Files
jehanne/sys/src/lib/mp/port/mptov.c
Giacomo Tesio e70feee4a3 libc: introduce "jehanne_" namespace
With this commit all functions declared in libc.h have been renamed
with the "jehanne_" prefix. This is done for several reason:

- it removes conflicts during symbol resolution when linking
  standard C libraries like newlib or musl
- it allows programs depending on a standard C library to directly
  link to a library depending on our non standard libc (eg libsec).

To ease transiction two files are provided:

- sys/include/lib9.h that can be included instead of <libc.h> to use
  the old names (via a simple set of macros)
- sys/src/lib/c/lib9.c that can be compiled with a program where the
  macro provided by lib9.h are too dumb (see for example rc or grep).

In the kernel port/lib.h has been modified accordingly and some of
the functions it directly provides has been renamed too (eg malloc
in qmalloc.c and print in devcons.c).
2017-04-19 23:48:21 +02:00

64 lines
1000 B
C

#include "os.h"
#include <mp.h>
#include "dat.h"
#define VLDIGITS (sizeof(int64_t)/sizeof(mpdigit))
/*
* this code assumes that a int64_t is an integral number of
* mpdigits int32_t.
*/
mpint*
vtomp(int64_t v, mpint *b)
{
int s;
uint64_t uv;
if(b == nil){
b = mpnew(VLDIGITS*sizeof(mpdigit));
jehanne_setmalloctag(b, jehanne_getcallerpc());
}else
mpbits(b, VLDIGITS*sizeof(mpdigit));
b->sign = (v >> (sizeof(v)*8 - 1)) | 1;
uv = v * b->sign;
for(s = 0; s < VLDIGITS; s++){
b->p[s] = uv;
uv >>= sizeof(mpdigit)*8;
}
b->top = s;
return mpnorm(b);
}
int64_t
mptov(mpint *b)
{
uint64_t v;
int s;
if(b->top == 0)
return 0LL;
if(b->top > VLDIGITS){
if(b->sign > 0)
return (int64_t)MAXVLONG;
else
return (int64_t)MINVLONG;
}
v = 0ULL;
for(s = 0; s < b->top; s++)
v |= b->p[s]<<(s*sizeof(mpdigit)*8);
if(b->sign > 0){
if(v > MAXVLONG)
v = MAXVLONG;
} else {
if(v > MINVLONG)
v = MINVLONG;
else
v = -(int64_t)v;
}
return (int64_t)v;
}