Path: utzoo!utgpu!attcan!uunet!husc6!ogccse!blake!uw-beaver!mit-eddie!bbn!rochester!pt.cs.cmu.edu!cadre!pitt!darth!libove!root
From: root@libove.UUCP (Jay M. Libove)
Newsgroups: comp.lang.c
Subject: Re: question about shift operator
Message-ID: <192@libove.UUCP>
Date: 4 Nov 88 18:40:13 GMT
References: <786@gtx.com>
Distribution: na
Organization: Libove, Pittsburgh, PA, U.S.A.
Lines: 41

From article <786@gtx.com>, by randy@gtx.com (Randy D. Miller):
> I've seen conflicting information about the shift operator in cases
> where operand2 is exactly equal to the number of bits in the object.
> E.g., with a 32 bit int, what must the following do?
> 
>      int n;
>      n <<= 32;

Boy am I confused.

Looking at the above, I read it to be "shift an n-bit integer n bits left"
which would presumably have the following effect:

(let n=8 for simplicity)

i = abcdefgh
shift left one
i = bcdefgh0
shift left one
i = cdefgh00
...
shift left the last time
i = 00000000

Now, why is there any question as to the result?

(One machine test: SCO Xenix 286 v2.2.1 results 0 from

	int x;

	x=0xffff;
	x <<= 16;
	printf("%d\n",x);

)

-- 
Jay Libove		ARPA:	jl42@andrew.cmu.edu or libove@cs.cmu.edu
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