34 lines
758 B
C
34 lines
758 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/string.h>
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#include <linux/export.h>
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char *strstr(const char *cs, const char *ct)
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{
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int d0, d1;
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register char *__res;
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__asm__ __volatile__(
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"movl %6,%%edi\n\t"
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"repne\n\t"
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"scasb\n\t"
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"notl %%ecx\n\t"
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"decl %%ecx\n\t" /* NOTE! This also sets Z if searchstring='' */
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"movl %%ecx,%%edx\n"
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"1:\tmovl %6,%%edi\n\t"
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"movl %%esi,%%eax\n\t"
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"movl %%edx,%%ecx\n\t"
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"repe\n\t"
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"cmpsb\n\t"
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"je 2f\n\t" /* also works for empty string, see above */
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"xchgl %%eax,%%esi\n\t"
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"incl %%esi\n\t"
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"cmpb $0,-1(%%eax)\n\t"
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"jne 1b\n\t"
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"xorl %%eax,%%eax\n\t"
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"2:"
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: "=a" (__res), "=&c" (d0), "=&S" (d1)
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: "0" (0), "1" (0xffffffff), "2" (cs), "g" (ct)
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: "dx", "di");
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return __res;
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}
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EXPORT_SYMBOL(strstr);
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