xref: /original-bsd/usr.bin/pascal/px/READ_ME (revision c3e32dec)
1# @(#)READ_ME	8.1 (Berkeley) 06/06/93
2
3   This directory contains the source code for the Version 7 VAX
4interpreter for Pascal. Following standard convensions, the makefile
5contains four commands:
6
7	px - compile px
8
9	install - compile and install px in /usr/ucb
10
11	clean - clean out directory
12
13	print - print out a listing of px
14
15
16
17Bugs and Limitations:
18
19   Runtime error messages could give far more information than they
20currently do. (eg the actual value of a subscript which is out
21of range)
22
23   It should be possible to resume execution following many of
24the runtime errors. (eg fixed overflow, interrupt, etc)
25
26
27Comparison of Pascal with C compiler
28
29In an attempt to compare compiled versus interpreted execution speeds
30the 'Tower of Hanoi' benchmark (see hanoi.p, hanoi.c) was run with
31the following results:
32
33Data:
34	number of disks: 		   16
35	number of moves required:	65535
36
37Compiler, Flags		  Compile	Compile		 Run	 Run
38			   Time		 Factor		 Time	Factor
39Pi, full tests		 0.4u+0.4s	  1.0		42.7u	  1.0
40Pi, no tests		 0.3u+0.3s	  0.7		35.2u	  1.2
41Pc, unoptimized		 3.8u+2.4s	  7.7		 5.3u	  8.1
42Pc, optimized		 4.4u+2.3s	  8.4		 4.6u	  9.3
43C, unoptimized		 1.7u+1.8s	  4.4		 2.8u	 15.3
44C, optimized		 2.0u+2.0s	  5.0		 2.5u	 17.1
45
46Note: The times for Pc and C were obtained by running larger
47problems and scaling the run times down appropriately.
48