From 8cace3f05003c6cb4d38c36890055f03151c2ad4 Mon Sep 17 00:00:00 2001
From: Richard Qin <richard.qin.x@gmail.com>
Date: Fri, 16 Oct 2026 02:39:56 +0800
Subject: Remove old code

Signed-off-by: Richard Qin <richard.qin.x@gmail.com>
---
 lib/string/memmem.c | 152 ----------------------------------------------------
 1 file changed, 152 deletions(-)
 delete mode 100644 lib/string/memmem.c

(limited to 'lib/string/memmem.c')

diff --git a/lib/string/memmem.c b/lib/string/memmem.c
deleted file mode 100644
index cfd23bb..0000000
--- a/lib/string/memmem.c
+++ /dev/null
@@ -1,152 +0,0 @@
-/* SPDX-License-Identifier: MIT */
-/* Derived from musl libc (Copyright © 2005-2020 Rich Felker, et al.) */
-
-#define _GNU_SOURCE
-#include <string.h>
-#include <stdint.h>
-
-static char *twobyte_memmem(const unsigned char *h, size_t k, const unsigned char *n)
-{
-	uint16_t nw = n[0]<<8 | n[1], hw = h[0]<<8 | h[1];
-	for (h+=2, k-=2; k; k--, hw = hw<<8 | *h++)
-		if (hw == nw) return (char *)h-2;
-	return hw == nw ? (char *)h-2 : 0;
-}
-
-static char *threebyte_memmem(const unsigned char *h, size_t k, const unsigned char *n)
-{
-	uint32_t nw = (uint32_t)n[0]<<24 | n[1]<<16 | n[2]<<8;
-	uint32_t hw = (uint32_t)h[0]<<24 | h[1]<<16 | h[2]<<8;
-	for (h+=3, k-=3; k; k--, hw = (hw|*h++)<<8)
-		if (hw == nw) return (char *)h-3;
-	return hw == nw ? (char *)h-3 : 0;
-}
-
-static char *fourbyte_memmem(const unsigned char *h, size_t k, const unsigned char *n)
-{
-	uint32_t nw = (uint32_t)n[0]<<24 | n[1]<<16 | n[2]<<8 | n[3];
-	uint32_t hw = (uint32_t)h[0]<<24 | h[1]<<16 | h[2]<<8 | h[3];
-	for (h+=4, k-=4; k; k--, hw = hw<<8 | *h++)
-		if (hw == nw) return (char *)h-4;
-	return hw == nw ? (char *)h-4 : 0;
-}
-
-#define MAX(a,b) ((a)>(b)?(a):(b))
-#define MIN(a,b) ((a)<(b)?(a):(b))
-
-#define BITOP(a,b,op) \
- ((a)[(size_t)(b)/(8*sizeof *(a))] op (size_t)1<<((size_t)(b)%(8*sizeof *(a))))
-
-static char *twoway_memmem(const unsigned char *h, const unsigned char *z, const unsigned char *n, size_t l)
-{
-	size_t i, ip, jp, k, p, ms, p0, mem, mem0;
-	size_t byteset[32 / sizeof(size_t)] = { 0 };
-	size_t shift[256];
-
-	/* Computing length of needle and fill shift table */
-	for (i=0; i<l; i++)
-		BITOP(byteset, n[i], |=), shift[n[i]] = i+1;
-
-	/* Compute maximal suffix */
-	ip = -1; jp = 0; k = p = 1;
-	while (jp+k<l) {
-		if (n[ip+k] == n[jp+k]) {
-			if (k == p) {
-				jp += p;
-				k = 1;
-			} else k++;
-		} else if (n[ip+k] > n[jp+k]) {
-			jp += k;
-			k = 1;
-			p = jp - ip;
-		} else {
-			ip = jp++;
-			k = p = 1;
-		}
-	}
-	ms = ip;
-	p0 = p;
-
-	/* And with the opposite comparison */
-	ip = -1; jp = 0; k = p = 1;
-	while (jp+k<l) {
-		if (n[ip+k] == n[jp+k]) {
-			if (k == p) {
-				jp += p;
-				k = 1;
-			} else k++;
-		} else if (n[ip+k] < n[jp+k]) {
-			jp += k;
-			k = 1;
-			p = jp - ip;
-		} else {
-			ip = jp++;
-			k = p = 1;
-		}
-	}
-	if (ip+1 > ms+1) ms = ip;
-	else p = p0;
-
-	/* Periodic needle? */
-	if (memcmp(n, n+p, ms+1)) {
-		mem0 = 0;
-		p = MAX(ms, l-ms-1) + 1;
-	} else mem0 = l-p;
-	mem = 0;
-
-	/* Search loop */
-	for (;;) {
-		/* If remainder of haystack is shorter than needle, done */
-		if (z-h < l) return 0;
-
-		/* Check last byte first; advance by shift on mismatch */
-		if (BITOP(byteset, h[l-1], &)) {
-			k = l-shift[h[l-1]];
-			if (k) {
-				if (k < mem) k = mem;
-				h += k;
-				mem = 0;
-				continue;
-			}
-		} else {
-			h += l;
-			mem = 0;
-			continue;
-		}
-
-		/* Compare right half */
-		for (k=MAX(ms+1,mem); k<l && n[k] == h[k]; k++);
-		if (k < l) {
-			h += k-ms;
-			mem = 0;
-			continue;
-		}
-		/* Compare left half */
-		for (k=ms+1; k>mem && n[k-1] == h[k-1]; k--);
-		if (k <= mem) return (char *)h;
-		h += p;
-		mem = mem0;
-	}
-}
-
-void *memmem(const void *h0, size_t k, const void *n0, size_t l)
-{
-	const unsigned char *h = h0, *n = n0;
-
-	/* Return immediately on empty needle */
-	if (!l) return (void *)h;
-
-	/* Return immediately when needle is longer than haystack */
-	if (k<l) return 0;
-
-	/* Use faster algorithms for short needles */
-	h = memchr(h0, *n, k);
-	if (!h || l==1) return (void *)h;
-	k -= h - (const unsigned char *)h0;
-	if (k<l) return 0;
-	if (l==2) return twobyte_memmem(h, k, n);
-	if (l==3) return threebyte_memmem(h, k, n);
-	if (l==4) return fourbyte_memmem(h, k, n);
-
-	return twoway_memmem(h, h+k, n, l);
-}
-- 
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