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Update memcpy(3) to current coding style.

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This commit is contained in:
Jonas 'Sortie' Termansen 2014-09-25 15:15:36 +02:00
parent 163ecfcf55
commit fb7db21a1b
1 changed files with 45 additions and 55 deletions
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100
libc/string/memcpy.cpp
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@ -1,6 +1,6 @@
/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2014.
This file is part of the Sortix C Library.
@ -25,105 +25,95 @@
#include <stdint.h>
#include <string.h>
#if 8 < __SIZEOF_LONG__
#error unsigned long is bigger than expected, please add support to this file.
#endif
inline static void* memcpy_slow(void* restrict dstptr,
const void* restrict srcptr, size_t length)
inline static
void* memcpy_slow(void* restrict dst_ptr,
const void* restrict src_ptr,
size_t size)
{
uint8_t* restrict dst = (uint8_t* restrict) dstptr;
const uint8_t* restrict src = (const uint8_t* restrict) srcptr;
for ( size_t i = 0; i < length; i += sizeof(uint8_t) )
unsigned char* restrict dst = (unsigned char* restrict) dst_ptr;
const unsigned char* restrict src = (const unsigned char* restrict) src_ptr;
for ( size_t i = 0; i < size; i++ )
dst[i] = src[i];
return dstptr;
return dst_ptr;
}
extern "C" void* memcpy(void* restrict dstptr, const void* restrict srcptr,
size_t length)
extern "C"
void* memcpy(void* restrict dst_ptr,
const void* restrict src_ptr,
size_t size)
{
const unsigned long unalignmask = sizeof(unsigned long) - 1;
const unsigned long srcunalign = (unsigned long) srcptr & unalignmask;
const unsigned long dstunalign = (unsigned long) dstptr & unalignmask;
if ( srcunalign != dstunalign )
return memcpy_slow(dstptr, srcptr, length);
#if 8 < __SIZEOF_LONG__
#warning "you should add support for your unexpectedly large unsigned long."
return memcpy_slow(dst_ptr, src_ptr, size);
#else
unsigned long unalign_mask = sizeof(unsigned long) - 1;
unsigned long src_unalign = (unsigned long) src_ptr & unalign_mask;
unsigned long dst_unalign = (unsigned long) dst_ptr & unalign_mask;
if ( src_unalign != dst_unalign )
return memcpy_slow(dst_ptr, src_ptr, size);
union
{
unsigned long srcval;
const uint8_t* restrict src8;
const unsigned char* restrict src8;
const uint16_t* restrict src16;
const uint32_t* restrict src32;
const uint64_t* restrict src64;
const unsigned long* restrict srcul;
};
srcval = (unsigned long) srcptr;
srcval = (unsigned long) src_ptr;
union
{
unsigned long dstval;
uint8_t* restrict dst8;
unsigned char* restrict dst8;
uint16_t* restrict dst16;
uint32_t* restrict dst32;
uint64_t* restrict dst64;
unsigned long* restrict dstul;
};
dstval = (unsigned long) dstptr;
dstval = (unsigned long) dst_ptr;
if ( dstunalign )
if ( dst_unalign )
{
if ( 1 <= length && !(dstval & (1-1)) && (dstval & (2-1)) )
if ( 1 <= size && !(dstval & (1-1)) && (dstval & (2-1)) )
*dst8++ = *src8++,
length -= 1;
size -= 1;
if ( 2 <= length && !(dstval & (2-1)) && (dstval & (4-1)) )
if ( 2 <= size && !(dstval & (2-1)) && (dstval & (4-1)) )
*dst16++ = *src16++,
length -= 2;
size -= 2;
#if 8 <= __SIZEOF_LONG__
if ( 4 <= length && !(dstval & (4-1)) && (dstval & (8-1)) )
if ( 4 <= size && !(dstval & (4-1)) && (dstval & (8-1)) )
*dst32++ = *src32++,
length -= 4;
size -= 4;
#endif
}
size_t numcopies = length / sizeof(unsigned long);
#if 0
#if defined(__x86_64__) || defined(__i386__)
unsigned long zeroed_numcopies;
#if defined(__x86_64__)
asm volatile ("rep movsq" : "=c"(zeroed_numcopies), "=S"(srcul), "=D"(dstul)
: "c"(numcopies), "S"(srcul), "D"(dstul)
: "memory");
#elif defined(__i386__)
asm volatile ("rep movsd" : "=c"(zeroed_numcopies), "=S"(srcul), "=D"(dstul)
: "c"(numcopies), "S"(srcul), "D"(dstul)
: "memory");
#endif
#endif
#else
for ( size_t i = 0; i < numcopies; i++ )
size_t num_copies = size / sizeof(unsigned long);
for ( size_t i = 0; i < num_copies; i++ )
*dstul++ = *srcul++;
#endif
length -= numcopies * sizeof(unsigned long);
size -= num_copies * sizeof(unsigned long);
if ( length )
if ( size )
{
#if 8 <= __SIZEOF_LONG__
if ( 4 <= length )
if ( 4 <= size )
*dst32++ = *src32++,
length -= 4;
size -= 4;
#endif
if ( 2 <= length )
if ( 2 <= size )
*dst16++ = *src16++,
length -= 2;
size -= 2;
if ( 1 <= length )
if ( 1 <= size )
*dst8++ = *src8++,
length -= 1;
size -= 1;
}
return dstptr;
return dst_ptr;
#endif
}