Frog: compareTo can be made much faster

[rakudrama]

The attached test uses a.compareTo(b)

sh.dart is a Skew Heap.
sh_test.dart uses the heap.

time dart_bin sh_test.dart
real 0m0.145s
user 0m0.140s
sys 0m0.000s

time frogsh sh_test.dart (includes <1s compile time)
real 0m3.851s
user 0m3.810s
sys 0m0.020s

The problem appears to be that a.compareTo(b) boxes the number a.
It would be better to avoid the boxing, similar to how $add(x, y) is called to avoid boxing on non-resolved operator+.

I hacked output of Frog, changing the call a.compareTo(b) to $compareTo(a, b)

function $compareTo(a, b) {
  if (typeof a == 'number' && typeof b == 'number') {
    if (a < b) return -1;
    if (a > b) return 1;
    if (a != 0) return 0;
    var signA = 1/a;
    var signB = 1/b;
    if (signA < signB) return -1;
    if (signB < signA) return 1;
    return 0;
  }
  return a.compareTo(b);
}

The time changed to ~0.400s, i.e 10x faster.

A 'production quality' $compareTo should also special case string vs string.

Similar hacking on a program that uses List.sort((a, b) => a.compareTo(b)) yielded a 40x speedup.

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Attachments:
sh.dart (1001 Bytes)
sh_test.dart (1.43 KB)

[jmesserly]

IMO we should fix this for all native functions on String and num, with a uniform solution. If done correctly, it can even make a lot of the code cleaner. Most of the stubs in corejs.dart can go away, and instead become "native" methods on num.dart, String.dart again.

[DartBot]

This comment was originally written by jimhug@google.com

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SGTM!

[DartBot]

This comment was originally written by jimhug@google.com

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Marking as low pri as this would be okay to let slip until next quarter. Please edit the priority if you think this is critical to using frog in the near term.

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Removed Priority-Medium label.
Added Priority-Low label.

[jmesserly]

Fixed by switching to strict mode. Depending on what our browser target set is, we might need to add $compareTo, but this should leave us in good place for now.

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Added Fixed label.