projects / unix-history / blame
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1 | /*- |
| 2 | * Copyright (c) 1980 The Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * %sccs.include.redist.c% | |
| 6 | * | |
| 7 | * @(#)READ_ME 5.2 (Berkeley) %G% | |
| 8 | */ | |
| f051ea27 KM |
9 | |
| 10 | This directory contains the source code for the Version 7 VAX | |
| 11 | interpreter for Pascal. Following standard convensions, the makefile | |
| 12 | contains four commands: | |
| 13 | ||
| 14 | px - compile px | |
| 15 | ||
| 16 | install - compile and install px in /usr/ucb | |
| 17 | ||
| 18 | clean - clean out directory | |
| 19 | ||
| 20 | print - print out a listing of px | |
| 21 | ||
| 22 | ||
| 23 | ||
| 24 | Bugs and Limitations: | |
| 25 | ||
| 26 | Runtime error messages could give far more information than they | |
| 27 | currently do. (eg the actual value of a subscript which is out | |
| 28 | of range) | |
| 29 | ||
| 30 | It should be possible to resume execution following many of | |
| 31 | the runtime errors. (eg fixed overflow, interrupt, etc) | |
| 32 | ||
| 33 | ||
| 34 | Comparison of Pascal with C compiler | |
| 35 | ||
| 36 | In an attempt to compare compiled versus interpreted execution speeds | |
| 37 | the 'Tower of Hanoi' benchmark (see hanoi.p, hanoi.c) was run with | |
| 38 | the following results: | |
| 39 | ||
| 40 | Data: | |
| 41 | number of disks: 16 | |
| 42 | number of moves required: 65535 | |
| 43 | ||
| 44 | Compiler, Flags Compile Compile Run Run | |
| 45 | Time Factor Time Factor | |
| 46 | Pi, full tests 0.4u+0.4s 1.0 42.7u 1.0 | |
| 47 | Pi, no tests 0.3u+0.3s 0.7 35.2u 1.2 | |
| 48 | Pc, unoptimized 3.8u+2.4s 7.7 5.3u 8.1 | |
| 49 | Pc, optimized 4.4u+2.3s 8.4 4.6u 9.3 | |
| 50 | C, unoptimized 1.7u+1.8s 4.4 2.8u 15.3 | |
| 51 | C, optimized 2.0u+2.0s 5.0 2.5u 17.1 | |
| 52 | ||
| 53 | Note: The times for Pc and C were obtained by running larger | |
| 54 | problems and scaling the run times down appropriately. |