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Subject: Re: boundschecking

Author: Uri Blass

Date: 01:59:03 11/04/02

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On November 04, 2002 at 04:32:20, Severi Salminen wrote:

>>I can see randomize when I click F1 only as a visual basic command and I work in
>>C.
>>
>>I tried srand(0) before filling the array but it does not help and
>>zobrist[0][0][0] is different in debug mode and in release mode.
>
>Are you sure? I think rand() should return the exact same values if you use the
>same seed (srand()). Are you sure you run srand(0) and fill the table only once
>in both versions? There seems to be a bug somewhere.
>
>Severi

I do not know maybe the problem is that I use rand64 for 64 bits numbers

Here is the beginning of my code

int main(void)
{
	char s[256];
	int i=0;
	char sizehash[9]="aaaaaaaaa";
	int hash_in_mbytes=0;
	FILE *hashfile=fopen("movei137info.txt", "r+t");
	int fil,j;
	srand(0);
	for (fil=0;fil<6;fil++)
		for (i=0;i<2;i++)
			for (j=0;j<64;j++)
				zobrist[fil][i][j]=rand64();
			printf(" %d ",(zobrist[0][0][0]&1048575));


In debug mode I get 229414 and in release mode I get 172695.


If I use rand instead of rand64 I get 38 in both cases
Here is my function rand64 that is in another file in my project.

__int64 rand64()
{
	return rand()^((__int64)rand()<<15)^((__int64)rand()<<30)^
		((__int64)rand()<<45)^((__int64)rand()<<60);
}


Uri



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