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From: john@auspyr.UUCP (John Weald)
Newsgroups: comp.os.vms
Subject: re: where is C$MEMFUNC
Message-ID: <9051@auspyr.UUCP>
Date: Fri, 11-Sep-87 12:44:46 EDT
Article-I.D.: auspyr.9051
Posted: Fri Sep 11 12:44:46 1987
Date-Received: Sun, 13-Sep-87 02:22:09 EDT
Reply-To: john@auspyr.UUCP (John Weald)
Organization: Austec, Inc. San Jose
Lines: 67



On the subject of the memxxx functions here is a bug. We are running
on one of those strange combinations mentioned in earlier articles.
We have VMS 4.5 with a C 2.3 compiler and RTL on a uVAX.

It would appear that memset() does not save/restore the registers. Here
is a sample program:

++++++++++++++++++Cut here+++++++++++++++++++++++++++++++++++++++
main(argc, argv)
int argc;
char *argv[];
{              
	char b[100];
	int r1;	/* These guys will be in registers		*/
	int r2;
	int r3; /* This guy is in R6				*/
	int r4;
	int r5;
	int r6;



	/* assign them something that the compiler    */
	/* will not be clever with		      */
	r1 = atoi(argv[1]);
	r2 = atoi(argv[2]);
	r3 = atoi(argv[3]);
	r4 = atoi(argv[4]);
	r5 = atoi(argv[5]);
	r6 = atoi(argv[6]);


	f(r1, r2, r3, r4, r5, r6);

	memset(b, 0, sizeof(b));

	f(r1, r2, r3, r4, r5, r6);       
}

f(a1, a2, a3, a4, a5, a6)
int a1, a2, a3, a4, a5, a6;
{
	printf("%d %d %d %d %d %d\n",
		 a1, a2, a3, a4, a5, a6);
}


Compile it in the usual manner. Install the command with the usual:

	proggie = "$ dev:[path]proggie.exe"

and run it as:
	proggie 1 2 3 4 5 6

the output is:

	1 2 3 4 5 6 
	1 2 0 4 5 6

Using the debugger it is R6 that gets corrupted.

Cheers!
	John Weald 	Austec Inc.	San Jose	
-- 
UUCP: {styx,imagen,dlb,gould,sci,altnet}!auspyr!john