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From: larryh@techbook.com (Larry Hutchinson)
Newsgroups: comp.sys.mac.programmer
Subject: Another MPW C 3.2final bug.
Message-ID: <1991Jun21.163520.22236@techbook.com>
Date: 21 Jun 91 16:35:20 GMT
Reply-To: larryh@techbook.com (Larry Hutchinson)
Organization: TECHbooks - Beaverton, Oregon - Public Access Unix
Lines: 84



Following is the text of yet another bug report for MPW C 3.2 final.
I have decided that 3.2f is too buggy to use and am reverting to
the less buggy 3.2b6.  Gack!


***********************************


The following code:

#define CLOSE_DELTA 5
int AbsInt(int);

static int
IsClose(Point p1,Point p2)
{
	return !( (AbsInt(p1.h-p2.h) > CLOSE_DELTA) |
			(AbsInt(p1.v-p2.v) > CLOSE_DELTA) );
}

Produces the following incorrect code.


          LINK       A6,#$FFFC
          MOVE.L     D3,-(A7)
          MOVE.W     $000A(A6),D0
          EXT.L      D0
          MOVE.W     $000E(A6),D1
          EXT.L      D1
          SUB.L      D1,D0
          MOVE.L     D0,-(A7)
          JSR        AbsInt
          MOVEQ      #$05,D1
          CMP.L      D0,D1
          SLT        D0
          NEG.B      D0
          MOVE.L     D0,-$0004(A6)
          MOVE.W     $0008(A6),D0
          EXT.L      D0
          MOVE.W     $000C(A6),D1
          EXT.L      D1
          SUB.L      D1,D0
          MOVE.L     D0,-(A7)
          JSR        AbsInt
          MOVEQ      #$05,D1
          CMP.L      D0,D1
          MOVE.L     -$0004(A6),D0		<----- ERROR
          SLT        D1
          NEG.B      D1
          OR.B       D0,D1
          SEQ        D3
          NEG.B      D3
          EXTB.L     D3
          MOVE.L     D3,D0
          MOVE.L     -$0008(A6),D3
          UNLK       A6
          RTS        
          OR.W       A1,D4
          DC.W       $7343
          BGE.S      *+$0071
          DC.W       $7365
          MOVE.W     D0,D1
          DC.W       $0000 

Note that the move.l at the indicated line destroys the condition
code value from the cmp.l.

Flags:
	 -r -elems881 -mc68020 -mbg full
 
	 -opt off had no effect


***********************************

Larry Hutchinson
WaveMetrics@AppleLink.Apple.COM
or...
-- 
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