Improvments to vg_perf:
- show percentage speedup over the first Valgrind when comparing multiple
Valgrind
- don't accept --reps < 0
- avoid div-by-zero if the runtime is measured as zero
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@5348 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/perf/vg_perf.in b/perf/vg_perf.in
index 2e4b352..887cc96 100644
--- a/perf/vg_perf.in
+++ b/perf/vg_perf.in
@@ -153,6 +153,7 @@
$alldirs = 1;
} elsif ($arg =~ /^--reps=(\d+)$/) {
$n_reps = $1;
+ if ($n_reps < 1) { die "bad --reps value: $n_reps\n"; }
} elsif ($arg =~ /^--vg=(.+)$/) {
# Make dir absolute if not already
add_vgdir($1);
@@ -255,7 +256,8 @@
die "\n*** missing usertime in perf.stderr\n";
$tmin = $1 if ($1 < $tmin);
}
- return $tmin;
+ # Avoid divisions by zero!
+ return (0 == $tmin ? 0.01 : $tmin);
}
sub do_one_test($$)
@@ -263,6 +265,8 @@
my ($dir, $vgperf) = @_;
$vgperf =~ /^(.*)\.vgperf/;
my $name = $1;
+ my %first_tTool; # For doing percentage speedups when comparing
+ # multiple Valgrinds
read_vgperf_file($vgperf);
@@ -307,7 +311,19 @@
. "$vgopts ";
my $cmd = "$vgsetup $timecmd $vgcmd $prog $args";
my $tTool = time_prog($cmd, $n_reps);
- printf("%4.1fs (%4.1fx) ", $tTool, $tTool/$tNative);
+ printf("%4.1fs (%4.1fx,", $tTool, $tTool/$tNative);
+
+ # If it's the first timing for this tool on this benchmark,
+ # record the time so we can get the percentage speedup of the
+ # subsequent Valgrinds. Otherwise, compute and print
+ # the speedup.
+ if (not defined $first_tTool{$tool}) {
+ $first_tTool{$tool} = $tTool;
+ print(" -----) ");
+ } else {
+ my $speedup = 100 - (100 * $tTool / $first_tTool{$tool});
+ printf("%5.1f%%) ", $speedup);
+ }
$num_timings_done++;