math: add Exp2; 386 FPU versions of Exp2 and Log1p
Added tests and benchmarks for Exp2 (special cases same
as Exp). Log1p also enhances speed of inverse hyperbolics.
R=rsc
CC=golang-dev
https://golang.org/cl/206058
diff --git a/src/pkg/math/all_test.go b/src/pkg/math/all_test.go
index 8c47fd1..bd1d400 100644
--- a/src/pkg/math/all_test.go
+++ b/src/pkg/math/all_test.go
@@ -208,6 +208,18 @@
1.842068661871398836913874273e-02,
-8.3193870863553801814961137573e-02,
}
+var exp2 = []float64{
+ 3.1537839463286288034313104e+01,
+ 2.1361549283756232296144849e+02,
+ 8.2537402562185562902577219e-01,
+ 3.1021158628740294833424229e-02,
+ 7.9581744110252191462569661e+02,
+ 7.6019905892596359262696423e+00,
+ 3.7506882048388096973183084e+01,
+ 6.6250893439173561733216375e+00,
+ 3.5438267900243941544605339e+00,
+ 2.4281533133513300984289196e-03,
+}
var fdim = []float64{
4.9790119248836735e+00,
7.7388724745781045e+00,
@@ -1078,6 +1090,19 @@
}
}
+func TestExp2(t *testing.T) {
+ for i := 0; i < len(vf); i++ {
+ if f := Exp2(vf[i]); !close(exp2[i], f) {
+ t.Errorf("Exp2(%g) = %g, want %g\n", vf[i], f, exp2[i])
+ }
+ }
+ for i := 0; i < len(vfexpSC); i++ {
+ if f := Exp2(vfexpSC[i]); !alike(expSC[i], f) {
+ t.Errorf("Exp2(%g) = %g, want %g\n", vfexpSC[i], f, expSC[i])
+ }
+ }
+}
+
func TestFdim(t *testing.T) {
for i := 0; i < len(vf); i++ {
if f := Fdim(vf[i], 0); fdim[i] != f {
@@ -1492,6 +1517,12 @@
}
}
+func BenchmarkExp2(b *testing.B) {
+ for i := 0; i < b.N; i++ {
+ Exp(.5)
+ }
+}
+
func BenchmarkFloor(b *testing.B) {
for i := 0; i < b.N; i++ {
Floor(.5)
