--- gforth/Attic/gforth.ds 1995/09/15 14:52:51 1.17 +++ gforth/Attic/gforth.ds 1996/02/09 17:34:09 1.31 @@ -7,9 +7,9 @@ @comment %**end of header (This is for running Texinfo on a region.) @ifinfo -This file documents Gforth 0.1 +This file documents Gforth 0.2 -Copyright @copyright{} 1994 Gforth Development Group +Copyright @copyright{} 1995 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice @@ -36,20 +36,22 @@ Copyright @copyright{} 1994 Gforth Devel of in the original English. @end ifinfo +@finalout @titlepage @sp 10 @center @titlefont{Gforth Manual} @sp 2 -@center for version 0.1 +@center for version 0.2 @sp 2 @center Anton Ertl +@center Bernd Paysan @sp 3 @center This manual is under construction @comment The following two commands start the copyright page. @page @vskip 0pt plus 1filll -Copyright @copyright{} 1994 Gforth Development Group +Copyright @copyright{} 1995 Free Software Foundation, Inc. @comment !! Published by ... or You can get a copy of this manual ... @@ -75,7 +77,7 @@ Copyright @copyright{} 1994 Gforth Devel @node Top, License, (dir), (dir) @ifinfo Gforth is a free implementation of ANS Forth available on many -personal machines. This manual corresponds to version 0.0. +personal machines. This manual corresponds to version 0.2. @end ifinfo @menu @@ -89,17 +91,408 @@ personal machines. This manual correspon * Emacs and Gforth:: The Gforth Mode * Internals:: Implementation details * Bugs:: How to report them -* Pedigree:: Ancestors of Gforth +* Origin:: Authors and ancestors of Gforth * Word Index:: An item for each Forth word * Node Index:: An item for each node @end menu @node License, Goals, Top, Top -@unnumbered License -!! Insert GPL here +@unnumbered GNU GENERAL PUBLIC LICENSE +@center Version 2, June 1991 + +@display +Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc. +675 Mass Ave, Cambridge, MA 02139, USA + +Everyone is permitted to copy and distribute verbatim copies +of this license document, but changing it is not allowed. +@end display + +@unnumberedsec Preamble + + The licenses for most software are designed to take away your +freedom to share and change it. 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SHOULD THE +PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, +REPAIR OR CORRECTION. + +@item +IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR +REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, +INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING +OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED +TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY +YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER +PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE +POSSIBILITY OF SUCH DAMAGES. +@end enumerate @iftex +@heading END OF TERMS AND CONDITIONS +@end iftex +@ifinfo +@center END OF TERMS AND CONDITIONS +@end ifinfo + +@page +@unnumberedsec How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. It is safest +to attach them to the start of each source file to most effectively +convey the exclusion of warranty; and each file should have at least +the ``copyright'' line and a pointer to where the full notice is found. + +@smallexample +@var{one line to give the program's name and a brief idea of what it does.} +Copyright (C) 19@var{yy} @var{name of author} + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or +(at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program; if not, write to the Free Software +Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +@end smallexample + +Also add information on how to contact you by electronic and paper mail. + +If the program is interactive, make it output a short notice like this +when it starts in an interactive mode: + +@smallexample +Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author} +Gnomovision comes with ABSOLUTELY NO WARRANTY; for details +type `show w'. +This is free software, and you are welcome to redistribute it +under certain conditions; type `show c' for details. +@end smallexample + +The hypothetical commands @samp{show w} and @samp{show c} should show +the appropriate parts of the General Public License. Of course, the +commands you use may be called something other than @samp{show w} and +@samp{show c}; they could even be mouse-clicks or menu items---whatever +suits your program. + +You should also get your employer (if you work as a programmer) or your +school, if any, to sign a ``copyright disclaimer'' for the program, if +necessary. Here is a sample; alter the names: + +@smallexample +Yoyodyne, Inc., hereby disclaims all copyright interest in the program +`Gnomovision' (which makes passes at compilers) written by James Hacker. + +@var{signature of Ty Coon}, 1 April 1989 +Ty Coon, President of Vice +@end smallexample + +This General Public License does not permit incorporating your program into +proprietary programs. If your program is a subroutine library, you may +consider it more useful to permit linking proprietary applications with the +library. If this is what you want to do, use the GNU Library General +Public License instead of this License. + +@iftex +@node Preface +@comment node-name, next, previous, up @unnumbered Preface +@cindex Preface This manual documents Gforth. The reader is expected to know Forth. This manual is primarily a reference manual. @xref{Other Books} for introductory material. @@ -157,12 +550,19 @@ not written for ANS Forth, as you will n deviations of the book. There is, of course, the standard, the definite reference if you want to -write ANS Forth programs. It will be available in printed form from -Global Engineering Documents !! somtime in spring or summer 1994. If you -are lucky, you can still get dpANS6 (the draft that was approved as -standard) by aftp from ftp.uu.net:/vendor/minerva/x3j14. +write ANS Forth programs. It is available in printed form from the +National Standards Institute Sales Department (Tel.: USA (212) 642-4900; +Fax.: USA (212) 302-1286) as document @cite{X3.215-1994} for about $200. You +can also get it from Global Engineering Documents (Tel.: USA (800) +854-7179; Fax.: (303) 843-9880) for about $300. + +@cite{dpANS6}, the last draft of the standard, which was then submitted to ANSI +for publication is available electronically and for free in some MS Word +format, and it has been converted to HTML. Some pointers to these +versions can be found through +@*@file{http://www.complang.tuwien.ac.at/projects/forth.html}. -@cite{Forth: The new model} by Jack Woehr (!! Publisher) is an +@cite{Forth: The new model} by Jack Woehr (Prentice-Hall, 1993) is an introductory book based on a draft version of the standard. It does not cover the whole standard. It also contains interesting background information (Jack Woehr was in the ANS Forth Technical Committe). It is @@ -193,10 +593,12 @@ line. They are: @table @code @item --image-file @var{file} +@item -i @var{file} Loads the Forth image @var{file} instead of the default @file{gforth.fi}. @item --path @var{path} +@item -p @var{path} Uses @var{path} for searching the image file and Forth source code files instead of the default in the environment variable @code{GFORTHPATH} or the path specified at installation time (typically @@ -245,6 +647,12 @@ Forth words, you have to quote them or u after processing the command line (instead of entering interactive mode) append @code{-e bye} to the command line. +If you have several versions of Gforth installed, @code{gforth} will +invoke the version that was installed last. @code{gforth-@var{version}} +invokes a specific version. You may want to use the option +@code{--path}, if your environment contains the variable +@code{GFORTHPATH}. + Not yet implemented: On startup the system first executes the system initialization file (unless the option @code{--no-init-file} is given; note that the system @@ -269,6 +677,7 @@ then in @file{~}, then in the normal pat * Blocks:: * Other I/O:: * Programming Tools:: +* Assembler and Code words:: * Threading Words:: @end menu @@ -300,6 +709,13 @@ effect}, but in @var{Description}. The n the type and/or the function of the item. See below for a discussion of the types. +All words have two stack effects: A compile-time stack effect and a +run-time stack effect. The compile-time stack-effect of most words is +@var{ -- }. If the compile-time stack-effect of a word deviates from +this standard behaviour, or the word does other unusual things at +compile time, both stack effects are shown; otherwise only the run-time +stack effect is shown. + @item pronunciation How the word is pronounced @@ -309,7 +725,11 @@ system need not support all of them. So, uses the more portable it will be in theory. However, we suspect that most ANS Forth systems on personal machines will feature all wordsets. Words that are not defined in the ANS standard have -@code{gforth} as wordset. +@code{gforth} or @code{gforth-internal} as wordset. @code{gforth} +describes words that will work in future releases of Gforth; +@code{gforth-internal} words are more volatile. Environmental query +strings are also displayed like words; you can recognize them by the +@code{environment} in the wordset field. @item Description A description of the behaviour of the word. @@ -721,8 +1141,11 @@ system that only supplies @code{THEN} is Forth's @code{THEN} has the meaning 2b, whereas @code{THEN} in Pascal and many other programming languages has the meaning 3d.] -We also provide the words @code{?dup-if} and @code{?dup-0=-if}, so you -can avoid using @code{?dup}. +Gforth also provides the words @code{?dup-if} and @code{?dup-0=-if}, so +you can avoid using @code{?dup}. Using these alternatives is also more +efficient than using @code{?dup}. Definitions in plain standard Forth +for @code{ENDIF}, @code{?DUP-IF} and @code{?DUP-0=-IF} are provided in +@file{compat/control.fs}. @example @var{n} @@ -808,13 +1231,21 @@ There are several variations on the coun @code{LEAVE} leaves the innermost counted loop immediately. +If @var{start} is greater than @var{limit}, a @code{?DO} loop is entered +(and @code{LOOP} iterates until they become equal by wrap-around +arithmetic). This behaviour is usually not what you want. Therefore, +Gforth offers @code{+DO} and @code{U+DO} (as replacements for +@code{?DO}), which do not enter the loop if @var{start} is greater than +@var{limit}; @code{+DO} is for signed loop parameters, @code{U+DO} for +unsigned loop parameters. + @code{LOOP} can be replaced with @code{@var{n} +LOOP}; this updates the index by @var{n} instead of by 1. The loop is terminated when the border between @var{limit-1} and @var{limit} is crossed. E.g.: -@code{4 0 ?DO i . 2 +LOOP} prints @code{0 2} +@code{4 0 +DO i . 2 +LOOP} prints @code{0 2} -@code{4 1 ?DO i . 2 +LOOP} prints @code{1 3} +@code{4 1 +DO i . 2 +LOOP} prints @code{1 3} The behaviour of @code{@var{n} +LOOP} is peculiar when @var{n} is negative: @@ -822,23 +1253,28 @@ The behaviour of @code{@var{n} +LOOP} is @code{ 0 0 ?DO i . -1 +LOOP} prints nothing -Therefore we recommend avoiding using @code{@var{n} +LOOP} with negative -@var{n}. One alternative is @code{@var{n} S+LOOP}, where the negative -case behaves symmetrical to the positive case: - -@code{-2 0 ?DO i . -1 S+LOOP} prints @code{0 -1} - -@code{-1 0 ?DO i . -1 S+LOOP} prints @code{0} - -@code{ 0 0 ?DO i . -1 S+LOOP} prints nothing - -The loop is terminated when the border between @var{limit@minus{}sgn(n)} and -@var{limit} is crossed. However, @code{S+LOOP} is not part of the ANS -Forth standard. - -@code{?DO} can be replaced by @code{DO}. @code{DO} enters the loop even -when the start and the limit value are equal. We do not recommend using -@code{DO}. It will just give you maintenance troubles. +Therefore we recommend avoiding @code{@var{n} +LOOP} with negative +@var{n}. One alternative is @code{@var{u} -LOOP}, which reduces the +index by @var{u} each iteration. The loop is terminated when the border +between @var{limit+1} and @var{limit} is crossed. Gforth also provides +@code{-DO} and @code{U-DO} for down-counting loops. E.g.: + +@code{-2 0 -DO i . 1 -LOOP} prints @code{0 -1} + +@code{-1 0 -DO i . 1 -LOOP} prints @code{0} + +@code{ 0 0 -DO i . 1 -LOOP} prints nothing + +Unfortunately, @code{+DO}, @code{U+DO}, @code{-DO}, @code{U-DO} and +@code{-LOOP} are not in the ANS Forth standard. However, an +implementation for these words that uses only standard words is provided +in @file{compat/loops.fs}. + +@code{?DO} can also be replaced by @code{DO}. @code{DO} always enters +the loop, independent of the loop parameters. Do not use @code{DO}, even +if you know that the loop is entered in any case. Such knowledge tends +to become invalid during maintenance of a program, and then the +@code{DO} will make trouble. @code{UNLOOP} is used to prepare for an abnormal loop exit, e.g., via @code{EXIT}. @code{UNLOOP} removes the loop control parameters from the @@ -855,7 +1291,8 @@ This is the preferred loop of native cod lazy to optimize @code{?DO} loops properly. In Gforth, this loop iterates @var{n+1} times; @code{i} produces values starting with @var{n} and ending with 0. Other Forth systems may behave differently, even if -they support @code{FOR} loops. +they support @code{FOR} loops. To avoid problems, don't use @code{FOR} +loops. @node Arbitrary control structures, Calls and returns, Counted Loops, Control Structures @subsection Arbitrary control structures @@ -891,14 +1328,24 @@ doc-else doc-while doc-repeat +Gforth adds some more control-structure words: + +doc-endif +doc-?dup-if +doc-?dup-0=-if + Counted loop words constitute a separate group of words: doc-?do +doc-+do +doc-u+do +doc--do +doc-u-do doc-do doc-for doc-loop -doc-s+loop doc-+loop +doc--loop doc-next doc-leave doc-?leave @@ -961,7 +1408,7 @@ while repeat @end example -That's much easier to read, isn't it? Of course, @code{BEGIN} and +That's much easier to read, isn't it? Of course, @code{REPEAT} and @code{WHILE} are predefined, so in this example it would not be necessary to define them. @@ -995,6 +1442,11 @@ laden with restrictions. Therefore, we p locals wordset, but also our own, more powerful locals wordset (we implemented the ANS Forth locals wordset through our locals wordset). +The ideas in this section have also been published in the paper +@cite{Automatic Scoping of Local Variables} by M. Anton Ertl, presented +at EuroForth '94; it is available at +@*@file{http://www.complang.tuwien.ac.at/papers/ertl94l.ps.gz}. + @menu * Gforth locals:: * ANS Forth locals:: @@ -1281,8 +1733,8 @@ E.g., a definition using @code{TO} might : strcmp @{ addr1 u1 addr2 u2 -- n @} u1 u2 min 0 ?do - addr1 c@ addr2 c@ - ?dup - if + addr1 c@ addr2 c@ - + ?dup-if unloop exit then addr1 char+ TO addr1 @@ -1304,8 +1756,8 @@ are initialized with the right value for addr1 addr2 u1 u2 min 0 ?do @{ s1 s2 @} - s1 c@ s2 c@ - ?dup - if + s1 c@ s2 c@ - + ?dup-if unloop exit then s1 char+ s2 char+ @@ -1484,8 +1936,8 @@ name produces their value. Their value c Since this syntax is supported by Gforth directly, you need not do anything to use it. If you want to port a program using this syntax to -another ANS Forth system, use @file{anslocal.fs} to implement the syntax -on the other system. +another ANS Forth system, use @file{compat/anslocal.fs} to implement the +syntax on the other system. Note that a syntax shown in the standard, section A.13 looks similar, but is quite different in having the order of locals @@ -1526,7 +1978,7 @@ locals wordset. @node Other I/O, Programming Tools, Blocks, Words @section Other I/O -@node Programming Tools, Threading Words, Other I/O, Words +@node Programming Tools, Assembler and Code words, Other I/O, Words @section Programming Tools @menu @@ -1625,7 +2077,75 @@ If there is interest, we will introduce intend to @code{catch} a specific condition, using @code{throw} is probably more appropriate than an assertion). -@node Threading Words, , Programming Tools, Words +@node Assembler and Code words, Threading Words, Programming Tools, Words +@section Assembler and Code words + +Gforth provides some words for defining primitives (words written in +machine code), and for defining the the machine-code equivalent of +@code{DOES>}-based defining words. However, the machine-independent +nature of Gforth poses a few problems: First of all. Gforth runs on +several architectures, so it can provide no standard assembler. What's +worse is that the register allocation not only depends on the processor, +but also on the @code{gcc} version and options used. + +The words that Gforth offers encapsulate some system dependences (e.g., the +header structure), so a system-independent assembler may be used in +Gforth. If you do not have an assembler, you can compile machine code +directly with @code{,} and @code{c,}. + +doc-assembler +doc-code +doc-end-code +doc-;code +doc-flush-icache + +If @code{flush-icache} does not work correctly, @code{code} words +etc. will not work (reliably), either. + +These words are rarely used. Therefore they reside in @code{code.fs}, +which is usually not loaded (except @code{flush-icache}, which is always +present). You can load them with @code{require code.fs}. + +In the assembly code you will want to refer to the inner interpreter's +registers (e.g., the data stack pointer) and you may want to use other +registers for temporary storage. Unfortunately, the register allocation +is installation-dependent. + +The easiest solution is to use explicit register declarations +(@pxref{Explicit Reg Vars, , Variables in Specified Registers, gcc.info, +GNU C Manual}) for all of the inner interpreter's registers: You have to +compile Gforth with @code{-DFORCE_REG} (configure option +@code{--enable-force-reg}) and the appropriate declarations must be +present in the @code{machine.h} file (see @code{mips.h} for an example; +you can find a full list of all declarable register symbols with +@code{grep register engine.c}). If you give explicit registers to all +variables that are declared at the beginning of @code{engine()}, you +should be able to use the other caller-saved registers for temporary +storage. Alternatively, you can use the @code{gcc} option +@code{-ffixed-REG} (@pxref{Code Gen Options, , Options for Code +Generation Conventions, gcc.info, GNU C Manual}) to reserve a register +(however, this restriction on register allocation may slow Gforth +significantly). + +If this solution is not viable (e.g., because @code{gcc} does not allow +you to explicitly declare all the registers you need), you have to find +out by looking at the code where the inner interpreter's registers +reside and which registers can be used for temporary storage. You can +get an assembly listing of the engine's code with @code{make engine.s}. + +In any case, it is good practice to abstract your assembly code from the +actual register allocation. E.g., if the data stack pointer resides in +register @code{$17}, create an alias for this register called @code{sp}, +and use that in your assembly code. + +Another option for implementing normal and defining words efficiently +is: adding the wanted functionality to the source of Gforth. For normal +words you just have to edit @file{primitives}, defining words (for fast +defined words) may require changes in @file{engine.c}, +@file{kernal.fs}, @file{prims2x.fs}, and possibly @file{cross.fs}. + + +@node Threading Words, , Assembler and Code words, Words @section Threading Words These words provide access to code addresses and other threading stuff @@ -1643,7 +2163,20 @@ doc-does-code! doc-does-handler! doc-/does-handler +The code addresses produced by various defining words are produced by +the following words: +doc-docol: +doc-docon: +doc-dovar: +doc-douser: +doc-dodefer: +doc-dofield: + +Currently there is no installation-independent way for recogizing words +defined by a @code{CREATE}...@code{DOES>} word; however, once you know +that a word is defined by a @code{CREATE}...@code{DOES>} word, you can +use @code{>DOES-CODE}. @node ANS conformance, Model, Words, Top @chapter ANS conformance @@ -1670,7 +2203,7 @@ ANS Forth System @item providing the Memory-Allocation word set @item providing the Memory-Allocation Extensions word set (that one's easy) @item providing the Programming-Tools word set -@item providing @code{AHEAD}, @code{BYE}, @code{CS-PICK}, @code{CS-ROLL}, @code{STATE}, @code{[ELSE]}, @code{[IF]}, @code{[THEN]} from the Programming-Tools Extensions word set +@item providing @code{;code}, @code{AHEAD}, @code{ASSEMBLER}, @code{BYE}, @code{CODE}, @code{CS-PICK}, @code{CS-ROLL}, @code{STATE}, @code{[ELSE]}, @code{[IF]}, @code{[THEN]} from the Programming-Tools Extensions word set @item providing the Search-Order word set @item providing the Search-Order Extensions word set @item providing the String word set @@ -1881,7 +2414,7 @@ characters is determined by the locale y @item division rounding: installation dependent. @code{s" floored" environment? drop .}. We leave -the choice to gcc (what to use for @code{/}) and to you (whether to use +the choice to @code{gcc} (what to use for @code{/}) and to you (whether to use @code{fm/mod}, @code{sm/rem} or simply @code{/}). @item values of @code{STATE} when true: @@ -1992,9 +2525,14 @@ The next invocation of a parsing word re Compiles a recursive call to the defining word not to the defined word. @item argument input source different than current input source for @code{RESTORE-INPUT}: -!!???If the argument input source is a valid input source then it gets -restored. Otherwise causes @code{-12 THROW} which unless caught issues -the message "argument type mismatch" and aborts. +@code{-12 THROW}. Note that, once an input file is closed (e.g., because +the end of the file was reached), its source-id may be +reused. Therefore, restoring an input source specification referencing a +closed file may lead to unpredictable results instead of a @code{-12 +THROW}. + +In the future, Gforth may be able to retore input source specifications +from other than the current input soruce. @item data space containing definitions gets de-allocated: Deallocation with @code{allot} is not checked. This typically resuls in @@ -2066,14 +2604,17 @@ Not checked. As usual, you can expect me None. @item operator's terminal facilities available: -!!?? +After processing the command line, Gforth goes into interactive mode, +and you can give commands to Gforth interactively. The actual facilities +available depend on how you invoke Gforth. @item program data space available: @code{sp@ here - .} gives the space remaining for dictionary and data stack together. @item return stack space available: -!!?? +By default 16 KBytes. The default can be overridden with the @code{-r} +switch (@pxref{Invocation}) when Gforth starts up. @item stack space available: @code{sp@ here - .} gives the space remaining for dictionary and data @@ -2394,7 +2935,10 @@ System dependent; @code{REPRESENT} is im function @code{ecvt()} and inherits its behaviour in this respect. @item rounding or truncation of floating-point numbers: -What's the question?!! +System dependent; the rounding behaviour is inherited from the hosting C +compiler. IEEE-FP-based (i.e., most) systems by default round to +nearest, and break ties by rounding to even (i.e., such that the last +bit of the mantissa is 0). @item size of floating-point stack: @code{s" FLOATING-STACK" environment? drop .}. Can be changed at startup @@ -2696,7 +3240,10 @@ Also, if you @code{include} @file{etags. contains the definitions of all words defined afterwards. You can then find the source for a word using @kbd{M-.}. Note that emacs can use several tags files at the same time (e.g., one for the Gforth sources -and one for your program). +and one for your program, @pxref{Select Tags Table,,Selecting a Tags +Table,emacs, Emacs Manual}). The TAGS file for the preloaded words is +@file{$(datadir)/gforth/$(VERSION)/TAGS} (e.g., +@file{/usr/local/share/gforth/0.2/TAGS}). To get all these benefits, add the following lines to your @file{.emacs} file: @@ -2712,6 +3259,12 @@ file: Reading this section is not necessary for programming with Gforth. It should be helpful for finding your way in the Gforth sources. +The ideas in this section have also been published in the papers +@cite{ANS fig/GNU/??? Forth} (in German) by Bernd Paysan, presented at +the Forth-Tagung '93 and @cite{A Portable Forth Engine} by M. Anton +Ertl, presented at EuroForth '93; the latter is available at +@*@file{http://www.complang.tuwien.ac.at/papers/ertl93.ps.Z}. + @menu * Portability:: * Threading:: @@ -3099,32 +3652,38 @@ Sieve benchmark on a 486DX2/66 than Gfor However, this potential advantage of assembly language implementations is not necessarily realized in complete Forth systems: We compared -Gforth (compiled with @code{gcc-2.6.3} and @code{-DFORCE_REG}) with -Win32Forth and LMI's NT Forth, two systems written in assembly, and with -two systems written in C: PFE-0.9.11 (compiled with @code{gcc-2.6.3} -with the default configuration for Linux: @code{-O2 -fomit-frame-pointer --DUSE_REGS}) and ThisForth Beta (compiled with gcc-2.6.3 -O3 --fomit-frame-pointer). We benchmarked Gforth, PFE and ThisForth on a -486DX2/66 under Linux. Kenneth O'Heskin kindly provided the results for -Win32Forth and NT Forth on a 486DX2/66 with similar memory performance -under Windows NT. +Gforth (direct threaded, compiled with @code{gcc-2.6.3} and +@code{-DFORCE_REG}) with Win32Forth 1.2093, LMI's NT Forth (Beta, May +1994) and Eforth (with and without peephole (aka pinhole) optimization +of the threaded code); all these systems were written in assembly +language. We also compared Gforth with three systems written in C: +PFE-0.9.11 (compiled with @code{gcc-2.6.3} with the default +configuration for Linux: @code{-O2 -fomit-frame-pointer -DUSE_REGS}), +ThisForth Beta (compiled with gcc-2.6.3 -O3 -fomit-frame-pointer; +ThisForth employs peephole optimization of the threaded code) and TILE +(compiled with @code{make opt}). We benchmarked Gforth, PFE, ThisForth +and TILE on a 486DX2/66 under Linux. Kenneth O'Heskin kindly provided +the results for Win32Forth and NT Forth on a 486DX2/66 with similar +memory performance under Windows NT. Marcel Hendrix ported Eforth to +Linux, then extended it to run the benchmarks, added the peephole +optimizer, ran the benchmarks and reported the results. We used four small benchmarks: the ubiquitous Sieve; bubble-sorting and matrix multiplication come from the Stanford integer benchmarks and have been translated into Forth by Martin Fraeman; we used the versions -included in the TILE Forth package; and a recursive Fibonacci number -computation for benchmark calling performance. The following table shows -the time taken for the benchmarks scaled by the time taken by Gforth (in -other words, it shows the speedup factor that Gforth achieved over the -other systems). +included in the TILE Forth package, but with bigger data set sizes; and +a recursive Fibonacci number computation for benchmarking calling +performance. The following table shows the time taken for the benchmarks +scaled by the time taken by Gforth (in other words, it shows the speedup +factor that Gforth achieved over the other systems). @example -relative Win32- NT This- - time Gforth Forth Forth PFE Forth -sieve 1.00 1.30 1.07 1.67 2.98 -bubble 1.00 1.30 1.40 1.66 -matmul 1.00 1.40 1.29 2.24 -fib 1.00 1.44 1.26 1.82 2.82 +relative Win32- NT eforth This- + time Gforth Forth Forth eforth +opt PFE Forth TILE +sieve 1.00 1.39 1.14 1.39 0.85 1.78 3.18 8.58 +bubble 1.00 1.31 1.41 1.48 0.88 1.67 3.88 +matmul 1.00 1.47 1.35 1.46 1.16 2.36 4.09 +fib 1.00 1.52 1.34 1.22 1.13 1.93 2.99 4.30 @end example You may find the good performance of Gforth compared with the systems @@ -3136,12 +3695,18 @@ method for relocating the Forth image: l the actual addresses at run time, resulting in two address computations per NEXT (@pxref{System Architecture}). -The speedup of Gforth over PFE and ThisForth can be easily explained -with the self-imposed restriction to standard C (although the measured -implementation of PFE uses a GNU C extension: global register -variables), which makes efficient threading impossible. Moreover, -current C compilers have a hard time optimizing other aspects of the -ThisForth source. +Only Eforth with the peephole optimizer performs comparable to +Gforth. The speedups achieved with peephole optimization of threaded +code are quite remarkable. Adding a peephole optimizer to Gforth should +cause similar speedups. + +The speedup of Gforth over PFE, ThisForth and TILE can be easily +explained with the self-imposed restriction to standard C, which makes +efficient threading impossible (however, the measured implementation of +PFE uses a GNU C extension: @ref{Global Reg Vars, , Defining Global +Register Variables, gcc.info, GNU C Manual}). Moreover, current C +compilers have a hard time optimizing other aspects of the ThisForth +and the TILE source. Note that the performance of Gforth on 386 architecture processors varies widely with the version of @code{gcc} used. E.g., @code{gcc-2.5.8} @@ -3150,43 +3715,82 @@ machine registers by itself and would no register declarations, giving a 1.3 times slower engine (on a 486DX2/66 running the Sieve) than the one measured above. -@node Bugs, Pedigree, Internals, Top +In @cite{Translating Forth to Efficient C} by M. Anton Ertl and Martin +Maierhofer (presented at EuroForth '95), an indirect threaded version of +Gforth is compared with Win32Forth, NT Forth, PFE, and ThisForth; that +version of Gforth is 2\%@minus{}8\% slower on a 486 than the version +used here. The paper available at +@*@file{http://www.complang.tuwien.ac.at/papers/ertl&maierhofer95.ps.gz}; +it also contains numbers for some native code systems. You can find +numbers for Gforth on various machines in @file{Benchres}. + +@node Bugs, Origin, Internals, Top @chapter Bugs Known bugs are described in the file BUGS in the Gforth distribution. -If you find a bug, please send a bug report to !!. A bug report should +If you find a bug, please send a bug report to +@code{gforth-bugs@@mips.complang.tuwien.ac.at}. A bug report should describe the Gforth version used (it is announced at the start of an interactive Gforth session), the machine and operating system (on Unix systems you can use @code{uname -a} to produce this information), the -installation options (!! a way to find them out), and a complete list of -changes you (or your installer) have made to the Gforth sources (if -any); it should contain a program (or a sequence of keyboard commands) -that reproduces the bug and a description of what you think constitutes -the buggy behaviour. +installation options (send the @code{config.status} file), and a +complete list of changes you (or your installer) have made to the Gforth +sources (if any); it should contain a program (or a sequence of keyboard +commands) that reproduces the bug and a description of what you think +constitutes the buggy behaviour. For a thorough guide on reporting bugs read @ref{Bug Reporting, , How to Report Bugs, gcc.info, GNU C Manual}. -@node Pedigree, Word Index, Bugs, Top -@chapter Pedigree +@node Origin, Word Index, Bugs, Top +@chapter Authors and Ancestors of Gforth -Gforth descends from BigForth (1993) and fig-Forth. Gforth and PFE (by -Dirk Zoller) will cross-fertilize each other. Of course, a significant part of the design of Gforth was prescribed by ANS Forth. +@section Authors and Contributors + +The Gforth project was started in mid-1992 by Bernd Paysan and Anton +Ertl. The third major author was Jens Wilke. Lennart Benschop (who was +one of Gforth's first users, in mid-1993) and Stuart Ramsden inspired us +with their continuous feedback. Lennart Benshop contributed +@file{glosgen.fs}, while Stuart Ramsden has been working on automatic +support for calling C libraries. Helpful comments also came from Paul +Kleinrubatscher, Christian Pirker, Dirk Zoller and Marcel Hendrix. + +Gforth also owes a lot to the authors of the tools we used (GCC, CVS, +and autoconf, among others), and to the creators of the Internet: Gforth +was developed across the Internet, and its authors have not met +physically yet. -Bernd Paysan wrote BigForth, a child of VolksForth. +@section Pedigree + +Gforth descends from BigForth (1993) and fig-Forth. Gforth and PFE (by +Dirk Zoller) will cross-fertilize each other. Of course, a significant +part of the design of Gforth was prescribed by ANS Forth. -VolksForth descends from F83. !! Authors? When? +Bernd Paysan wrote BigForth, a descendent from TurboForth, an unreleased +32 bit native code version of VolksForth for the Atari ST, written +mostly by Dietrich Weineck. + +VolksForth descends from F83. It was written by Klaus Schleisiek, Bernd +Pennemann, Georg Rehfeld and Dietrich Weineck for the C64 (called +UltraForth there) in the mid-80s and ported to the Atari ST in 1986. -Laxen and Perry wrote F83 as a model implementation of the +Hennry Laxen and Mike Perry wrote F83 as a model implementation of the Forth-83 standard. !! Pedigree? When? A team led by Bill Ragsdale implemented fig-Forth on many processors in -1979. Dean Sanderson and Bill Ragsdale developed the original -implementation of fig-Forth based on microForth. +1979. Robert Selzer and Bill Ragsdale developed the original +implementation of fig-Forth for the 6502 based on microForth. -!! microForth pedigree +The principal architect of microForth was Dean Sanderson. microForth was +FORTH, Inc.'s first off-the-shelf product. It was developped in 1976 for +the 1802, and subsequently implemented on the 8080, the 6800 and the +Z80. + +All earlier Forth systems were custom-made, usually by Charles Moore, +who discovered (as he puts it) Forth during the late 60s. The first full +Forth existed in 1971. A part of the information in this section comes from @cite{The Evolution of Forth} by Elizabeth D. Rather, Donald R. Colburn and Charles @@ -3194,10 +3798,11 @@ H. Moore, presented at the HOPL-II confe Notices 28(3), 1993. You can find more historical and genealogical information about Forth there. -@node Word Index, Node Index, Pedigree, Top +@node Word Index, Node Index, Origin, Top @chapter Word Index -This index is as incomplete as the manual. +This index is as incomplete as the manual. Each word is listed with +stack effect and wordset. @printindex fn