diff -r 000000000000 -r 6474c204b198 gfx/tests/process-textruns.pl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/tests/process-textruns.pl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,137 @@
+#!/usr/bin/perl -w
+
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# This script is a bunch of utilities for computing statistics about the textruns
+# created during a Gecko run.
+#
+# Usage:
+# 1) Uncomment #define DUMP_TEXT_RUNS in gfxAtsuiFonts.cpp
+# 2) Build
+# 3) Run over some test set, redirecting stdout to a file
+# 4) Pipe that file through this script
+
+# --exclude-spaces-only: ignore all textruns that consistent of zero or more
+# spaces
+my $exclude_spaces = grep(/^--exclude-spaces-only$/, @ARGV);
+
+# --dump-runs: process textruns into a format that can be used by
+# gfxTextRunPerfTest, print that on standard output, and do nothing else
+my $dump_runs = grep(/^--dump-runs$/, @ARGV);
+
+# --obfuscate: ROTL13 the textrun text
+my $obfuscate = grep(/^--obfuscate$/, @ARGV);
+
+my @textruns = ();
+
+while (<STDIN>) {
+  if (/^0x(\w+)\((.*)\) TEXTRUN "(.*)" ENDTEXTRUN$/) {
+    my %tr = ( fontgroup => $1,
+               families => $2,
+               text => $3 );
+    push(@textruns, \%tr);
+  } elsif (/^0x(\w+)\((.*)\) TEXTRUN "(.*)$/) {
+    my %tr = ( fontgroup => $1,
+               families => $2 );
+    my $text = $3."\n";
+    while (<STDIN>) {
+      if (/^(.*)" ENDTEXTRUN$/) {
+        $text .= $1;
+        last;
+      }
+      $text .= $_;
+    }
+    $tr{text} = $text;
+    push(@textruns, \%tr);
+  }
+}
+
+my %quote = ( "\\" => 1, "\"" => 1 );
+
+sub quote_str {
+    my ($text) = @_;
+    my @chars = split(//, $text);
+    my @strs = ();
+    foreach my $c (@chars) {
+      if (ord($c) >= 0x80) {
+        $c = "\\x".sprintf("%x",ord($c)).'""';
+      } elsif ($quote{$c}) {
+        $c = "\\$c";
+      } elsif ($c eq "\n") {
+        $c = " ";
+      }
+      push(@strs, $c);
+    }
+    return '"'.join("", @strs).'"';
+}
+
+if ($dump_runs) {
+  foreach my $tr (@textruns) {
+    print "{ ", &quote_str($tr->{families}), ",\n";
+    my $text = $tr->{text};
+    if ($obfuscate) {
+        $text =~ tr/a-mA-Mn-zN-Z/n-zN-Za-mA-M/;
+    }
+    print "  ", &quote_str($text), " },\n";
+  }
+  exit(0);
+}
+
+my %trs_by_text = ();
+my %trs_by_text_and_fontgroup = ();
+my %trs_by_trimmed_text_and_fontgroup = ();
+my @tr_lengths = ();
+
+$trs_by_text{" "} = [];
+$trs_by_text{""} = [];
+
+sub trim {
+  my ($s) = @_;
+  $s =~ s/^ *//g;
+  $s =~ s/ *$//g;
+  return $s;
+}
+
+my $total_textruns = 0;
+
+foreach my $tr (@textruns) {
+  if ($exclude_spaces && $tr->{text} =~ /^ *$/) {
+    next;
+  }
+  ++$total_textruns;
+  push(@{$trs_by_text{$tr->{text}}}, $tr);
+  push(@{$trs_by_text_and_fontgroup{$tr->{fontgroup}.$tr->{text}}}, $tr);
+  push(@{$trs_by_trimmed_text_and_fontgroup{$tr->{fontgroup}.&trim($tr->{text})}}, $tr);
+  if (1 < scalar(@{$trs_by_trimmed_text_and_fontgroup{$tr->{fontgroup}.&trim($tr->{text})}})) {
+    $tr_lengths[length($tr->{text})]++;
+  }
+}
+
+print "Number of textruns:\t$total_textruns\n";
+print "Number of textruns which are one space:\t", scalar(@{$trs_by_text{" "}}), "\n";
+print "Number of textruns which are empty:\t", scalar(@{$trs_by_text{""}}), "\n";
+
+my $count = 0;
+foreach my $k (keys(%trs_by_text)) {
+  if ($k =~ /^ *$/) {
+    $count += @{$trs_by_text{$k}};
+  }
+}
+print "Number of textruns which are zero or more spaces:\t$count\n";
+
+print "Number of unique textruns by text and fontgroup:\t", scalar(keys(%trs_by_text_and_fontgroup)), "\n";
+print "Number of unique textruns by trimmed text and fontgroup:\t", scalar(keys(%trs_by_trimmed_text_and_fontgroup)), "\n";
+
+my $sum = 0;
+my $weighted_sum = 0;
+if (1) {
+  print "Textrun length distribution:\n";
+  for my $i (0..(scalar(@tr_lengths)-1)) {
+    my $amount = defined($tr_lengths[$i])?$tr_lengths[$i]:0;
+    $sum += $amount;
+    $weighted_sum += $i*$amount;
+    print "$i\t$sum\t$weighted_sum\n";
+  }
+}