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From: johnl@esegue.segue.boston.ma.us (John R. Levine)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Turbo C far pointers
Message-ID: <1989Nov16.155005.6689@esegue.segue.boston.ma.us>
Date: 16 Nov 89 15:50:05 GMT
References: <wZHEDrW00VoH479lIM@andrew.cmu.edu> <4037@cs.yale.edu> <579@gmuvax2.gmu.edu>
Reply-To: johnl@esegue.segue.boston.ma.us (John R. Levine)
Organization: Segue Software, Cambridge MA
Lines: 17

In article <579@gmuvax2.gmu.edu> 2179ak@gmuvax2.UUCP (JDPorter) writes:
>>That's ridiculous. *(A+1), A[1], and 1[A] all produce exactly the same code.

>*(A+1) does NOT produce the same code as A[1].  (not for MSC, anyway.)

Congratulations, you've found an optimization bug in MSC.  In Turbo, assuming
that A is an int * passed as an argument, they all generate these two
instructions (picked verbatim from the generated .ASM):

	mov	bx,word ptr [bp+4]
	mov	ax,word ptr [bx+2]

Can we stop arguing about this now?
-- 
John R. Levine, Segue Software, POB 349, Cambridge MA 02238, +1 617 864 9650
johnl@esegue.segue.boston.ma.us, {ima|lotus|spdcc}!esegue!johnl
"Now, we are all jelly doughnuts."