js/landbranch.pl
author Steve Snyder <swsnyder@snydernet.net>
Thu, 01 Oct 2009 14:19:41 -0400
changeset 33346 8a43f01f1d6478ad072c1f4a41fb633f8a5e3a32
parent 1 9b2a99adc05e53cd4010de512f50118594756650
permissions -rwxr-xr-x
Bug 512865. qcms: Improve SSE2 performance, add SSE support. r=jrmuizel This patch greatly improves the performance of QCMS transformations on x86 & x86_64 systems. Some notes: 0. On 32-bit x86 systems it does runtime selection between non-SIMD, SSE, and SSE2 code paths. 1. On x86_64 systems the SSE2 code path is always taken. The non-SIMD and SSE code paths are left intact, but contemporary versions of the GCC and MSVC compilers will see that they cannot be reached and optimize them away. 2. The execution of the SSE2 code path is reduced by 67%, relative to the original Intel/Microsoft formatted ASM code. The relative performance is seen on a Pentium4 (Northwood) 2.4GHz CPU with DDR1 RAM. 3. The SSE code path provides a 80% reduction in execution time, relative to the non-SIMD code path. The relative performance is seen on a Pentium3 (Coppermine) 1.26GHz CPU with SDRAM. 4. The code has been split out into separate files so that it can be built with different cflags (-msse, and -msse2) when using gcc. 5. Try to land again, this time with __attribute__((__force_align_arg_pointer__)) to avoid crashes on linux.

#! /usr/local/bin/perl5

use File::Path;

# The development branch is where primary development and checkins
# are done on a day-to-day basis.
$development_branch_prefix = "SpiderMonkey140";

# Space-separated list of CVS-controlled directories to tag/merge
$merge_dirs =
    "mozilla/js/src " ;

# When line below uncommented, don't recurse into subdirs
#$recurse_flag = '-l';

#----------------------------------------------------------------------------

# The merge branch is itself a branch off of the development branch
# at a point where the development branch is thought to be stable.
# (A branch is used rather than a static tag because, inevitably,
# the development branch is not quite as stable/buildable as was
# thought.)  The contents of the merge branch will be copied to
# the trunk when merging takes place.


# The following tags are created automatically by this script:
#
# JS_STABLE_DROP
#
#     A static tag on the development branch (or a branch off the
#     development branch) that indicates the code that should be merged
#     into the trunk.  This is a "variable" tag in the sense that it is
#     redefined after each merge.
#
# JS_LAST_STABLE_DROP
#
#     A static tag that is a copy of what the JS_STABLE_DROP tag was in
#     the previous merge cycle.  This is a "variable" tag that is
#     redefined after each merge.  Changes in the branch can be merged
#     to the trunk by using:
#
#         cvs up -jJS_LAST_STABLE_DROP -jJS_STABLE_DROP
#
# JS_LANDING
#
#     A static tag that identifies the code on the trunk after the merge
#     from the branch to the trunk takes place.  This is a "variable"
#     tag that is redefined after each merge.  Changes on the trunk
#     since the last branch landing can be seen by using:
#
#         cvs diff -rJS_LANDING -rHEAD
#
# JS_LANDING_mmddyyyy
#
#     This is a tag on the trunk which may be used for archaeological
#     purposes.  This tag is made from the JS_LANDING tag.


$development_branch = $development_branch_prefix . "_BRANCH";
$development_base = $development_branch_prefix . "_BASE";

sub help {
print <<"END";
$0: A tool for merging stable snapshots of JavaScript from a CVS
development branch onto the trunk

Landing a snapshot of the development branch consists of
the following steps:

  1) Tag all/some files on the branch to identify files to be merged.
  2) Merge files from the branch into the trunk using a temporary
     working directory.
  3) Resolve any conflicts that arise as a result of the merge.
  4) Commit merged changes to the trunk.
  5) Make changes to resolve (build) difficulties and re-commit.
     Repeat as necessary.
  6) Backpropagate changes on the trunk to the development branch.
  
This script will assist with steps #2, #4 and #6:

  $0 -merge JS_STABLE_10131998
  $0 -commit
  $0 -backpatch
  
END
}

sub log {
    local($msg) = @_;
    print LOGFILE $msg if $logfile;
}

# Similar to die built-in
sub die {
    local($msg) = @_;
    &log($msg);
    chomp($msg);
    if ($logfile) {
	$msg .= "\nSee $logfile for details.";
    }
    die "$msg\n";
}

# Similar to system() built-in
sub system {
    local(@args) = @_;
    local($cmd) = join(" ", @args);
    &log("Executing: $cmd\n");

    if ($logfile) {
	$cmd .= " >> $logfile 2>&1";
	close(LOGFILE);
    }

    local($result) = 0xffff & system($cmd);

    if ($logfile) {
	open(LOGFILE, ">>$logfile");
    }

    return unless ($result);
    $msg = "Died while executing $cmd";

    if ($result == 0xff00) {
	&die("$msg\nWhile executExecution failed due to perl error: $!. ");
    } else {
	$result >>= 8;
	&die("$msg\nExecution failed; exit status: $result. ");
    }
}

chomp($root_dir = `pwd`);

# Default log file
$logfile = $root_dir . "/log";

while ($#ARGV >=0) {
    $_ = shift;
 
    if (/-merge/) {
	$do_tag = 1;
	$do_checkout = 1;
	$do_merge = 1;
	$tag = shift;
    } elsif (/-commit/ || /-ci/) {
	$do_commit = 1;
    } elsif (/-backpatch/) {
	$do_backpatch = 1;
    } elsif (/-log/) {
	$logfile = shift;
    } elsif (/-tag/) { # Debugging option
	$do_tag = 1;
	$tag = shift;
    } elsif (/-co/) {  # Debugging option
	$do_checkout = 1;
    } else {
	print STDERR "Illegal option: $_\n" unless (/-h/);
	&help();
	exit(1);
    }
}

die "You must set your CVSROOT environment variable" if !$ENV{"CVSROOT"};

if ($logfile) {
    open(LOGFILE, ">$logfile") || die "Couldn't open log file \"$logfile\"";
    print("Logging to file \"$logfile\".\n");
}

$trunk_dir = $root_dir . "/trunk";

if ($do_tag) {
    if (!$tag) {
	&die("Must specify tag on command-line\n");
    }

    print("Tagging tree with tag JS_STABLE_DROP.\n");
    &system("cvs rtag $recurse_flag -F -r $tag JS_STABLE_DROP $merge_dirs");
}

if ($do_checkout) {

    # Delete trunk subdir if it already exists
    if (-d $trunk_dir) {
	&log("Deleting directory $trunk_dir\n");
	rmtree ($trunk_dir, 0, 1);
    }
    &log("Creating directory $trunk_dir\n");
    mkdir($trunk_dir, 0777) || die "Couldn't create directory $trunk_dir";

    # Check out on trunk
    print("Checking out $merge_dirs.\n");
    chdir $trunk_dir;
    &system("cvs co $recurse_flag -A $merge_dirs");
}

if ($do_merge) {
    chdir $trunk_dir;
    print("Merging from JS_STABLE_DROP into trunk\n");
    &system("cvs up -jJS_LAST_STABLE_DROP -jJS_STABLE_DROP");
}

if ($do_commit) {
    &die("No merged tree found.  Wrong directory ?") if (!chdir $trunk_dir);

    ($_,$_,$_,$day,$mon,$year,$_,$_) = localtime(time());
    if ($year < 30) {
	$year = "20" . $year;
    } else {
	$year = "19" . $year;
    }

    $mmddyyyy = sprintf("%02d%02d%s", $mon, $day, $year);

    print("Checking in code on trunk");
    &system("cvs ci -m 'Stable drop of JavaScript interpreter code from " .
	    "$development_branch'");

    # Tag merged result
    &system("cvs tag -F JS_LANDING");
    &system("cvs tag -F JS_LANDING_$mmddyyyy");

    # Move JS_LAST_STABLE_DROP tag forward
    &system("cvs tag -F -rJS_STABLE_DROP JS_LAST_STABLE_DROP");
}