remove unused functions

sort.go

@@ -329,158 +329,6 @@ func reverseRangeOrdered(data []rune, a, b int) {
 	}
 }
 
-func swapRangeOrdered(data []rune, a, b, n int) {
-	for i := 0; i < n; i++ {
-		data[a+i], data[b+i] = data[b+i], data[a+i]
-	}
-}
-
-func stableOrdered(data []rune, n int) {
-	blockSize := 20 // must be > 0
-	a, b := 0, blockSize
-	for b <= n {
-		insertionSortOrdered(data, a, b)
-		a = b
-		b += blockSize
-	}
-	insertionSortOrdered(data, a, n)
-
-	for blockSize < n {
-		a, b = 0, 2*blockSize
-		for b <= n {
-			symMergeOrdered(data, a, a+blockSize, b)
-			a = b
-			b += 2 * blockSize
-		}
-		if m := a + blockSize; m < n {
-			symMergeOrdered(data, a, m, n)
-		}
-		blockSize *= 2
-	}
-}
-
-// symMergeOrdered merges the two sorted subsequences data[a:m] and data[m:b] using
-// the SymMerge algorithm from Pok-Son Kim and Arne Kutzner, "Stable Minimum
-// Storage Merging by Symmetric Comparisons", in Susanne Albers and Tomasz
-// Radzik, editors, Algorithms - ESA 2004, volume 3221 of Lecture Notes in
-// Computer Science, pages 714-723. Springer, 2004.
-//
-// Let M = m-a and N = b-n. Wolog M < N.
-// The recursion depth is bound by ceil(log(N+M)).
-// The algorithm needs O(M*log(N/M + 1)) calls to data.Less.
-// The algorithm needs O((M+N)*log(M)) calls to data.Swap.
-//
-// The paper gives O((M+N)*log(M)) as the number of assignments assuming a
-// rotation algorithm which uses O(M+N+gcd(M+N)) assignments. The argumentation
-// in the paper carries through for Swap operations, especially as the block
-// swapping rotate uses only O(M+N) Swaps.
-//
-// symMerge assumes non-degenerate arguments: a < m && m < b.
-// Having the caller check this condition eliminates many leaf recursion calls,
-// which improves performance.
-func symMergeOrdered(data []rune, a, m, b int) {
-	// Avoid unnecessary recursions of symMerge
-	// by direct insertion of data[a] into data[m:b]
-	// if data[a:m] only contains one element.
-	if m-a == 1 {
-		// Use binary search to find the lowest index i
-		// such that data[i] >= data[a] for m <= i < b.
-		// Exit the search loop with i == b in case no such index exists.
-		i := m
-		j := b
-		for i < j {
-			h := int(uint(i+j) >> 1)
-			if data[h] < data[a] {
-				i = h + 1
-			} else {
-				j = h
-			}
-		}
-		// Swap values until data[a] reaches the position before i.
-		for k := a; k < i-1; k++ {
-			data[k], data[k+1] = data[k+1], data[k]
-		}
-		return
-	}
-
-	// Avoid unnecessary recursions of symMerge
-	// by direct insertion of data[m] into data[a:m]
-	// if data[m:b] only contains one element.
-	if b-m == 1 {
-		// Use binary search to find the lowest index i
-		// such that data[i] > data[m] for a <= i < m.
-		// Exit the search loop with i == m in case no such index exists.
-		i := a
-		j := m
-		for i < j {
-			h := int(uint(i+j) >> 1)
-			if data[h] < data[m] {
-				i = h + 1
-			} else {
-				j = h
-			}
-		}
-		// Swap values until data[m] reaches the position i.
-		for k := m; k > i; k-- {
-			data[k], data[k-1] = data[k-1], data[k]
-		}
-		return
-	}
-
-	mid := int(uint(a+b) >> 1)
-	n := mid + m
-	var start, r int
-	if m > mid {
-		start = n - b
-		r = mid
-	} else {
-		start = a
-		r = m
-	}
-	p := n - 1
-
-	for start < r {
-		c := int(uint(start+r) >> 1)
-		if data[c] < data[p-c] {
-			start = c + 1
-		} else {
-			r = c
-		}
-	}
-
-	end := n - start
-	if start < m && m < end {
-		rotateOrdered(data, start, m, end)
-	}
-	if a < start && start < mid {
-		symMergeOrdered(data, a, start, mid)
-	}
-	if mid < end && end < b {
-		symMergeOrdered(data, mid, end, b)
-	}
-}
-
-// rotateOrdered rotates two consecutive blocks u = data[a:m] and v = data[m:b] in data:
-// Data of the form 'x u v y' is changed to 'x v u y'.
-// rotate performs at most b-a many calls to data.Swap,
-// and it assumes non-degenerate arguments: a < m && m < b.
-func rotateOrdered(data []rune, a, m, b int) {
-	i := m - a
-	j := b - m
-
-	for i != j {
-		if i > j {
-			swapRangeOrdered(data, m-i, m, j)
-			i -= j
-		} else {
-			swapRangeOrdered(data, m-i, m+j-i, i)
-			j -= i
-		}
-	}
-	// i == j
-	swapRangeOrdered(data, m-i, m, i)
-}
-
 type sortedHint int // hint for pdqsort when choosing the pivot
 
 const (