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