🚀 go-pugleaf

(We're running SunOS 4.1.1 on a Sun 4/75.)

Description:
	gcc 2.7.2 sometimes produces incorrect results if its "-funroll-loops"
	option is used on a SPARC box.

Repeat-By:
	The code below should set each of the four elements of the "uc" array
	to 1.  It does the right thing without -funroll-loops; it does the
	wrong thing with -funroll-loops.

	Script started on Thu Dec 28 12:31:50 1995
	elsie$ cat try.c
	int
	main()
	{
		unsigned char	uc[4];
		int		col;
		int		bitshift;
		unsigned char	item;

		bitshift = -1;
		for (col = 0; col < sizeof uc; ++col) {
			if (bitshift == -1) {
				item = 255;
				bitshift = 7;
			}
			uc[col] = (item >> bitshift) & 1;
			--bitshift;
		}
		if (uc[0] + uc[1] + uc[2] + uc[3] != 4)
			printf("OOPS!\n");
		return 0;
	}
	elsie$ /usr/local/bin/gcc --version
	2.7.2
	elsie$ /usr/local/bin/gcc -O try.c
	elsie$ a.out
	elsie$ /usr/local/bin/gcc -O -funroll-loops try.c
	elsie$ a.out
>>>>	OOPS!
	elsie$ exit

	script done on Thu Dec 28 12:32:25 1995
-- 
            "His twin Midas was in medicine too--sold mineral waters."
        --intro from "Robert Young Sings the Rodgers & Hammerstein Songbook"
		Arthur David Olson	arthur_david_olson@nih.gov