Revert "tighten invariants of HValue::InferRange"

test/mjsunit/math-floor.js

 // Copyright 2011 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
@@ skipping 33 matching lines @@
 }
 
 function test() {
   testFloor(0, 0);
   testFloor(0, zero());
   testFloor(-0, -0);
   testFloor(Infinity, Infinity);
   testFloor(-Infinity, -Infinity);
   testFloor(NaN, NaN);
 
-  // Ensure that a negative zero coming from Math.floor is properly handled
-  // by other operations.
-  function ifloor(x) {
-    return 1 / Math.floor(x);
-  }
-  assertEquals(-Infinity, ifloor(-0));
-  assertEquals(-Infinity, ifloor(-0));
-  assertEquals(-Infinity, ifloor(-0));
-  %OptimizeFunctionOnNextCall(ifloor);
-  assertEquals(-Infinity, ifloor(-0));
-
   testFloor(0, 0.1);
   testFloor(0, 0.49999999999999994);
   testFloor(0, 0.5);
   testFloor(0, 0.7);
   testFloor(-1, -0.1);
   testFloor(-1, -0.49999999999999994);
   testFloor(-1, -0.5);
   testFloor(-1, -0.7);
   testFloor(1, 1);
   testFloor(1, 1.1);
@@ skipping 58 matching lines @@
   testFloor(-two_52 + 1, -two_52 + 1 + 0.1);
   testFloor(-two_52 + 1, -two_52 + 1 + 0.5);
   testFloor(-two_52 + 1, -two_52 + 1 + 0.7);
 }
 
 
 // Test in a loop to cover the custom IC and GC-related issues.
 for (var i = 0; i < 500; i++) {
   test();
 }
-
-
-// Regression test for a bug where a negative zero coming from Math.floor
-// was not properly handled by other operations.
-function floorsum(i, n) {
-  var ret = Math.floor(n);
-  while (--i > 0) {
-    ret += Math.floor(n);
-  }
-  return ret;
-}
-assertEquals(-0, floorsum(1, -0));
-%OptimizeFunctionOnNextCall(floorsum);
-// The optimized function will deopt.  Run it with enough iterations to try
-// to optimize via OSR (triggering the bug).
-assertEquals(-0, floorsum(100000, -0));