580051 - TABLESWITCH can be confused by fatvals

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jason Orendorff [:jorendorff]]

The implementation of TABLESWITCH assumes there are no integer-valued double Values, which isn't true anymore. Easy enough to fix.

var a = Math.sin(Math.PI/2);
assertEq(a, 1);
switch (a) {
  case 1: break;
  default: throw "FAIL";
}

(It would be nice to find a way to test this that doesn't involve inexact math, but this is the first way I found to trigger the bug.)

Comment 1

[Luke Wagner [:luke]]

Attachment: fix

Thanks Jason!

Comment 2

[Jason Orendorff [:jorendorff]]

Comment on attachment 458480 [details] [diff] [review]
fix

It seems the local variable d is unnecessary.

Please change the test to say this:

  var a = Math.sin(Math.PI/2);  // spec does not specify precise answer here...
  if (a === 1) {    // ...but if a === 1 here...
      switch (a) {
        case 1: break;  // ...then it must also match here
        default: throw "FAIL";
      }
  }

and add a second test like this:

  var arr = Float32Array(1);
  arr[0] = 15;
  var a = arr[0];
  assertEq(a, 15);
  switch (a) {
    case 15: break;
    default: throw "FAIL";
  }

r=me with that.

Comment 3

[Luke Wagner [:luke]]

http://hg.mozilla.org/tracemonkey/rev/73922e37b733

Comment 4

[Robert Sayre]

http://hg.mozilla.org/mozilla-central/rev/73922e37b733