Mirror of :pserver:cvs@cvs.fefe.de:/cvs libowfat https://www.fefe.de/libowfat/
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/* this header file comes from libowfat, http://www.fefe.de/libowfat/ */
#ifndef SAFEMULT_H
#define SAFEMULT_H
#include "uint16.h"
#include "uint32.h"
#include "uint64.h"
#ifdef __cplusplus
extern "C" {
#endif
#if defined(__GNUC__) && (__GNUC__ >= 5)
/* for historical reasons, the mult interface uses 0 for failure and 1
* for success, while the builtins (and my own addition and
* subtraction routines in rangecheck.h) do it the other way around. */
static inline int umult16(uint16 a,uint16 b,uint16* c) { return !__builtin_mul_overflow(a,b,c); }
static inline int imult16( int16 a, int16 b, int16* c) { return !__builtin_mul_overflow(a,b,c); }
static inline int umult32(uint32 a,uint32 b,uint32* c) { return !__builtin_mul_overflow(a,b,c); }
static inline int imult32( int32 a, int32 b, int32* c) { return !__builtin_mul_overflow(a,b,c); }
static inline int umult64(uint64 a,uint64 b,uint64* c) { return !__builtin_mul_overflow(a,b,c); }
static inline int imult64( int64 a, int64 b, int64* c) { return !__builtin_mul_overflow(a,b,c); }
#else
/* return 0 for overflow, 1 for ok */
int umult16(uint16 a,uint16 b,uint16* c);
int imult16( int16 a, int16 b, int16* c);
int umult32(uint32 a,uint32 b,uint32* c);
int imult32( int32 a, int32 b, int32* c);
int umult64(uint64 a,uint64 b,uint64* c);
int imult64( int64 a, int64 b, int64* c);
#endif
#ifdef __cplusplus
}
#endif
#endif