35,110 → 35,13 |
#ifndef KERN_amd64_MEMSTR_H_ |
#define KERN_amd64_MEMSTR_H_ |
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/** Copy memory |
* |
* Copy a given number of bytes (3rd argument) |
* from the memory location defined by 2nd argument |
* to the memory location defined by 1st argument. |
* The memory areas cannot overlap. |
* |
* @param dst Destination |
* @param src Source |
* @param cnt Number of bytes |
* @return Destination |
*/ |
static inline void * memcpy(void * dst, const void * src, size_t cnt) |
{ |
unative_t d0, d1, d2; |
#define memcpy(dst, src, cnt) __builtin_memcpy((dst), (src), (cnt)) |
|
asm volatile( |
"rep movsq\n\t" |
"movq %4, %%rcx\n\t" |
"andq $7, %%rcx\n\t" |
"jz 1f\n\t" |
"rep movsb\n\t" |
"1:\n" |
: "=&c" (d0), "=&D" (d1), "=&S" (d2) |
: "0" ((unative_t)(cnt / 8)), "g" ((unative_t)cnt), "1" ((unative_t) dst), "2" ((unative_t) src) |
: "memory"); |
extern void memsetw(void *dst, size_t cnt, uint16_t x); |
extern void memsetb(void *dst, size_t cnt, uint8_t x); |
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return dst; |
} |
extern int memcmp(const void *a, const void *b, size_t cnt); |
|
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/** Compare memory regions for equality |
* |
* Compare a given number of bytes (3rd argument) |
* at memory locations defined by 1st and 2nd argument |
* for equality. If bytes are equal function returns 0. |
* |
* @param src Region 1 |
* @param dst Region 2 |
* @param cnt Number of bytes |
* @return Zero if bytes are equal, non-zero otherwise |
*/ |
static inline int memcmp(const void * src, const void * dst, size_t cnt) |
{ |
unative_t d0, d1, d2; |
unative_t ret; |
|
asm ( |
"repe cmpsb\n\t" |
"je 1f\n\t" |
"movq %3, %0\n\t" |
"addq $1, %0\n\t" |
"1:\n" |
: "=a" (ret), "=&S" (d0), "=&D" (d1), "=&c" (d2) |
: "0" (0), "1" (src), "2" (dst), "3" ((unative_t)cnt) |
); |
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return ret; |
} |
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/** Fill memory with words |
* Fill a given number of words (2nd argument) |
* at memory defined by 1st argument with the |
* word value defined by 3rd argument. |
* |
* @param dst Destination |
* @param cnt Number of words |
* @param x Value to fill |
*/ |
static inline void memsetw(uintptr_t dst, size_t cnt, uint16_t x) |
{ |
unative_t d0, d1; |
|
asm volatile ( |
"rep stosw\n\t" |
: "=&D" (d0), "=&c" (d1), "=&a" (x) |
: "0" (dst), "1" ((unative_t)cnt), "2" (x) |
: "memory" |
); |
|
} |
|
/** Fill memory with bytes |
* Fill a given number of bytes (2nd argument) |
* at memory defined by 1st argument with the |
* word value defined by 3rd argument. |
* |
* @param dst Destination |
* @param cnt Number of bytes |
* @param x Value to fill |
*/ |
static inline void memsetb(uintptr_t dst, size_t cnt, uint8_t x) |
{ |
unative_t d0, d1; |
|
asm volatile ( |
"rep stosb\n\t" |
: "=&D" (d0), "=&c" (d1), "=&a" (x) |
: "0" (dst), "1" ((unative_t)cnt), "2" (x) |
: "memory" |
); |
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} |
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#endif |
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/** @} |