4
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
12
extern void arm64_bzero ( void *dest, size_t len );
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extern void arm64_memset ( void *dest, size_t len, int character );
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extern void arm64_memcpy ( void *dest, const void *src, size_t len );
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extern void arm64_memmove_forwards ( void *dest, const void *src, size_t len );
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extern void arm64_memmove_backwards ( void *dest, const void *src, size_t len );
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extern void arm64_memmove ( void *dest, const void *src, size_t len );
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* @v dest Destination region
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* @v character Fill character
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* @ret dest Destination region
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static inline __attribute__ (( always_inline )) void *
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memset ( void *dest, int character, size_t len ) {
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/* Allow gcc to generate inline "stX xzr" instructions for
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* small, constant lengths.
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if ( __builtin_constant_p ( character ) && ( character == 0 ) &&
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__builtin_constant_p ( len ) && ( len <= 64 ) ) {
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__builtin_memset ( dest, 0, len );
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/* For zeroing larger or non-constant lengths, use the
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* optimised variable-length zeroing code.
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if ( __builtin_constant_p ( character ) && ( character == 0 ) ) {
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arm64_bzero ( dest, len );
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/* Not necessarily zeroing: use basic variable-length code */
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arm64_memset ( dest, len, character );
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* @v dest Destination region
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* @v src Source region
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* @ret dest Destination region
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static inline __attribute__ (( always_inline )) void *
61
memcpy ( void *dest, const void *src, size_t len ) {
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/* Allow gcc to generate inline "ldX"/"stX" instructions for
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* small, constant lengths.
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if ( __builtin_constant_p ( len ) && ( len <= 64 ) ) {
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__builtin_memcpy ( dest, src, len );
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/* Otherwise, use variable-length code */
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arm64_memcpy ( dest, src, len );
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* Copy (possibly overlapping) memory region
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* @v dest Destination region
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* @v src Source region
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* @ret dest Destination region
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static inline __attribute__ (( always_inline )) void *
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memmove ( void *dest, const void *src, size_t len ) {
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ssize_t offset = ( dest - src );
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/* If required direction of copy is known at build time, then
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* use the appropriate forwards/backwards copy directly.
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if ( __builtin_constant_p ( offset ) ) {
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arm64_memmove_forwards ( dest, src, len );
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arm64_memmove_backwards ( dest, src, len );
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/* Otherwise, use ambidirectional copy */
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arm64_memmove ( dest, src, len );
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#endif /* BITS_STRING_H */