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/*
* Type conversion routines, these have been rewritten for portability.
*
* The only requirement is now that the u2_t and u4_t must be big enough.
*/
#include "syshead.h"
#include "const.h"
#include "type.h"
#include "globvar.h"
void xxerr P((char *));
void xxerr(x) char * x; { write(2, x, strlen(x)); }
#ifdef __AS386_16__
static int no_swap = 1;
#endif
static int long_off[4] = {0,1,2,3};
static int int_off[2] = {0,1};
PUBLIC bool_pt typeconv_init(big_endian, long_big_endian)
bool_pt big_endian;
bool_pt long_big_endian;
{
int i;
#ifdef __AS386_16__
no_swap = (!big_endian && !long_big_endian);
#endif
for(i=0; i<4; i++) long_off[i] = i;
for(i=0; i<2; i++) int_off[i] = i;
if( long_big_endian )
{
i = long_off[0]; long_off[0] = long_off[2]; long_off[2] = i;
i = long_off[1]; long_off[1] = long_off[3]; long_off[3] = i;
}
if( big_endian )
{
i = long_off[2]; long_off[2] = long_off[3]; long_off[3] = i;
i = long_off[0]; long_off[0] = long_off[1]; long_off[1] = i;
i = int_off[0]; int_off[0] = int_off[1]; int_off[1] = i;
}
return 1;
}
PUBLIC void u2c2(buf, offset)
char *buf;
u2_pt offset;
{
#ifdef __AS386_16__
if( no_swap )
{
*((unsigned short*)buf) = offset; /* UNALIGNED ACCESS! */
return;
}
#endif
buf[int_off[0]] = offset;
buf[int_off[1]] = (offset>>8);
}
PUBLIC void u4c4(buf, offset)
char *buf;
u4_t offset;
{
int i;
#ifdef __AS386_16__
if( no_swap )
{
*((unsigned long*)buf) = offset; /* UNALIGNED ACCESS! */
return;
}
#endif
for(i=0; i<4; i++)
{
buf[long_off[i]] = offset;
offset >>= 8;
}
}
PUBLIC void u4cn(buf, offset, count)
char *buf;
u4_t offset;
unsigned count;
{
switch(count)
{
case 1:
buf[0] = (char) offset;
return;
case 2:
u2c2(buf, (u2_pt) offset);
return;
case 4:
u4c4(buf, (u4_t) offset);
return;
default:
xxerr("WARNING: typeconv.c(u4cn) illegal count\n");
return;
}
}
PUBLIC void u2cn(buf, offset, count)
char *buf;
u2_pt offset;
unsigned count;
{
switch(count)
{
case 1:
buf[0] = (char) offset;
return;
case 2:
u2c2(buf, (u2_pt) offset);
return;
case 4:
u4c4(buf, (u4_t) offset);
return;
default:
xxerr("WARNING: typeconv.c(u2cn) illegal count\n");
return;
}
}
PUBLIC u2_pt c2u2(buf)
char *buf;
{
u2_pt res;
#ifdef __AS386_16__
if( no_swap ) return *((u2_pt *)buf); /* UNALIGNED ACCESS! */
#endif
res = ((unsigned char *)buf) [int_off[0]]
+ ((((unsigned char *)buf) [int_off[1]]) << 8);
return res;
}
PUBLIC u4_t c4u4(buf)
char *buf;
{
u4_t res;
int i;
#ifdef __AS386_16__
if( no_swap ) return *((u4_t *)buf); /* UNALIGNED ACCESS! */
#endif
res = 0;
for(i=3; i>=0; i--)
{
res = (res<<8) + ((unsigned char *)buf) [long_off[i]];
}
return res;
}
PUBLIC u4_t cnu4(buf, count)
char *buf;
unsigned count;
{
switch (count)
{
case 0:
return 0;
case 1:
return buf[0] & 0xFF;
case 2:
return c2u2(buf);
case 4:
return c4u4(buf);
default:
xxerr("WARNING: typeconv.c(cnu4) illegal count\n");
return 0;
}
}
PUBLIC u2_pt cnu2(buf, count)
char *buf;
unsigned count;
{
switch (count)
{
case 0:
return 0;
case 1:
return buf[0] & 0xFF;
case 2:
return c2u2(buf);
case 4:
return (u2_pt) c4u4(buf);
default:
xxerr("WARNING: typeconv.c(cnu2) illegal count\n");
return 0;
}
}
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