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-rw-r--r--fs/bcachefs/eytzinger.c315
1 files changed, 0 insertions, 315 deletions
diff --git a/fs/bcachefs/eytzinger.c b/fs/bcachefs/eytzinger.c
deleted file mode 100644
index 0e742555cb0a..000000000000
--- a/fs/bcachefs/eytzinger.c
+++ /dev/null
@@ -1,315 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-#include "eytzinger.h"
-
-/**
- * is_aligned - is this pointer & size okay for word-wide copying?
- * @base: pointer to data
- * @size: size of each element
- * @align: required alignment (typically 4 or 8)
- *
- * Returns true if elements can be copied using word loads and stores.
- * The size must be a multiple of the alignment, and the base address must
- * be if we do not have CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS.
- *
- * For some reason, gcc doesn't know to optimize "if (a & mask || b & mask)"
- * to "if ((a | b) & mask)", so we do that by hand.
- */
-__attribute_const__ __always_inline
-static bool is_aligned(const void *base, size_t size, unsigned char align)
-{
- unsigned char lsbits = (unsigned char)size;
-
- (void)base;
-#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
- lsbits |= (unsigned char)(uintptr_t)base;
-#endif
- return (lsbits & (align - 1)) == 0;
-}
-
-/**
- * swap_words_32 - swap two elements in 32-bit chunks
- * @a: pointer to the first element to swap
- * @b: pointer to the second element to swap
- * @n: element size (must be a multiple of 4)
- *
- * Exchange the two objects in memory. This exploits base+index addressing,
- * which basically all CPUs have, to minimize loop overhead computations.
- *
- * For some reason, on x86 gcc 7.3.0 adds a redundant test of n at the
- * bottom of the loop, even though the zero flag is still valid from the
- * subtract (since the intervening mov instructions don't alter the flags).
- * Gcc 8.1.0 doesn't have that problem.
- */
-static void swap_words_32(void *a, void *b, size_t n)
-{
- do {
- u32 t = *(u32 *)(a + (n -= 4));
- *(u32 *)(a + n) = *(u32 *)(b + n);
- *(u32 *)(b + n) = t;
- } while (n);
-}
-
-/**
- * swap_words_64 - swap two elements in 64-bit chunks
- * @a: pointer to the first element to swap
- * @b: pointer to the second element to swap
- * @n: element size (must be a multiple of 8)
- *
- * Exchange the two objects in memory. This exploits base+index
- * addressing, which basically all CPUs have, to minimize loop overhead
- * computations.
- *
- * We'd like to use 64-bit loads if possible. If they're not, emulating
- * one requires base+index+4 addressing which x86 has but most other
- * processors do not. If CONFIG_64BIT, we definitely have 64-bit loads,
- * but it's possible to have 64-bit loads without 64-bit pointers (e.g.
- * x32 ABI). Are there any cases the kernel needs to worry about?
- */
-static void swap_words_64(void *a, void *b, size_t n)
-{
- do {
-#ifdef CONFIG_64BIT
- u64 t = *(u64 *)(a + (n -= 8));
- *(u64 *)(a + n) = *(u64 *)(b + n);
- *(u64 *)(b + n) = t;
-#else
- /* Use two 32-bit transfers to avoid base+index+4 addressing */
- u32 t = *(u32 *)(a + (n -= 4));
- *(u32 *)(a + n) = *(u32 *)(b + n);
- *(u32 *)(b + n) = t;
-
- t = *(u32 *)(a + (n -= 4));
- *(u32 *)(a + n) = *(u32 *)(b + n);
- *(u32 *)(b + n) = t;
-#endif
- } while (n);
-}
-
-/**
- * swap_bytes - swap two elements a byte at a time
- * @a: pointer to the first element to swap
- * @b: pointer to the second element to swap
- * @n: element size
- *
- * This is the fallback if alignment doesn't allow using larger chunks.
- */
-static void swap_bytes(void *a, void *b, size_t n)
-{
- do {
- char t = ((char *)a)[--n];
- ((char *)a)[n] = ((char *)b)[n];
- ((char *)b)[n] = t;
- } while (n);
-}
-
-/*
- * The values are arbitrary as long as they can't be confused with
- * a pointer, but small integers make for the smallest compare
- * instructions.
- */
-#define SWAP_WORDS_64 (swap_r_func_t)0
-#define SWAP_WORDS_32 (swap_r_func_t)1
-#define SWAP_BYTES (swap_r_func_t)2
-#define SWAP_WRAPPER (swap_r_func_t)3
-
-struct wrapper {
- cmp_func_t cmp;
- swap_func_t swap_func;
-};
-
-/*
- * The function pointer is last to make tail calls most efficient if the
- * compiler decides not to inline this function.
- */
-static void do_swap(void *a, void *b, size_t size, swap_r_func_t swap_func, const void *priv)
-{
- if (swap_func == SWAP_WRAPPER) {
- ((const struct wrapper *)priv)->swap_func(a, b, (int)size);
- return;
- }
-
- if (swap_func == SWAP_WORDS_64)
- swap_words_64(a, b, size);
- else if (swap_func == SWAP_WORDS_32)
- swap_words_32(a, b, size);
- else if (swap_func == SWAP_BYTES)
- swap_bytes(a, b, size);
- else
- swap_func(a, b, (int)size, priv);
-}
-
-#define _CMP_WRAPPER ((cmp_r_func_t)0L)
-
-static int do_cmp(const void *a, const void *b, cmp_r_func_t cmp, const void *priv)
-{
- if (cmp == _CMP_WRAPPER)
- return ((const struct wrapper *)priv)->cmp(a, b);
- return cmp(a, b, priv);
-}
-
-static inline int eytzinger1_do_cmp(void *base1, size_t n, size_t size,
- cmp_r_func_t cmp_func, const void *priv,
- size_t l, size_t r)
-{
- return do_cmp(base1 + inorder_to_eytzinger1(l, n) * size,
- base1 + inorder_to_eytzinger1(r, n) * size,
- cmp_func, priv);
-}
-
-static inline void eytzinger1_do_swap(void *base1, size_t n, size_t size,
- swap_r_func_t swap_func, const void *priv,
- size_t l, size_t r)
-{
- do_swap(base1 + inorder_to_eytzinger1(l, n) * size,
- base1 + inorder_to_eytzinger1(r, n) * size,
- size, swap_func, priv);
-}
-
-static void eytzinger1_sort_r(void *base1, size_t n, size_t size,
- cmp_r_func_t cmp_func,
- swap_r_func_t swap_func,
- const void *priv)
-{
- unsigned i, j, k;
-
- /* called from 'sort' without swap function, let's pick the default */
- if (swap_func == SWAP_WRAPPER && !((struct wrapper *)priv)->swap_func)
- swap_func = NULL;
-
- if (!swap_func) {
- if (is_aligned(base1, size, 8))
- swap_func = SWAP_WORDS_64;
- else if (is_aligned(base1, size, 4))
- swap_func = SWAP_WORDS_32;
- else
- swap_func = SWAP_BYTES;
- }
-
- /* heapify */
- for (i = n / 2; i >= 1; --i) {
- /* Find the sift-down path all the way to the leaves. */
- for (j = i; k = j * 2, k < n;)
- j = eytzinger1_do_cmp(base1, n, size, cmp_func, priv, k, k + 1) > 0 ? k : k + 1;
-
- /* Special case for the last leaf with no sibling. */
- if (j * 2 == n)
- j *= 2;
-
- /* Backtrack to the correct location. */
- while (j != i && eytzinger1_do_cmp(base1, n, size, cmp_func, priv, i, j) >= 0)
- j /= 2;
-
- /* Shift the element into its correct place. */
- for (k = j; j != i;) {
- j /= 2;
- eytzinger1_do_swap(base1, n, size, swap_func, priv, j, k);
- }
- }
-
- /* sort */
- for (i = n; i > 1; --i) {
- eytzinger1_do_swap(base1, n, size, swap_func, priv, 1, i);
-
- /* Find the sift-down path all the way to the leaves. */
- for (j = 1; k = j * 2, k + 1 < i;)
- j = eytzinger1_do_cmp(base1, n, size, cmp_func, priv, k, k + 1) > 0 ? k : k + 1;
-
- /* Special case for the last leaf with no sibling. */
- if (j * 2 + 1 == i)
- j *= 2;
-
- /* Backtrack to the correct location. */
- while (j >= 1 && eytzinger1_do_cmp(base1, n, size, cmp_func, priv, 1, j) >= 0)
- j /= 2;
-
- /* Shift the element into its correct place. */
- for (k = j; j > 1;) {
- j /= 2;
- eytzinger1_do_swap(base1, n, size, swap_func, priv, j, k);
- }
- }
-}
-
-void eytzinger0_sort_r(void *base, size_t n, size_t size,
- cmp_r_func_t cmp_func,
- swap_r_func_t swap_func,
- const void *priv)
-{
- void *base1 = base - size;
-
- return eytzinger1_sort_r(base1, n, size, cmp_func, swap_func, priv);
-}
-
-void eytzinger0_sort(void *base, size_t n, size_t size,
- cmp_func_t cmp_func,
- swap_func_t swap_func)
-{
- struct wrapper w = {
- .cmp = cmp_func,
- .swap_func = swap_func,
- };
-
- return eytzinger0_sort_r(base, n, size, _CMP_WRAPPER, SWAP_WRAPPER, &w);
-}
-
-#if 0
-#include <linux/slab.h>
-#include <linux/random.h>
-#include <linux/ktime.h>
-
-static u64 cmp_count;
-
-static int mycmp(const void *a, const void *b)
-{
- u32 _a = *(u32 *)a;
- u32 _b = *(u32 *)b;
-
- cmp_count++;
- if (_a < _b)
- return -1;
- else if (_a > _b)
- return 1;
- else
- return 0;
-}
-
-static int test(void)
-{
- size_t N, i;
- ktime_t start, end;
- s64 delta;
- u32 *arr;
-
- for (N = 10000; N <= 100000; N += 10000) {
- arr = kmalloc_array(N, sizeof(u32), GFP_KERNEL);
- cmp_count = 0;
-
- for (i = 0; i < N; i++)
- arr[i] = get_random_u32();
-
- start = ktime_get();
- eytzinger0_sort(arr, N, sizeof(u32), mycmp, NULL);
- end = ktime_get();
-
- delta = ktime_us_delta(end, start);
- printk(KERN_INFO "time: %lld\n", delta);
- printk(KERN_INFO "comparisons: %lld\n", cmp_count);
-
- u32 prev = 0;
-
- eytzinger0_for_each(i, N) {
- if (prev > arr[i])
- goto err;
- prev = arr[i];
- }
-
- kfree(arr);
- }
- return 0;
-
-err:
- kfree(arr);
- return -1;
-}
-#endif