Programmer 7500/MAX_PROGRAMMERS.iso/PASCAL/BPL70N12.ZIP/README.DOC

Text File | 1993-05-20 | 17.8 KB | 348 lines

     Borland-Pascal 7.0 Runtime Libary Update - Release 1.2   05-20-1993


     Welcome to BPL70N12.ZIP, a collection of fast replacement libraries
     for your Turbo Pascal 7.0 / Borland Pascal 7.0 compiler. There are
     three libraries in this package, a real mode library (TURBO.TPL), a
     DOS protected mode library (TPP.TPL), and a Windows library (TPW.TPL).
     Every file is a complete replacement for the original library bearing
     the same name that came with your Pascal compiler. Due to the many
     optimizations in the replacement libraries, many programs compiled
     with these libraries will run faster. For more detailed information
     on possible performance improvements, see the file PERFORM.DOC. Only
     performance information for real mode and DOS protected mode programs
     can be provided at the moment.

     Those users already familiar with my previous project, the fast
     replacement library for Turbo Pascal 6.0 (distributed as TPL60N19.ZIP),
     may be disappointed that not all the features of that program have
     been included in BPL70N12.ZIP yet. I don't have much time at the moment,
     but still wanted to provide a BP 7.0 version of my library as soon as
     possible. So I decided to port the performance relevant stuff first
     and work on the other aspects later.

     The libaries in BPL70N12 maintain 99.9% compatibility with the original
     libraries. Differences are mostly caused by bug fixes and enhancements.
     Some bugs from the original libraries supplied by Borland have been
     eliminated, but there can be no guarantee that new ones have not crept
     in. Most of the code in the BPL70N12.ZIP libraries was ported from the
     latest version of my fast replacement library for Turbo Pascal 6.0,
     TPL60N19.ZIP, which has been proven to be a stable and reliable product.

     If you discover any bugs, or have other comments, please let me know.
     My email and snail mail addresses are given below. Although I am under
     severe time constraints, I will try as hard as possible to fix any bugs
     reported in as short a time as possible.

     The legal conditions under which Borland is distributing the source code
     of the Borland Pascal 7.0 run-time libraries are not entirely clear to me.
     To stay on the safe side, I assume that they are the same as for the RTL
     source for the TP 6.0 compiler. Under these conditions, I am not allowed
     to distribute modified source modules from the library. I may only
     provide the binaries to third parties. However, some of the modules in
     the BPL70N12.ZIP libaries do not contain a single line of code written
     by Borland and are written entirely by me. I am including the source for
     these modules for your reference. The source of the arithmetic routines
     can be found in the file ARISOURC.ZIP. The source code of most of the
     string routines is contained in the file STRSOURC.ZIP. The code of the
     arithmetic and string routines is hereby released into the public domain.
     You may use it in your own programs under the condition that you do not
     include it into a commercial product. Parties interested in commercial
     use of my code should contact me at my address below.


     Original library code is Copyright (C) 1983,92 Borland International


     New / additional library code is Copyright (C) 1988-1993

     Norbert Juffa, Wielandtstr. 14, 7500 Karlsruhe 1, Germany
     Internet: [e-mail]



     Contents of this document:

     I.   Capabilities of RTL replacement
     II.  Revision History
     III. References



     I. Capabilities of RTL replacement
     ==================================


     General note:

     BPL70N12 provides you with optimized libraries, it does not enhance
     the code produced by the Borland Pascal compiler. Thus, only code
     that uses many library calls can be expected to experience significant
     performance advantages. Library calls are made by BP 7.0 to operate
     on LONGINTs, STRINGs, REALs, SETs, perform heap operations such as
     allocating and deallocating memory (New, Dispose, GetMem, FreeMem),
     as well as to perform other tasks. One exception where BPL70N10 speeds
     up your code although no calls to optimized library routines are
     made is floating-point applications using a 287 or 387 coprocessor.

     If want to speed up your applications even further than can be
     accomplished by using BPL70N12, you might want to look at the
     "Sally TPU peephole optimizer" (SPO for short) written by Morten
     Welinder ([e-mail]). Unlike BPL70N12, this program is not in
     the public domain, but Morten grants free use of the program for
     personal, non-commercial use during all of 1993. SPO is a peephole
     optimizer that aims at optimizing the code produced by the Pascal
     compiler. Peephole optimizations means that the optimizer looks at
     a rather small collection of machine instructions at a time and
     replaces certain sequences it finds with optimized code. A TPU-optimizer
     speeds up those parts of a program that can't be enhanced by a
     replacement library and vice versa. So it might be a good idea to
     combine both tools to get the best performance out of your BP 7.0
     programs. The SPO optimizer is currently distributed as a file
     SPO110.ZIP, with the next version most likely going to be called
     SPO120.ZIP. It should be available from all ftp-sites that carry
     BPL70N12 and in particular can be downloaded from garbo.uwasa.fi,
     which is the upload site for the program. Please note that this is
     not intended to be an endorsement of the program. Rather, the info
     provided should be thought of as being a service to those users of
     BPL70N12 who want to speed up their programs even further than
     possible by using BPL70N12.


     Improvements in SYSTEM module
     -----------------------------

o    REAL type software arithmetic operations now comply with ANSI/IEEE
     Standard 754-1985 for Binary Floating Point Arithmetic [1,2] as much
     as possible. Note that REAL arithmetic by design differs from the
     standard in many ways, especially available numeric formats, value
     set, and available operations. The rounding mode implemented here
     is "round to nearest or even" as specified by the standard. Add,
     Subtract, Multiply, Squaring, Division, and Square Root deliver
     exact results with regard to this rounding mode, as demanded by the
     standard. Conversions from REAL to LONGINT and from EXTENDED to REAL
     use rounding to nearest or even, as specified in the standard. Correct
     implementation of above features was tested with the PARANOIA test
     program [3]. The correctness of basic REAL arithmetic functions has
     also been tested against the coprocessor/emulator EXTENDED format
     with the program FUN1_TST. The EXTENDED format carries approximately
     19 decimal digits of precision. This description applies to all three
     libraries in the package.

o    REAL arithmetic operations have been sped up. Speed-up for SQRT varies
     between a factor of 11 for a 8086 and 30 for a 486DLC. FRAC now executes
     at twice the original speed and speed-up is between 50% and 100% for
     SIN, COS, ARCTAN, LN, EXP and division (2.8x speed up for division on
     80386). Overall numeric processing power using REAL arithmetic increases
     by about 52% for an 8086 and by 85% for an Cyrix 486DLC as measured
     by the WHETSTONE benchmark [4,5]. This description applies to all three
     libraries, but the actual values cited are for the real mode library
     TURBO.TPL and may be different for the other libraries. In general,
     DOS protected mode and Windows programs tend to be slower than real mode
     programs by 5-50%.

o    Overall accuracy of REAL arithmetic transcendental functions has been
     improved as indicated by Cody&Waite's ELEFUNT tests [6]: DLOG, DEXP,
     DATAN, DSIN. Correct argument reduction ensures that relative error
     over the whole argument range does not exceed 1.9e-12 for Exp, 2.8e-12
     for Arctan, and 2.7e-12 for Ln. These values have been determined
     by comparing the function returns of the REAL transcendental functions
     to the values computed on a Cyrix 83D87 coprocessor for the EXTENDED
     format. For Sin and Cos, relative error is also in the above range
     when the argument is reasonably small (e.g. in range -100..100) and
     not very close to an integer multiple of 0.25*Pi. The error of the
     transcendental functions expressed in ULPs (units in the last place)
     over the whole argument range does not exceed 1.6 ULPs for Exp, 1.8
     ULPs for Arctan, and 2.2 ULPs for Ln. This description applies to all
     three libraries in the package.

o    Execution of coprocessor floating point computations using an 80287 or
     80387 has been accelerated. For these coprocessors, NOPs will be inserted
     before every floating point instruction converted from an emulator
     interrupt instead of WAITs. As a result of this optimization, an
     improvement in execution speed of about 10% has been observed running the
     Lawrence Livermore Loops (LLL) [7] on a Cyrix 83D87, the improvement
     for the WHETSTONE benchmark on the 83D87 is similar. Maximum performance
     gain for tight loops (e.g. fractal computation) by this measure is about
     22%.

o    On 80287XL, 80387, 80486DX, or compatible chips the Sin and Cos functions
     take advantage of the FSIN and FCOS instructions of these coprocessors,
     speeding up these functions by almost a factor of two. As a side effect,
     there is also some improvement in accuracy as measured by the DSIN test
     program from the ELEFUNT test suite. Also, the Arctan function takes
     advantage of the increased argument range of the FPATAN function. These
     optimizations result in another 19% increase in WHETSTONE power, so
     that the total combined speedup over the original library is about 30%
     for this benchmark using a 387 coprocessor.

o    STRING operations are faster, especially for longer strings. Most
     dramatic increase is in the INSERT function, with execution times
     reduced to up to one fourth compared with the original version of
     the RTL. Faster string operations cause 7% performance increase for
     the DHRYSTONE [8,9] benchmark on a 8086.

o    Improved speed of random number generation. Random for REAL numbers
     is 10-20% faster, Random for EXTENDED numbers is 5% faster. Due to
     the improvements in the uniform distribution of integer random numbers,
     there is a decrease in the speed of integer random number generation
     of about 5%.

o    Binary to decimal conversions used in Str and Write procedures have
     been sped up by up to 70% for integers (BYTE, SHORTINT, INTEGER,
     WORD, LONGINT), up to 5% for REAL numbers and about 3% for EXTENDED
     numbers.

o    Improved speed of LONGINT arithmetic for 8086..80286. Division enjoys
     a 30% reduction of execution time on 8086. On 386 and 486 type CPUs,
     the code used in BPL70N12 may be slower than that used by the original
     library, which uses 32 bit register operations, while BPL70N12 uses
     only 16 bit operations, however very cleverly. For most applications
     you will not note any drop in LONGINT performance on 386/486 machines
     by using BPL70N12.

o    Several of the functions of the heap manager have been tuned, resulting
     in 7%-11% faster operation for these routines, depending on the CPU used.
     This note applies only to the real mode heap manager in TURBO.TPL!

o    Set functions have been sped up by a few percent, but the add variable
     range operation may be up to eight times as fast.

o    UPCASE function has been enhanced to support the complete IBM character
     set. This means that characters ä,ü,ö,å,æ,é,ñ,ç are converted to upper
     case by this function.

o    Several bugs of the original RTL supplied by Borland have been fixed:

     The original routines to perform LONGINT shifts provide the wrong results
     when the program runs on a 386 or 486 type processor and the shift count
     exceeds 16. This has been fixed by replacing all LONGINT routines with
     my own code. My code doesn't use 386 specific instructions and foregoes
     the speed advantage offered by using 32-bit register operations. For all
     programs but a very few you will not notice any drop in performance on a
     386-486 machine, though.

     GetDir now correctly returns a run-time error 15 (invalid drive)
     when called with a non existent drive. Differing from the original,
     it also signals all errors reported by DOS as run-time errors. E.g.
     when applied to a floppy drive that does not contain a floppy, it
     will now return run-time error 152 (drive not ready), where previously
     it would incorrectly signal successful completion of the operation
     (InOutRes = 0).

     For programs compiled with $N+, only true INFs are printed out as
     INF where with the original library some NaNs are also printed as
     INF. Correct operation can be tested with the INFBUG program.

     REAL arithmetic EXP functions no longer signals overflow when
     called with small arguments, but underflows to zero instead as it
     should.

     Denormals in EXTENDED computations no longer cause an invalid state
     on a 8087 coprocessor when being converted to true zeros. Consistency
     between register contents and tag bits is now asserted. Removal of
     this bug can be tested with the BUG87 program.

     Denormals in EXTENDED format are now correctly converted to decimal
     strings by the Str and Write routines. The original routines print
     EXTENDED precision denormals as zero. Note that BP 7.0 supports
     EXTENDED denormals only if your machine has an 80287XL, 80387, 80486
     or equivalent. On the 8087 and Intel's original 80287 coprocessor
     denormals are only supported for the SINGLE and DOUBLE formats. Correct
     printing of extended precision denormals can be checked with the
     program DENORMTS.

     Program initialization routine now tries to prevent that programs
     compiled with the $G+ (286 code generation) switch are run on 8086
     and 8088. The checks done are not 100% safe, but catch most of these
     cases, displaying the message "CPU > 8086 required" and aborting the
     program with a return code of 254 ($FE) instead of letting it crash.
     Note that this check lets programs compiled with $G+ run on 80186 and
     V20/V30 processors, since they have the ability to execute all 80286
     real mode instructions produced by Turbo Pascal. This note applies
     only to real mode programs, as DOS protected mode and Windows programs
     will not run on anything less than a 286 anyhow.



     Improvements in CRT module
     --------------------------

o    Bug fix in routine DirectWrite. The method used to prevent "snow"
     when writing directly to a CGA graphics card was not entirely safe.
     When used in a heavily interrupted program (e.g. serial communication
     as a background task), it would not always write during the time
     when scanning was in the invisible parts of the screen. The method
     used now is 100% save and is even faster, since it takes advantage
     of the horizontal and vertical retrace periods, as opposed to the
     old method which only used the horizontal retrace time. The new
     routine has been tested successfully on an original IBM-CGA card.



     II. Revision History
     ====================

     Changes since Version 1.1, dated 03-15-1993

o    Fixed bug in the Write and WriteLn routines of the CRT unit. Due to
     this bug, these routines could not function properly on a Hercules
     Graphics Card or other monochrome display. Thanks to Miha Vitorovic
     ([e-mail]) for reporting this bug.


     Changes since Version 1.0, dated 03-10-1993

o    Fixed bug in LONGINT and REAL Val routine. Val erroneously returned
     the wrong value or an error code for syntactically correct strings.
     Thanks to Dennis J. Basiaga ([e-mail]), who was
     the first to report this bug.


     Version 1.0, original release.



     III. References
     ===============

[1]  IEEE: IEEE Standard for Binary Floating-Point Arithmetic.
     SIGPLAN Notices, Vol. 22, No. 2, 1985, pp. 9-25

[2]  IEEE Standard for Binary Floating-Point Arithmetic.
     ANSI/IEEE Std 754-1985.
     New York, NY: Institute of Electrical and Electronics Engineers 1985

[3]  Karpinski, R.: Paranoia: A Floating-Point Benchmark.
     Byte, February 1985, pp. 223-235

[4]  Curnow, H.J.; Wichmann, B.A.: A synthetic benchmark.
     Computer Journal, Vol. 19, No. 1, 1976, pp. 43-49

[5]  Wichmannn, B.A.: Validation code for the Whetstone benchmark.
     NPL Report DITC 107/88, National Physics Laboratory, UK, March 1988

[6]  Cody, W.J.; Waite, W.: Software Manual for the Elementary Functions.
     Englewood Cliffs, NJ: Prentice Hall 1980

[7]  McMahon, H.H.: The Livermore Fortran Kernels: A Test of the Numerical
     Performance Range.
     Technical Report UCRL-53745, Lawrence Livermore National Laboratory,
     December 1986, p. 179

[8]  Weicker, R.P.: Dhrystone: A Synthetic Systems Programming Benchmark.
     Communications of the ACM, Vol. 27, No. 10, October 1984, pp. 1013-1030

[9]  Weicker, R.P.: Dhrystone Benchmark: Rationale for Version 2 and
     Measurement Rules.
     SIGPLAN Notices, Vol. 23, No. 8, August 1988, pp. 49-62

[10] 387DX User's Manual, Programmer's Reference. Intel 1989


     Note:

     PARANOIA, DHRYSTONE, WHETSTONE, LLL, and ELEFUNT source code is
     available from [e-mail]