test/bench: a couple fixes to timing.sh

- Skip the gccgo tests if we don't have it
- Add -lm so nbody.c will compile
- Pass 2098 to the meteor test (cf. the shootout site)

R=rsc, r, iant
CC=golang-dev
https://golang.org/cl/3619042

test/bench/timing.log

@@ -90,7 +90,7 @@ mandelbrot 5500
 	gc mandelbrot	74.32u 0.00s 74.35r
 	gc_B mandelbrot	74.28u 0.01s 74.31r
 
-meteor 16000
+meteor 2100
 	# we don't know
 	gcc -O2 meteor-contest.c	0.10u 0.00s 0.10r
 	gccgo -O2 meteor-contest.go	0.12u 0.00s 0.14r
@@ -209,7 +209,7 @@ mandelbrot 16000
 	gc mandelbrot	64.05u 0.02s 64.08r	# *** -14%
 	gc_B mandelbrot	64.10u 0.02s 64.14r	# *** -14%
 
-meteor 16000
+meteor 2100
 	# we don't know
 	gcc -O2 meteor-contest.c	0.10u 0.00s 0.10r
 	gccgo -O2 meteor-contest.go	0.12u 0.00s 0.12r
@@ -307,7 +307,7 @@ mandelbrot 16000
 	gc mandelbrot	63.31u 0.01s 63.35r	# -1%
 	gc_B mandelbrot	63.29u 0.00s 63.31r	# -1%
 
-meteor 16000
+meteor 2100
 	# we don't know
 	gcc -O2 meteor-contest.c	0.10u 0.00s 0.10r
 	gccgo -O2 meteor-contest.go	0.11u 0.00s 0.12r
@@ -477,7 +477,7 @@ mandelbrot 16000
 	gc mandelbrot	66.05u 0.00s 66.07r	# -3%
 	gc_B mandelbrot	66.06u 0.00s 66.07r	# -3%
 
-meteor 16000
+meteor 2100
 	gcc -O2 meteor-contest.c	0.10u 0.00s 0.10r
 	gccgo -O2 meteor-contest.go	0.12u 0.00s 0.12r
 	gc meteor-contest	0.17u 0.00s 0.17r
@@ -561,7 +561,7 @@ mandelbrot 16000
 	gc mandelbrot	64.85u 0.01s 64.94r
 	gc_B mandelbrot	65.02u 0.01s 65.14r
 
-meteor 16000
+meteor 2100
 	gcc -O2 meteor-contest.c	0.10u 0.00s 0.10r
 	gccgo -O2 meteor-contest.go	0.10u 0.00s 0.11r
 	gc meteor-contest	0.17u 0.00s 0.18r

test/bench/timing.sh

@@ -8,6 +8,12 @@ set -e
 eval $(gomake --no-print-directory -f ../../src/Make.inc go-env)
 PATH=.:$PATH
 
+havegccgo=false
+if which gccgo >/dev/null 2>&1
+then
+	havegccgo=true
+fi
+
 mode=run
 case X"$1" in
 X-test)
@@ -30,8 +36,6 @@ runonly() {
 	fi
 }
 
-
-
 run() {
 	if [ $mode = test ]
 	then
@@ -57,6 +61,10 @@ run() {
 		fi
 		return
 	fi
+	if ! $havegccgo && echo $1 | grep -q '^gccgo '
+	then
+		return
+	fi
 	echo -n '	'$1'	'
 	$1
 	shift
@@ -85,7 +93,7 @@ revcomp() {
 
 nbody() {
 	runonly echo 'nbody -n 50000000'
-	run 'gcc -O2 nbody.c' a.out 50000000
+	run 'gcc -O2 -lm nbody.c' a.out 50000000
 	run 'gccgo -O2 nbody.go' a.out -n 50000000
 	run 'gc nbody' $O.out -n 50000000
 	run 'gc_B nbody' $O.out -n 50000000
@@ -152,11 +160,11 @@ mandelbrot() {
 }
 
 meteor() {
-	runonly echo 'meteor 16000'
-	run 'gcc -O2 meteor-contest.c' a.out
-	run 'gccgo -O2 meteor-contest.go' a.out
-	run 'gc meteor-contest' $O.out
-	run 'gc_B  meteor-contest' $O.out
+	runonly echo 'meteor 2098'
+	run 'gcc -O2 meteor-contest.c' a.out 2098
+	run 'gccgo -O2 meteor-contest.go' a.out -n 2098
+	run 'gc meteor-contest' $O.out -n 2098
+	run 'gc_B  meteor-contest' $O.out -n 2098
 }
 
 pidigits() {