] * a[6] * a[7] * a[5] * a[1] * a[4] * a[2];
+}, 0, 1, 40320);
+
+test(function f4(b) {
+  return a[b+3] * a[0] * a[b+6] * a[7] * a[b+5] * a[1] * a[b+4] * a[2];
+}, 0, 1, 40320);
+
+test(function f5(b) {
+  return a[b+1] * a[0] * a[b+4] * a[7] * a[b+3] * a[1] * a[b+2] * a[2];
+}, 2, 3, 40320);
+
+test(function f6(b) {
+  var c;
+  if (b) c = a[3] * a[0] * a[6] * a[7];
+  return c * a[5] * a[1] * a[4] * a[2];
+}, true, false, 40320);
+
+test(function f7(b) {
+  var c = a[7];
+  if (b) c *= a[3] * a[0] * a[6];
+  return c * a[5] * a[1] * a[4] * a[2];
+}, true, false, 40320);
+
+test(function f8(b) {
+  var c = a[7];
+  if (b) c *= a[3] * a[0] * a[6];
+  return c * a[5] * a[10] * a[4] * a[2];
+}, true, false, NaN);
+
+test(function f9(b) {
+  var c = a[1];
+  if (b) {
+    c *= a[3] * a[0] * a[6];
+  } else {
+    c = a[6] * a[5] * a[4];
+  }
+  return c * a[5] * a[7] * a[4] * a[2];
+}, true, false, 40320);
+
+test(function fa(b) {
+  var c = a[1];
+  if (b) {
+    c = a[6] * a[b+5] * a[4];
+  } else {
+    c *= a[b+3] * a[0] * a[b+6];
+  }
+  return c * a[5] * a[b+7] * a[4] * a[2];
+}, 0, 1, 40320);
+
+test(function fb(b) {
+  var c = a[b-3];
+  if (b != 4) {
+    c = a[6] * a[b+1] * a[4];
+  } else {
+    c *= a[b-1] * a[0] * a[b+2];
+  }
+  return c * a[5] * a[b+3] * a[4] * a[b-2];
+}, 4, 3, 40320);
+
+test(function fc(b) {
+  var c = a[b-3];
+  if (b != 4) {
+    c = a[6] * a[b+1] * a[4];
+  } else {
+    c *= a[b-1] * a[0] * a[b+2];
+  }
+  return c * a[5] * a[b+3] * a[4] * a[b-2];
+}, 6, 3, NaN);
+
+test(function fd(b) {
+  var c = a[b-3];
+  if (b != 4) {
+    c = a[6] * a[b+1] * a[4];
+  } else {
+    c *= a[b-1] * a[0] * a[b+2];
+  }
+  return c * a[5] * a[b+3] * a[4] * a[b-2];
+}, 1, 4, NaN);
+
+test(function fe(b) {
+  var c = 1;
+  for (var i = 1; i < b-1; i++) {
+    c *= a[i-1] * a[i] * a[i+1];
+  }
+  return c;
+}, 8, 4, (40320 / 8 / 7) * (40320 / 8) * (40320 / 2));
+
+test(function ff(b) {
+  var c = 0;
+  for (var i = 0; i < b; i++) {
+    c += a[3] * a[0] * a[6] * a[7] * a[5] * a[1] * a[4] * a[2];
+  }
+  return c;
+}, 100, 4, 40320 * 100);