math/big: use run for benchmarks

shortens code and gives an example of the use of Run.

Change-Id: I75ffaf762218a589274b4b62e19022e31e805d1b
Reviewed-on: https://go-review.googlesource.com/23424Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/math/big/arith_test.go

@@ -5,6 +5,7 @@
 package big
 
 import (
+	"fmt"
 	"math/rand"
 	"testing"
 )
@@ -118,28 +119,36 @@ func rndV(n int) []Word {
 	return v
 }
 
-func benchmarkFunVV(b *testing.B, f funVV, n int) {
-	x := rndV(n)
-	y := rndV(n)
-	z := make([]Word, n)
-	b.SetBytes(int64(n * _W))
-	b.ResetTimer()
+var benchSizes = []struct {
+	name string
+	n    int
+}{
+	{"1", 1},
+	{"2", 2},
+	{"3", 3},
+	{"4", 4},
+	{"5", 5},
+	{"1e1", 1e1},
+	{"1e2", 1e2},
+	{"1e3", 1e3},
+	{"1e4", 1e4},
+	{"1e5", 1e5},
+}
+
+func BenchmarkAddVV(b *testing.B) {
+	for _, tc := range benchSizes {
+		x := rndV(tc.n)
+		y := rndV(tc.n)
+		z := make([]Word, tc.n)
+		b.Run(fmt.Sprint(tc.name), func(b *testing.B) {
+			b.SetBytes(int64(tc.n * _W))
 			for i := 0; i < b.N; i++ {
-		f(z, x, y)
+				addVV(z, x, y)
+			}
+		})
 	}
 }
 
-func BenchmarkAddVV_1(b *testing.B)   { benchmarkFunVV(b, addVV, 1) }
-func BenchmarkAddVV_2(b *testing.B)   { benchmarkFunVV(b, addVV, 2) }
-func BenchmarkAddVV_3(b *testing.B)   { benchmarkFunVV(b, addVV, 3) }
-func BenchmarkAddVV_4(b *testing.B)   { benchmarkFunVV(b, addVV, 4) }
-func BenchmarkAddVV_5(b *testing.B)   { benchmarkFunVV(b, addVV, 5) }
-func BenchmarkAddVV_1e1(b *testing.B) { benchmarkFunVV(b, addVV, 1e1) }
-func BenchmarkAddVV_1e2(b *testing.B) { benchmarkFunVV(b, addVV, 1e2) }
-func BenchmarkAddVV_1e3(b *testing.B) { benchmarkFunVV(b, addVV, 1e3) }
-func BenchmarkAddVV_1e4(b *testing.B) { benchmarkFunVV(b, addVV, 1e4) }
-func BenchmarkAddVV_1e5(b *testing.B) { benchmarkFunVV(b, addVV, 1e5) }
-
 type funVW func(z, x []Word, y Word) (c Word)
 type argVW struct {
 	z, x nat
@@ -236,28 +245,20 @@ func TestFunVW(t *testing.T) {
 	}
 }
 
-func benchmarkFunVW(b *testing.B, f funVW, n int) {
-	x := rndV(n)
+func BenchmarkAddVW(b *testing.B) {
+	for _, tc := range benchSizes {
+		x := rndV(tc.n)
 		y := rndW()
-	z := make([]Word, n)
-	b.SetBytes(int64(n * _S))
-	b.ResetTimer()
+		z := make([]Word, tc.n)
+		b.Run(fmt.Sprint(tc.name), func(b *testing.B) {
+			b.SetBytes(int64(tc.n * _S))
 			for i := 0; i < b.N; i++ {
-		f(z, x, y)
+				addVW(z, x, y)
+			}
+		})
 	}
 }
 
-func BenchmarkAddVW_1(b *testing.B)   { benchmarkFunVW(b, addVW, 1) }
-func BenchmarkAddVW_2(b *testing.B)   { benchmarkFunVW(b, addVW, 2) }
-func BenchmarkAddVW_3(b *testing.B)   { benchmarkFunVW(b, addVW, 3) }
-func BenchmarkAddVW_4(b *testing.B)   { benchmarkFunVW(b, addVW, 4) }
-func BenchmarkAddVW_5(b *testing.B)   { benchmarkFunVW(b, addVW, 5) }
-func BenchmarkAddVW_1e1(b *testing.B) { benchmarkFunVW(b, addVW, 1e1) }
-func BenchmarkAddVW_1e2(b *testing.B) { benchmarkFunVW(b, addVW, 1e2) }
-func BenchmarkAddVW_1e3(b *testing.B) { benchmarkFunVW(b, addVW, 1e3) }
-func BenchmarkAddVW_1e4(b *testing.B) { benchmarkFunVW(b, addVW, 1e4) }
-func BenchmarkAddVW_1e5(b *testing.B) { benchmarkFunVW(b, addVW, 1e5) }
-
 type funVWW func(z, x []Word, y, r Word) (c Word)
 type argVWW struct {
 	z, x nat
@@ -382,28 +383,20 @@ func TestMulAddWWW(t *testing.T) {
 	}
 }
 
-func benchmarkAddMulVVW(b *testing.B, n int) {
-	x := rndV(n)
+func BenchmarkAddMulVVW(b *testing.B) {
+	for _, tc := range benchSizes {
+		x := rndV(tc.n)
 		y := rndW()
-	z := make([]Word, n)
-	b.SetBytes(int64(n * _W))
-	b.ResetTimer()
+		z := make([]Word, tc.n)
+		b.Run(fmt.Sprint(tc.n), func(b *testing.B) {
+			b.SetBytes(int64(tc.n * _W))
 			for i := 0; i < b.N; i++ {
 				addMulVVW(z, x, y)
 			}
+		})
+	}
 }
 
-func BenchmarkAddMulVVW_1(b *testing.B)   { benchmarkAddMulVVW(b, 1) }
-func BenchmarkAddMulVVW_2(b *testing.B)   { benchmarkAddMulVVW(b, 2) }
-func BenchmarkAddMulVVW_3(b *testing.B)   { benchmarkAddMulVVW(b, 3) }
-func BenchmarkAddMulVVW_4(b *testing.B)   { benchmarkAddMulVVW(b, 4) }
-func BenchmarkAddMulVVW_5(b *testing.B)   { benchmarkAddMulVVW(b, 5) }
-func BenchmarkAddMulVVW_1e1(b *testing.B) { benchmarkAddMulVVW(b, 1e1) }
-func BenchmarkAddMulVVW_1e2(b *testing.B) { benchmarkAddMulVVW(b, 1e2) }
-func BenchmarkAddMulVVW_1e3(b *testing.B) { benchmarkAddMulVVW(b, 1e3) }
-func BenchmarkAddMulVVW_1e4(b *testing.B) { benchmarkAddMulVVW(b, 1e4) }
-func BenchmarkAddMulVVW_1e5(b *testing.B) { benchmarkAddMulVVW(b, 1e5) }
-
 func testWordBitLen(t *testing.T, fname string, f func(Word) int) {
 	for i := 0; i <= _W; i++ {
 		x := Word(1) << uint(i-1) // i == 0 => x == 0
@@ -420,23 +413,15 @@ func TestWordBitLen(t *testing.T) {
 }
 
 // runs b.N iterations of bitLen called on a Word containing (1 << nbits)-1.
-func benchmarkBitLenN(b *testing.B, nbits uint) {
+func BenchmarkBitLen(b *testing.B) {
+	// Individual bitLen tests. Numbers chosen to examine both sides
+	// of powers-of-two boundaries.
+	for _, nbits := range []uint{0, 1, 2, 3, 4, 5, 8, 9, 16, 17, 31} {
 		testword := Word((uint64(1) << nbits) - 1)
+		b.Run(fmt.Sprint(nbits), func(b *testing.B) {
 			for i := 0; i < b.N; i++ {
 				bitLen(testword)
 			}
+		})
+	}
 }
-
-// Individual bitLen tests. Numbers chosen to examine both sides
-// of powers-of-two boundaries.
-func BenchmarkBitLen0(b *testing.B)  { benchmarkBitLenN(b, 0) }
-func BenchmarkBitLen1(b *testing.B)  { benchmarkBitLenN(b, 1) }
-func BenchmarkBitLen2(b *testing.B)  { benchmarkBitLenN(b, 2) }
-func BenchmarkBitLen3(b *testing.B)  { benchmarkBitLenN(b, 3) }
-func BenchmarkBitLen4(b *testing.B)  { benchmarkBitLenN(b, 4) }
-func BenchmarkBitLen5(b *testing.B)  { benchmarkBitLenN(b, 5) }
-func BenchmarkBitLen8(b *testing.B)  { benchmarkBitLenN(b, 8) }
-func BenchmarkBitLen9(b *testing.B)  { benchmarkBitLenN(b, 9) }
-func BenchmarkBitLen16(b *testing.B) { benchmarkBitLenN(b, 16) }
-func BenchmarkBitLen17(b *testing.B) { benchmarkBitLenN(b, 17) }
-func BenchmarkBitLen31(b *testing.B) { benchmarkBitLenN(b, 31) }