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From: shahriar@island.COM (Shahriar Vaghar)
Newsgroups: comp.sys.mac.programmer
Subject: MPW C ver. 3.2b1 bug
Keywords: type conversion
Message-ID: <3923@island.COM>
Date: 15 Apr 91 17:06:47 GMT
Distribution: usa
Organization: Island Graphics, Marin County, California
Lines: 59


/*
cc -mc68881 -elems881 -mc68020 unsigned.c
Link -w -c 'MPS ' -t 'MPST' unsigned.c.o 6
	-sn STDIO=Main 6
	-sn INTENV=Main 6
	-sn %A5Init=Main 6
	"{Libraries}"Stubs.o 6
	"{CLibraries}"CLib881.o 6
	"{CLibraries}"CRuntime.o 6
	"{CLibraries}"StdCLib.o 6
	"{CLibraries}"CInterface.o 6
	"{CLibraries}"Math881.o 6
	"{CLibraries}"CSANElib881.o 6
	"{Libraries}"Interface.o 6
	-o unsigned

	The following program produces correct result when compiled with
	MPW C 3.1. But produces wrong output when compiled with MPW C 3.2b1.
	Mac IIfx running 6.05.
*/

#include <stdio.h>

unsigned char red[10];
unsigned char green[10];

main()
{
    int v;

    for (v = 0; v < 10; v++) {
	double val;
	val = ((double)v / 255.);

	red[v] = (int) (255. * val);	/* ???? */
	green[v] = 255. * val;		/* ???? */

	fprintf(stderr,"red[%d]  = %d", v, red[v]);
	fprintf(stderr, "         ");
	fprintf(stderr,"green[%d]  = %d", v, green[v]);
	fprintf(stderr, "\n");
    }
}



/* Output:
red[0]  = 0         green[0]  = 0
red[1]  = 0         green[1]  = 0
red[2]  = 0         green[2]  = 1
red[3]  = 0         green[3]  = 2
red[4]  = 0         green[4]  = 3
red[5]  = 0         green[5]  = 4
red[6]  = 0         green[6]  = 5
red[7]  = 0         green[7]  = 6
red[8]  = 0         green[8]  = 7
red[9]  = 0         green[9]  = 8
*/