Mirror of :pserver:cvs@cvs.fefe.de:/cvs libowfat https://www.fefe.de/libowfat/
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

31 lines
527 B

#if defined(__GNUC__) && (__GNUC__ >= 5)
#include "uint16.h"
int umult16(uint16 a,uint16 b,uint16* c) { return !__builtin_mul_overflow(a,b,c); }
#else
#include "safemult.h"
int umult16(uint16 a,uint16 b,uint16* c) {
unsigned long x=(unsigned long)a*b;
if (x>0xffff) return 0;
*c=x&0xffff;
return 1;
}
#endif
#ifdef UNITTEST
#include <assert.h>
int main() {
uint16 a;
assert(umult16(7,10000,&a)==0);
assert(umult16(5,10,&a)==1 && a==50);
assert(umult16(6,10000,&a)==1 && a==60000);
return 0;
}
#endif