sort: deduplicate inner loop of Stable
benchmark old ns/op new ns/op delta
BenchmarkStableInt1K 117212 116287 -0.79%
BenchmarkStableInt64K 9632002 9587872 -0.46%
BenchmarkStable1e4 40044309 39865644 -0.45%
BenchmarkStable1e2 126985 126456 -0.42%
BenchmarkStableString1K 389774 391052 +0.33%
BenchmarkStable1e6 8183202516 8157693442 -0.31%
Change-Id: I14e518ad49ecce3d1fc2b056e1acd5e5a2de8144
Reviewed-on: https://go-review.googlesource.com/1821
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/sort/sort.go b/src/sort/sort.go
index e980c29..63f8894 100644
--- a/src/sort/sort.go
+++ b/src/sort/sort.go
@@ -359,30 +359,25 @@
mid := a + (b-a)/2
n := mid + m
- start := 0
+ var start, r int
if m > mid {
start = n - b
- r, p := mid, n-1
- for start < r {
- c := start + (r-start)/2
- if !data.Less(p-c, c) {
- start = c + 1
- } else {
- r = c
- }
- }
+ r = mid
} else {
start = a
- r, p := m, n-1
- for start < r {
- c := start + (r-start)/2
- if !data.Less(p-c, c) {
- start = c + 1
- } else {
- r = c
- }
+ r = m
+ }
+ p := n - 1
+
+ for start < r {
+ c := start + (r-start)/2
+ if !data.Less(p-c, c) {
+ start = c + 1
+ } else {
+ r = c
}
}
+
end := n - start
rotate(data, start, m, end)
symMerge(data, a, start, mid)
