libowfat/mult/umult32.c
leitner fb1f19042f support gcc 5 builtins for multiplication overflow in safemult.h
fix copypasted comment in fmt_asn1dertag
add man pages for add_of, sub_of and assign
2015-09-29 14:42:40 +00:00

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C

#if defined(__GNUC__) && (__GNUC__ >= 5)
#include "uint32.h"
int umult32(uint32 a,uint32 b,uint32* c) { return !__builtin_mul_overflow(a,b,c); }
#else
#include "safemult.h"
int umult32(uint32 a,uint32 b,uint32* c) {
unsigned long long x=(unsigned long long)a*b;
if (x>0xffffffff) return 0;
*c=x&0xffffffff;
return 1;
}
#endif