cs444@watrose.UUCP (Course Account) (04/20/86)
While writing test programs for some student compilers, I found a very short Pascal that makes the Berkeley Pascal get stuck in its tracks. Here it is: program main (output); var i, k : integer; begin i := 1; k := i+(i+(i+(i+(i+(i+(i+(i+(i+(i+(i+(i+(i+(i+(i+(i+(i+(i+i ))))))))))))))))); writeln (i, k); end. This program takes over 400 seconds to compile on a VAX-11/780. The time it takes doubles with each nested addition appended to the expression. Thus pc's running time is exponential for expressions of this sort. Conclusion: If your compiles have been taking a long time, see if you can reduce the nesting of parentheses.
koch@unido.UUCP (05/02/86)
on our vax 11/750 it is the same phenomene. but the program is executed very fast. miko, unido
cs444@watrose.UUCP (Course Account) (05/07/86)
The times given were for Berkeley 4.2 UNIX. Apparently the problem has been corrected in 4.3.