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 function foo()

 {

   // Range analysis incorrectly computes a range for the multiplication.  Once

   // that incorrect range is computed, the goal is to compute a new value whose

   // range analysis *thinks* is in int32_t range, but which goes past it using

   // JS semantics.

   //

   // On the final iteration, in JS semantics, the multiplication produces 0, and

   // the next addition 0x7fffffff.  Adding any positive integer to that goes

   // past int32_t range: here, (0x7fffffff + 5) or 2147483652.

   //

   // Range analysis instead thinks the multiplication produces a value in the

   // range [INT32_MIN, INT32_MIN], and the next addition a value in the range

   // [-1, -1].  Adding any positive value to that doesn't overflow int32_t range

   // but *does* overflow the actual range in JS semantics.  Thus omitting

   // overflow checks produces the value 0x80000004, which interpreting as signed

   // is (INT32_MIN + 4) or -2147483644.

   //

   // For this test to trigger the bug it was supposed to trigger:

   //

   //   * 0x7fffffff must be the LHS, not RHS, of the addition in the loop, and

   //   * i must not be incremented using ++

   //

   // The first is required because JM LoopState doesn't treat *both* V + mul and

   // mul + V as not overflowing, when V is known to be int32_t -- only V + mul.

   // (JM pessimally assumes V's type might change before it's evaluated.  This

   // obviously can't happen if V is a constant, but JM's puny little mind

   // doesn't detect this possibility now.)

   //

   // The second is required because JM LoopState only ignores integer overflow

   // on multiplications if the enclosing loop is a "constrainedLoop" (the name

   // of the relevant field).  Loops become unconstrained when unhandled ops are

   // found in the loop.  Increment operators generate a DUP op, which is not

   // presently a handled op, causing the loop to become unconstrained.

   for (var i = 0; i < 15; i = i + 1) {

     var y = (0x7fffffff + ((i & 1) * -2147483648)) + 5;

   }

   return y;

 }

 assertEq(foo(), (0x7fffffff + ((14 & 1) * -2147483648)) + 5);

 function bar()

 {

   // Variation on the theme of the above test with -1 as the other half of the

   // INT32_MIN multiplication, which *should* result in -INT32_MIN on multiply

   // (exceeding int32_t range).

   //

   // Here, range analysis again thinks the range of the multiplication is

   // INT32_MIN.  We'd overflow-check except that adding zero (on the LHS, see

   // above) prevents overflow checking, so range analysis thinks the range is

   // [INT32_MIN, INT32_MIN] when -INT32_MIN is actually possible.  This direct

   // result of the multiplication is already out of int32_t range, so no need to

   // add anything to bias it outside int32_t range to get a wrong result.

   for (var i = 0; i < 17; i = i + 1) {

     var y = (0 + ((-1 + (i & 1)) * -2147483648));

   }

   return y;

 }

 assertEq(bar(), (0 + ((-1 + (16 & 1)) * -2147483648)));