253 lines
6.5 KiB
C
253 lines
6.5 KiB
C
/*
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* Taken from Linux /usr/include/asm/string.h
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* All except memcpy, memmove, memset and memcmp removed.
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*/
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#ifndef _I386_STRING_H_
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#define _I386_STRING_H_
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#include <types.h>
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/*
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* This string-include defines all string functions as inline
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* functions. Use gcc. It also assumes ds=es=data space, this should be
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* normal. Most of the string-functions are rather heavily hand-optimized,
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* see especially strtok,strstr,str[c]spn. They should work, but are not
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* very easy to understand. Everything is done entirely within the register
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* set, making the functions fast and clean. String instructions have been
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* used through-out, making for "slightly" unclear code :-)
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*
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* NO Copyright (C) 1991, 1992 Linus Torvalds,
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* consider these trivial functions to be PD.
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*/
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extern void *__memcpy(void * to, const void * from, size_t n);
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extern void *__constant_memcpy(void * to, const void * from, size_t n);
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extern void *memmove(void * dest,const void * src, size_t n);
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extern void *__memset_generic(void * s, char c,size_t count);
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extern void *__constant_c_memset(void * s, unsigned long c, size_t count);
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extern void *__constant_c_and_count_memset(void * s, unsigned long pattern, size_t count);
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extern inline void * __memcpy(void * to, const void * from, size_t n)
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{
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int d0, d1, d2;
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__asm__ __volatile__(
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"cld\n\t"
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"rep ; movsl\n\t"
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"testb $2,%b4\n\t"
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"je 1f\n\t"
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"movsw\n"
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"1:\ttestb $1,%b4\n\t"
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"je 2f\n\t"
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"movsb\n"
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"2:"
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: "=&c" (d0), "=&D" (d1), "=&S" (d2)
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:"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from)
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: "memory");
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return (to);
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}
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/*
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* This looks horribly ugly, but the compiler can optimize it totally,
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* as the count is constant.
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*/
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extern inline void * __constant_memcpy(void * to, const void * from, size_t n)
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{
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switch (n) {
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case 0:
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return to;
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case 1:
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*(unsigned char *)to = *(const unsigned char *)from;
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return to;
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case 2:
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*(unsigned short *)to = *(const unsigned short *)from;
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return to;
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case 3:
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*(unsigned short *)to = *(const unsigned short *)from;
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*(2+(unsigned char *)to) = *(2+(const unsigned char *)from);
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return to;
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case 4:
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*(unsigned long *)to = *(const unsigned long *)from;
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return to;
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case 6: /* for Ethernet addresses */
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*(unsigned long *)to = *(const unsigned long *)from;
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*(2+(unsigned short *)to) = *(2+(const unsigned short *)from);
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return to;
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case 8:
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*(unsigned long *)to = *(const unsigned long *)from;
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*(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
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return to;
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case 12:
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*(unsigned long *)to = *(const unsigned long *)from;
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*(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
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*(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
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return to;
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case 16:
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*(unsigned long *)to = *(const unsigned long *)from;
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*(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
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*(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
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*(3+(unsigned long *)to) = *(3+(const unsigned long *)from);
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return to;
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case 20:
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*(unsigned long *)to = *(const unsigned long *)from;
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*(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
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*(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
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*(3+(unsigned long *)to) = *(3+(const unsigned long *)from);
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*(4+(unsigned long *)to) = *(4+(const unsigned long *)from);
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return to;
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}
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#define COMMON(x) \
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__asm__ __volatile__( \
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"cld\n\t" \
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"rep ; movsl" \
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x \
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: "=&c" (d0), "=&D" (d1), "=&S" (d2) \
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: "0" (n/4),"1" ((long) to),"2" ((long) from) \
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: "memory");
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{
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int d0, d1, d2;
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switch (n % 4) {
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case 0: COMMON(""); return to;
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case 1: COMMON("\n\tmovsb"); return to;
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case 2: COMMON("\n\tmovsw"); return to;
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default: COMMON("\n\tmovsw\n\tmovsb"); return to;
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}
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}
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#undef COMMON
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}
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#define __HAVE_ARCH_MEMCPY
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#define memcpy(t, f, n) \
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(__builtin_constant_p(n) ? \
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__constant_memcpy((t),(f),(n)) : \
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__memcpy((t),(f),(n)))
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#define __HAVE_ARCH_MEMMOVE
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extern inline void * memmove(void * dest,const void * src, size_t n)
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{
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int d0, d1, d2;
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if (dest<src)
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__asm__ __volatile__(
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"cld\n\t"
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"rep\n\t"
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"movsb"
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: "=&c" (d0), "=&S" (d1), "=&D" (d2)
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:"0" (n),"1" (src),"2" (dest)
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: "memory");
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else
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__asm__ __volatile__(
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"std\n\t"
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"rep\n\t"
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"movsb\n\t"
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"cld"
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: "=&c" (d0), "=&S" (d1), "=&D" (d2)
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:"0" (n),
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"1" (n-1+(const char *)src),
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"2" (n-1+(char *)dest)
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:"memory");
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return dest;
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}
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#define memcmp __builtin_memcmp
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extern inline void * __memset_generic(void * s, char c,size_t count)
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{
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int d0, d1;
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__asm__ __volatile__(
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"cld\n\t"
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"rep\n\t"
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"stosb"
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: "=&c" (d0), "=&D" (d1)
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:"a" (c),"1" (s),"0" (count)
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:"memory");
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return s;
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}
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/* we might want to write optimized versions of these later */
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#define __constant_count_memset(s,c,count) __memset_generic((s),(c),(count))
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/*
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* memset(x,0,y) is a reasonably common thing to do, so we want to fill
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* things 32 bits at a time even when we don't know the size of the
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* area at compile-time..
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*/
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extern inline void * __constant_c_memset(void * s, unsigned long c, size_t count)
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{
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int d0, d1;
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__asm__ __volatile__(
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"cld\n\t"
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"rep ; stosl\n\t"
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"testb $2,%b3\n\t"
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"je 1f\n\t"
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"stosw\n"
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"1:\ttestb $1,%b3\n\t"
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"je 2f\n\t"
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"stosb\n"
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"2:"
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: "=&c" (d0), "=&D" (d1)
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:"a" (c), "q" (count), "0" (count/4), "1" ((long) s)
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:"memory");
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return (s);
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}
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/*
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* This looks horribly ugly, but the compiler can optimize it totally,
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* as we by now know that both pattern and count is constant..
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*/
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extern inline void * __constant_c_and_count_memset(void * s, unsigned long pattern, size_t count)
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{
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switch (count) {
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case 0:
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return s;
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case 1:
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*(unsigned char *)s = pattern;
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return s;
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case 2:
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*(unsigned short *)s = pattern;
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return s;
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case 3:
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*(unsigned short *)s = pattern;
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*(2+(unsigned char *)s) = pattern;
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return s;
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case 4:
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*(unsigned long *)s = pattern;
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return s;
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}
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#define COMMON(x) \
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__asm__ __volatile__("cld\n\t" \
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"rep ; stosl" \
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x \
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: "=&c" (d0), "=&D" (d1) \
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: "a" (pattern),"0" (count/4),"1" ((long) s) \
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: "memory")
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{
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int d0, d1;
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switch (count % 4) {
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case 0: COMMON(""); return s;
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case 1: COMMON("\n\tstosb"); return s;
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case 2: COMMON("\n\tstosw"); return s;
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default: COMMON("\n\tstosw\n\tstosb"); return s;
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}
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}
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#undef COMMON
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}
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#define __constant_c_x_memset(s, c, count) \
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(__builtin_constant_p(count) ? \
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__constant_c_and_count_memset((s),(c),(count)) : \
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__constant_c_memset((s),(c),(count)))
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#define __memset(s, c, count) \
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(__builtin_constant_p(count) ? \
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__constant_count_memset((s),(c),(count)) : \
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__memset_generic((s),(c),(count)))
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#define __HAVE_ARCH_MEMSET
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#define memset(s, c, count) \
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(__builtin_constant_p(c) ? \
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__constant_c_x_memset((s),(c),(count)) : \
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__memset((s),(c),(count)))
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#endif
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