A64: Add support for SMI representation to MulConstI. Also add a test.

test/mjsunit/smi-mul-const.js

+// Copyright 2014 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: --allow-natives-syntax --noalways-opt
+
+function check(func, input, expected) {
+  func(-1);
+  func(-1);
+  %OptimizeFunctionOnNextCall(func);
+  assertEquals(expected, func(input));
+  assertOptimized(func);
+}
+
+function mul_by_neg_1(a) { return a * -1; }
+function mul_by_0(a) {  return a * 0; }
+function mul_by_1(a) { return a * 1; }
+function mul_by_2(a) { return a * 2; }
+
+check(mul_by_neg_1, 2, -2);
+check(mul_by_0, 2, 0);
+check(mul_by_1, 2, 2);
+check(mul_by_2, 2, 4);
+
+function limit_range(a) {
+  // Limit the range of 'a' to enable no-overflow optimizations.
+  return Math.max(Math.min(a | 0, 10), -10);
+}
+
+function mul_by_neg_127(a) { return limit_range(a) * -127; }
+function mul_by_neg_128(a) { return limit_range(a) * -128; }
+function mul_by_neg_129(a) { return limit_range(a) * -129; }
+function mul_by_1023(a) { return limit_range(a) * 1023; }
+function mul_by_1024(a) { return limit_range(a) * 1024; }
+function mul_by_1025(a) { return limit_range(a) * 1025; }
+
+check(mul_by_neg_127, 2, -254);
+check(mul_by_neg_128, 2, -256);
+check(mul_by_neg_129, 2, -258);
+check(mul_by_1023, 2, 2046);
+check(mul_by_1024, 2, 2048);
+check(mul_by_1025, 2, 2050);
+
+// Deopt on minus zero.
+assertEquals(-0, mul_by_neg_128(0));
+assertUnoptimized(mul_by_neg_128);
+assertEquals(-0, mul_by_2(-0));
+assertUnoptimized(mul_by_2);
+
+// Deopt on overflow.
+
+// 2^30 is a smi boundary on arm and ia32.
+var two_30 = 1 << 30;
+// 2^31 is a smi boundary on arm64 and x64.
+var two_31 = 2 * two_30;
+
+// TODO(rmcilroy): replace after r16361 with:  if (%IsValidSmi(two_31)) {
+if (true) {
+  assertEquals(two_31, mul_by_neg_1(-two_31));
+  assertUnoptimized(mul_by_neg_1);
+} else {
+  assertEquals(two_30, mul_by_neg_1(-two_30));
+  assertUnoptimized(mul_by_neg_1);
+}