Allow control intructions to have side effects.

test/mjsunit/compare-generic.js

+// Copyright 2013 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
+
+// Test the correct placement of the simulates after HCompareGenericAndBranch:
+function Checker() {
+  this.str = "1";
+  var toStringCalled = 0;
+  var toStringExpected = 0;
+  this.toString = function() {
+    toStringCalled++;
+    return this.str;
+  };
+  this.check = function() {
+    toStringExpected++;
+    assertEquals(toStringExpected, toStringCalled);
+  };
+};
+var left = new Checker();
+var right = new Checker();
+
+// This test compares a < b against x < y where
+// x/y are objects providing a/b as toString. In the end we
+// check if the observable side effects match our
+// expectations, thus we make sure that we deopted to a
+// simulate after the comparison was done.
+function test(a,b) {
+  left.str = a;
+  right.str = b;
+  if (left >= right) {
+    assertTrue(a >= b);
+  } else {
+    assertFalse(a >= b);
+  }
+  left.check();
+  right.check();
+}
+
+test("ab","abc");
+test("ab","a");
+%OptimizeFunctionOnNextCall(test);
+test("a","ab");
+test(1,"a");
+test("a","ab");
+%OptimizeFunctionOnNextCall(test);
+test("a","ab");
+test("a",1);
+test("ab","a");
+
+
+// Use generic compare in value, effect and test contexts
+
+function Checker2() {
+  var valueOfCalled = 0;
+  this.valueOf = function() {
+    return valueOfCalled++;
+  }
+  this.valueOfCalled = function() {
+    return valueOfCalled;
+  }
+}
+
+var x = new Checker2();
+var y = new Checker2();
+
+if (x < y || y < x || x <= y) {
+  assertEquals(3, x.valueOfCalled());
+  assertEquals(3, y.valueOfCalled());
+  assertEquals(1, (x < y) + (y < x) + (x <= y))
+  assertEquals(6, x.valueOfCalled());
+  assertEquals(6, y.valueOfCalled());
+  x < y;
+  assertEquals(7, x.valueOfCalled());
+  assertEquals(7, y.valueOfCalled());
+  x < y;
+  assertEquals(8, x.valueOfCalled());
+  assertEquals(8, y.valueOfCalled());
+  var res;
+  if (x <= y) {
+    res = 1+(x > {});
+  } else {
+    assertTrue(false);
+    res = y <= {};
+  }
+  assertEquals(10, x.valueOfCalled());
+  assertEquals(9, y.valueOfCalled());
+  assertEquals(1, res);
+  assertFalse(x < y);
+
+  var tb = 0, fb = 0;
+  var val = 0;
+  for (var i = 1; i < 10; i++) {
+    var res = 0;
+    // uses x,y in control context
+    if (x <= y) {
+      res += val;
+      assertTrue(x <= y);
+      // adds 1 + 0, uses x in value context
+      res += 1+(x > {});
+      tb++;
+      assertEquals(fb, tb);
+    } else {
+      res += val;
+      assertFalse(x < y);
+      // adds 1, uses y in value context, increments 2
+      res += (y <= y);
+      // use x in value context, increments x once to make it equal to y again
+      x + 2;
+      assertEquals(fb, tb);
+      fb++;
+    }
+    assertEquals(11+(2*i)+tb+fb, x.valueOfCalled());
+    assertEquals(10+(2*i)+(2*fb), y.valueOfCalled());
+    assertEquals(1 + val, res);
+    // Triggers deopt inside branch.
+    if (i%5 == 0) val += 0.5;
+  }
+} else {
+  assertTrue(false);
+}
+
+
+function t(a,b) { return (b < a) - (a < b); };
+function f() {
+  x = new Checker2();
+  y = new Checker2();
+  var tb = 0, fb = 0;
+  var val = 0;
+  for (var i = 1; i < 10; i++) {
+    var res = 0;
+    if ((x < y) + (y < x)) {
+      res += val;
+      res += x<0;
+      fb++;
+    } else {
+      res += val;
+      res += y<0;
+      tb++;
+    }
+    assertEquals(0, res + 1 - res - 1);
+    assertEquals((2*i)+fb, x.valueOfCalled());
+    assertEquals((2*i)+tb, y.valueOfCalled());
+    assertEquals(val, res);
+    if (i%4 == 0) val += 0.5;
+  }
+}
+
+f();
+%OptimizeFunctionOnNextCall(f);
+f();
+
+var a = {valueOf: function(){this.conv++; return 1;}};
+var b = {valueOf: function(){this.conv++; return 2;}};
+
+a.conv = 0;
+b.conv = 0;
+
+function f2(a,b,d1,d2) {
+  var runs = 0;
+  if ((a < b) + (a < b)) {
+    if (d2) { d2 += 0.2; }
+    runs++;
+  } else {
+    assertUnreachable();
+  }
+  assertEquals(1, runs);
+  if (a > b) {
+    assertUnreachable();
+  } else {
+    if (d1) { d1 += 0.2; }
+    runs++;
+  }
+  assertEquals(2, runs);
+}
+
+f2(a,b);
+f2(a,b);
+
+%OptimizeFunctionOnNextCall(f2);
+f2(a,b);
+f2(a,b);
+
+f2(a,b,true);
+f2(a,b);
+
+%OptimizeFunctionOnNextCall(f2);
+f2(a,b);
+f2(a,b);
+
+f2(a,b,false,true);
+f2(a,b);
+
+assertEquals(30, a.conv);
+assertEquals(30, b.conv);
+
+b.valueOf = function(){ return {}; }
+try {
+  f2(a,b);
+} catch(e) {
+  res = e.stack;
+}