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[/] [openrisc/] [trunk/] [gnu-stable/] [newlib-1.18.0/] [newlib/] [libc/] [machine/] [mips/] [memcpy.c] - Rev 859
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/* FUNCTION <<memcpy>>---copy memory regions, optimized for the mips processors ANSI_SYNOPSIS #include <string.h> void* memcpy(void *<[out]>, const void *<[in]>, size_t <[n]>); TRAD_SYNOPSIS void *memcpy(<[out]>, <[in]>, <[n]> void *<[out]>; void *<[in]>; size_t <[n]>; DESCRIPTION This function copies <[n]> bytes from the memory region pointed to by <[in]> to the memory region pointed to by <[out]>. If the regions overlap, the behavior is undefined. RETURNS <<memcpy>> returns a pointer to the first byte of the <[out]> region. PORTABILITY <<memcpy>> is ANSI C. <<memcpy>> requires no supporting OS subroutines. QUICKREF memcpy ansi pure */ #include <_ansi.h> #include <stddef.h> #include <limits.h> #ifdef __mips64 #define wordtype long long #else #define wordtype long #endif /* Nonzero if either X or Y is not aligned on a "long" boundary. */ #define UNALIGNED(X, Y) \ (((long)X & (sizeof (wordtype) - 1)) | ((long)Y & (sizeof (wordtype) - 1))) /* How many bytes are copied each iteration of the 4X unrolled loop. */ #define BIGBLOCKSIZE (sizeof (wordtype) << 2) /* How many bytes are copied each iteration of the word copy loop. */ #define LITTLEBLOCKSIZE (sizeof (wordtype)) /* Threshhold for punting to the byte copier. */ #define TOO_SMALL(LEN) ((LEN) < BIGBLOCKSIZE) _PTR _DEFUN (memcpy, (dst0, src0, len0), _PTR dst0 _AND _CONST _PTR src0 _AND size_t len0) { #if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) || defined(__mips16) char *dst = (char *) dst0; char *src = (char *) src0; _PTR save = dst0; while (len0--) { *dst++ = *src++; } return save; #else char *dst = dst0; _CONST char *src = src0; wordtype *aligned_dst; _CONST wordtype *aligned_src; int len = len0; size_t iter; /* Handle aligned moves here. */ if (!UNALIGNED (src, dst)) { iter = len / BIGBLOCKSIZE; len = len % BIGBLOCKSIZE; aligned_dst = (wordtype *)dst; aligned_src = (wordtype *)src; /* Copy 4X long or long long words at a time if possible. */ while (iter > 0) { wordtype tmp0 = aligned_src[0]; wordtype tmp1 = aligned_src[1]; wordtype tmp2 = aligned_src[2]; wordtype tmp3 = aligned_src[3]; aligned_dst[0] = tmp0; aligned_dst[1] = tmp1; aligned_dst[2] = tmp2; aligned_dst[3] = tmp3; aligned_src += 4; aligned_dst += 4; iter--; } /* Copy one long or long long word at a time if possible. */ iter = len / LITTLEBLOCKSIZE; len = len % LITTLEBLOCKSIZE; while (iter > 0) { *aligned_dst++ = *aligned_src++; iter--; } /* Pick up any residual with a byte copier. */ dst = (char*)aligned_dst; src = (char*)aligned_src; while (len > 0) { *dst++ = *src++; len--; } return dst0; } /* Handle unaligned moves here, using lwr/lwl and swr/swl where possible */ else { #ifndef NO_UNALIGNED_LOADSTORE int tmp; int *int_src = (int *)src; int *int_dst = (int *)dst; iter = len / 4; len = len % 4; while (iter > 0) { __asm__ ("ulw %0,%1" : "=r" (tmp) : "m" (*int_src)); iter--; int_src++; __asm__ ("usw %1,%0" : "=m" (*int_dst) : "r" (tmp)); int_dst++; } /* Pick up any residual with a byte copier. */ dst = (char*)int_dst; src = (char*)int_src; #endif while (len > 0) { *dst++ = *src++; len--; } return dst0; } #endif /* not PREFER_SIZE_OVER_SPEED */ }
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