xref: /csrg-svn/usr.bin/pascal/px/READ_ME (revision 62241)
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32078Smckusick   This directory contains the source code for the Version 7 VAX
42078Smckusickinterpreter for Pascal. Following standard convensions, the makefile
52078Smckusickcontains four commands:
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72078Smckusick	px - compile px
82078Smckusick
92078Smckusick	install - compile and install px in /usr/ucb
102078Smckusick
112078Smckusick	clean - clean out directory
122078Smckusick
132078Smckusick	print - print out a listing of px
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172078SmckusickBugs and Limitations:
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192078Smckusick   Runtime error messages could give far more information than they
202078Smckusickcurrently do. (eg the actual value of a subscript which is out
212078Smckusickof range)
222078Smckusick
232078Smckusick   It should be possible to resume execution following many of
242078Smckusickthe runtime errors. (eg fixed overflow, interrupt, etc)
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272078SmckusickComparison of Pascal with C compiler
282078Smckusick
292078SmckusickIn an attempt to compare compiled versus interpreted execution speeds
302078Smckusickthe 'Tower of Hanoi' benchmark (see hanoi.p, hanoi.c) was run with
312078Smckusickthe following results:
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332078SmckusickData:
342078Smckusick	number of disks: 		   16
352078Smckusick	number of moves required:	65535
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372078SmckusickCompiler, Flags		  Compile	Compile		 Run	 Run
382078Smckusick			   Time		 Factor		 Time	Factor
392078SmckusickPi, full tests		 0.4u+0.4s	  1.0		42.7u	  1.0
402078SmckusickPi, no tests		 0.3u+0.3s	  0.7		35.2u	  1.2
412078SmckusickPc, unoptimized		 3.8u+2.4s	  7.7		 5.3u	  8.1
422078SmckusickPc, optimized		 4.4u+2.3s	  8.4		 4.6u	  9.3
432078SmckusickC, unoptimized		 1.7u+1.8s	  4.4		 2.8u	 15.3
442078SmckusickC, optimized		 2.0u+2.0s	  5.0		 2.5u	 17.1
452078Smckusick
462078SmckusickNote: The times for Pc and C were obtained by running larger
472078Smckusickproblems and scaling the run times down appropriately.
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