runtime: implement string ops in Go
Also implement go:nosplit annotation. Not really needed
for now, but we'll definitely need it for other conversions.
benchmark old ns/op new ns/op delta
BenchmarkRuneIterate 534 474 -11.24%
BenchmarkRuneIterate2 535 470 -12.15%
LGTM=bradfitz
R=golang-codereviews, dave, bradfitz, minux
CC=golang-codereviews
https://golang.org/cl/93380044
diff --git a/src/pkg/runtime/string_test.go b/src/pkg/runtime/string_test.go
index df3ff06..dbccc24 100644
--- a/src/pkg/runtime/string_test.go
+++ b/src/pkg/runtime/string_test.go
@@ -75,3 +75,27 @@
}
b.SetBytes(int64(len(s1)))
}
+
+func BenchmarkRuneIterate(b *testing.B) {
+ bytes := make([]byte, 100)
+ for i := range bytes {
+ bytes[i] = byte('A')
+ }
+ s := string(bytes)
+ for i := 0; i < b.N; i++ {
+ for _ = range s {
+ }
+ }
+}
+
+func BenchmarkRuneIterate2(b *testing.B) {
+ bytes := make([]byte, 100)
+ for i := range bytes {
+ bytes[i] = byte('A')
+ }
+ s := string(bytes)
+ for i := 0; i < b.N; i++ {
+ for _, _ = range s {
+ }
+ }
+}
