math: remove Nextafter64 alias in favor of existing Nextafter

LGTM=adonovan
R=rsc, adonovan
CC=golang-codereviews
https://golang.org/cl/104050045

src/pkg/math/all_test.go

@@ -2356,12 +2356,12 @@ func TestNextafter32(t *testing.T) {
 
 func TestNextafter64(t *testing.T) {
 	for i := 0; i < len(vf); i++ {
-		if f := Nextafter64(vf[i], 10); nextafter64[i] != f {
+		if f := Nextafter(vf[i], 10); nextafter64[i] != f {
 			t.Errorf("Nextafter64(%g, %g) = %g want %g", vf[i], 10.0, f, nextafter64[i])
 		}
 	}
 	for i := 0; i < len(vfnextafter64SC); i++ {
-		if f := Nextafter64(vfnextafter64SC[i][0], vfnextafter64SC[i][1]); !alike(nextafter64SC[i], f) {
+		if f := Nextafter(vfnextafter64SC[i][0], vfnextafter64SC[i][1]); !alike(nextafter64SC[i], f) {
 			t.Errorf("Nextafter64(%g, %g) = %g want %g", vfnextafter64SC[i][0], vfnextafter64SC[i][1], f, nextafter64SC[i])
 		}
 	}
@@ -2886,7 +2886,7 @@ func BenchmarkNextafter32(b *testing.B) {
 
 func BenchmarkNextafter64(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Nextafter64(.5, 1)
+		Nextafter(.5, 1)
 	}
 }
 

src/pkg/math/big/rat_test.go

@@ -760,7 +760,7 @@ var float64inputs = []string{
 	"22.222222222222222",
 	"long:2." + strings.Repeat("2", 4000) + "e+1",
 
-	// Exactly halfway between 1 and math.Nextafter64(1, 2).
+	// Exactly halfway between 1 and math.Nextafter(1, 2).
 	// Round to even (down).
 	"1.00000000000000011102230246251565404236316680908203125",
 	// Slightly lower; still round down.
@@ -1103,8 +1103,8 @@ func checkIsBestApprox64(t *testing.T, f float64, r *Rat) bool {
 	}
 
 	// r must be strictly between f0 and f1, the floats bracketing f.
-	f0 := math.Nextafter64(f, math.Inf(-1))
-	f1 := math.Nextafter64(f, math.Inf(+1))
+	f0 := math.Nextafter(f, math.Inf(-1))
+	f1 := math.Nextafter(f, math.Inf(+1))
 
 	// For f to be correct, r must be closer to f than to f0 or f1.
 	df := delta(r, f)

src/pkg/math/nextafter.go

@@ -25,12 +25,12 @@ func Nextafter32(x, y float32) (r float32) {
 	return
 }
 
-// Nextafter64 returns the next representable float64 value after x towards y.
+// Nextafter returns the next representable float64 value after x towards y.
 // Special cases:
 //	Nextafter64(x, x)   = x
 //      Nextafter64(NaN, y) = NaN
 //      Nextafter64(x, NaN) = NaN
-func Nextafter64(x, y float64) (r float64) {
+func Nextafter(x, y float64) (r float64) {
 	switch {
 	case IsNaN(x) || IsNaN(y): // special case
 		r = NaN()
@@ -45,9 +45,3 @@ func Nextafter64(x, y float64) (r float64) {
 	}
 	return
 }
-
-// Nextafter is the same as Nextafter64.
-// It is provided for backward-compatibility only.
-func Nextafter(x, y float64) float64 {
-	return Nextafter64(x, y)
-}