| 1 | Copyright (c) 1979 Regents of the University of California |
| 2 | |
| 3 | sccsid = "@(#)READ_ME 1.1 %G%" |
| 4 | |
| 5 | This directory contains the source code for the Version 7 VAX |
| 6 | interpreter for Pascal. Following standard convensions, the makefile |
| 7 | contains four commands: |
| 8 | |
| 9 | px - compile px |
| 10 | |
| 11 | install - compile and install px in /usr/ucb |
| 12 | |
| 13 | clean - clean out directory |
| 14 | |
| 15 | print - print out a listing of px |
| 16 | |
| 17 | |
| 18 | |
| 19 | Bugs and Limitations: |
| 20 | |
| 21 | Runtime error messages could give far more information than they |
| 22 | currently do. (eg the actual value of a subscript which is out |
| 23 | of range) |
| 24 | |
| 25 | It should be possible to resume execution following many of |
| 26 | the runtime errors. (eg fixed overflow, interrupt, etc) |
| 27 | |
| 28 | |
| 29 | Comparison of Pascal with C compiler |
| 30 | |
| 31 | In an attempt to compare compiled versus interpreted execution speeds |
| 32 | the 'Tower of Hanoi' benchmark (see hanoi.p, hanoi.c) was run with |
| 33 | the following results: |
| 34 | |
| 35 | Data: |
| 36 | number of disks: 16 |
| 37 | number of moves required: 65535 |
| 38 | |
| 39 | Compiler, Flags Compile Compile Run Run |
| 40 | Time Factor Time Factor |
| 41 | Pi, full tests 0.4u+0.4s 1.0 42.7u 1.0 |
| 42 | Pi, no tests 0.3u+0.3s 0.7 35.2u 1.2 |
| 43 | Pc, unoptimized 3.8u+2.4s 7.7 5.3u 8.1 |
| 44 | Pc, optimized 4.4u+2.3s 8.4 4.6u 9.3 |
| 45 | C, unoptimized 1.7u+1.8s 4.4 2.8u 15.3 |
| 46 | C, optimized 2.0u+2.0s 5.0 2.5u 17.1 |
| 47 | |
| 48 | Note: The times for Pc and C were obtained by running larger |
| 49 | problems and scaling the run times down appropriately. |