This code fails on 64-bit archs because it relies on the accuracy of a
double to be sufficient to represent LONG_MAX. The patch adresses it by
checking for overflow by reversing the calculation instead of casting to
a double and back to long.
#include "build/php5-cvs/Zend/zend_multiply.h"
#define LONG_MIN (1L << (8*sizeof(long)-1))
#define LONG_MAX ~LONG_MIN
int main()
{
long res = 0;
double d = 0;
int overflow;
/* obviously (LONG_MAX-1) * 1 can be represented by a long */
ZEND_SIGNED_MULTIPLY_LONG(LONG_MAX-1,1,res,d,overflow);
printf("res: %ld/%.4f, %soverflow\n", result, d, overflow?"":"no ");
return 0;
}
--
Ard
