#!perl -w
#
use Time::HiRes qw(time);

print "<table border>\n<tr><td>", join("</td><td>", "x", "y", "andNeg(
+)", "spaceship()", "mult()", "anchor()"), "</td></tr>\n";
for (0..3) {
  my $x = 1 - 2 * ($_ % 2);
  my $y = 1 - 2 * int($_ / 2);
  print "<tr><td>", join("</td><td>", $x, $y, andNeg($x, $y), spaceshi
+p($x, $y), mult($x, $y), anchor($x, $y)), "</td></tr>\n";
}
print "</table>\n";

my $count = 1000000;
for ('unit square', 'signed int') {
  doTimeTest($count, $_);
}
sub doTimeTest {
  my $count = shift;
  my $type = shift;

  my @coordinates = primeCoordinates($count, $type );
  my $time0 = Time::HiRes::time();
  foreach (@coordinates) {
    spaceship($_->[0],$_->[1]);
  }
  my $time1 = Time::HiRes::time();

  foreach (@coordinates) {
    mult($_->[0], $_->[1]);
  }
  my $time2 = Time::HiRes::time();

  foreach (@coordinates) {
    anchor($_->[0], $_->[1]);
  }

  my $time3 = Time::HiRes::time;

  my $spaceship = $time1 - $time0;
  my $multiple = $time2 - $time1;
  my $logic = $time3 - $time2;
  print join("\t", $type, "spaceship", "multiply", "logic"), "\n";
  print join("\t", "spaceship", '-'x8, pretty($spaceship,$multiple), p
+retty($spaceship,$logic)), "\n";
  print join("\t", "multiply ", pretty($multiple,$spaceship), '-'x8, p
+retty($multiple,$logic)), "\n";
  print join("\t", "logic    ", pretty($logic,$spaceship), pretty($log
+ic,$multiple), '-'x8), "\n";
  print "\n";
}

sub pretty {
  my ($one, $two) = @_;
  if ($one > $two) {
    return sprintf("worse %.2f%%", ($one - $two) / $one * 100);
  } else {
    return sprintf("better %.2f%%", ($two - $one) / $two * 100);
  }
}

sub spaceship {
  (0 <=> $_[0]) == (0<=> $_[1]);
}

sub mult {
  $_[0]*$_[1] > 0;
}

sub anchor {
  if ($_[0] > 0) {
    if ($_[1] > 0) { # both pos
      return 1
    }
  } elsif ($_[0] < 0) {
    if ($_[1] < 0) { # both neg
      return 1
    }
  }
  return 0;
}

sub andNeg {
  return (($_[0]^$_[1]) < 0);
}

sub primeCoordinates {
  my $count = shift;
  my $type = shift;
  my @retval;
  if ($type eq 'unit square') {
    for (0..$count-1) {
      $retval[$_] = [ 1 - 2 * rand(), 1 - 2 * rand()];
    }
  } elsif ($type eq 'signed int') {
    use POSIX;
    for (0..$count-1) {
      $retval[$_] = [ rand() > 0.5 ? rand(INT_MAX) : -1 * rand(INT_MAX
+),
                      rand() > 0.5 ? rand(INT_MAX) : -1 * rand(INT_MAX
+)];
    }
  } else {
    die "Blue.  No yel--  Auuuuuuuugh!\n";
  }
  return @retval;
}
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