CHANGES

-*- outline -*-

To understand the scope of these changes, please refer to the documentation.

* New in version 1.3

** Various

  + Use gforth 0.7.3 instead of gforth 0.6.x.

  + Use GPL v3 to follow gforth move.

* New in version 1.2.5

** New features

  + Make stack size configurable in multitasker. Feature requested
    by David McNab <david@rebirthing.co.nz>.

** New optimization

  + Use "subwf" when it leads to better code. Feature requested by
    David McNab <david@rebirthing.co.nz>.

** Bug fixes

  + Fix overflow in "goto" instruction patching in "multitasker.fs". Bug
    reported and diagnosed by Alex Holden <alex@linuxhacker.org>.

  + Fix a bug involving dead code elimination and conditional branches.
    Reported by Alex Holden <alex@linuxhacker.org>.

  + Fix a bug involving "exit" followed by "if". Reported by
    Alex Holden <alex@linuxhacker.org>.

  + Fix a bug involving constant strings. Reported by Alex Holden
    <alex@linuxhacker.org>.

* New in version 1.2.4

** New words

  + Add the "flag" word from David McNab <david@rebirthing.co.nz> which
    handles 1-bit variables.

** New library

  + Add libroll.fs from David McNab <david@rebirthing.co.nz>, which adds
    the "roll" and "-roll" words.

** New optimization

  + When the return value is stored in W, use "retlw" to return. Implemented
    after a question from David McNab <david@rebirthing.co.nz>.

** Code and documentation enhancements

  + Import "return-in-w" into target vocabulary and document it. Suggested
    by David McNab <david@rebirthing.co.nz>.

  + Document the effect of "exit" in inlined words. Thanks to
    Alex Holden <alex@linuxhacker.org> for asking for clarification.

** Bug fixes

  + Flash tables generated an error due to new nesting checks introduced in
    PicForth 1.2.2. Reported by Jamie Lawson <jlawson@ces.uoguelph.ca>.

  + Fix bug in macro processing where a word defined first in the
    metacompiler then later in target mode (such as "suspend-interrupts"
    when "picisr.fs" is included) was seen as the first definition in
    macros. Reported by Alex Holden <alex@linuxhacker.org>. 

  + Fix bug in multitasker when multiple code banks were involved.
    Reported by Alex Holden <alex@linuxhacker.org>.

  + Fix bug in "resolve" when multiple code banks are involved.
    Reported by Alex Holden <alex@linuxhacker.org>.

* New in version 1.2.3

** Bug fix

  + The "0 <" phrase (not "0<") could lead to incorrect result when
    not followed by a conditional construct. Reported by
    Alex Holden <alex@linuxhacker.org>.

  + Implement the "abs" word as documented in the manual.

  + The "dup 0<>" phrase was incorrect due to mowf not setting the "Z"
    status bit. Reported by Alex Holden <alex@linuxhacker.org>.

* New in version 1.2.2

** New words

  + "case"/"of"/"endof"/"endcase". Suggested by David McNab
    <david@rebirthing.co.nz>.

  + "write-map"/"write-dis". Implemented by
    Alex Holden <alex@linuxhacker.org>.

** Enhancements

  + Check nesting of loops and conditional constructs as well as
    non-nesting of definition words. Suggested by David McNab
    <david@rebirthing.co.nz>.

  + Do not warn about words redefined in PicForth. Suggested by
    Alex Holden <alex@linuxhacker.org>.

  + Output from "map" and "words" is now in low->high order not high->low.
    Implemented by Alex Holden <alex@linuxhacker.org>.

** Bug fixes

  + Allow empty (but useless) code words
  + Fixed a slight stack leak in "words" and "map". Fix by
    Alex Holden <alex@linuxhacker.org>.
  + Fixed a typo in "unsupported". Fix by Alex Holden <alex@linuxhacker.org>

* New in version 1.2.1

** Bug fixes

  + Fix a problem with "adjust-bank". Reported by David McNab
    <david@rebirthing.co.nz>.

* New in version 1.2

** Optimizations

  + "nip" now optimizes code such as "1 2 nip" by replacing it by "2".
    This situation can arise when a bit name is given and only the
    bit number is interesting.

** Enhancements

  + "picisr.fs" now include versions of "suspend-interrupts" and
    "restore-interrupts" that can be nested up to 256 levels. However
    this requires one more byte of memory (problem signaled by
    Alex Holden <alex@linuxhacker.org>).

  + PicForth will issue warnings (which by default are fatal) when a
    bank mismatch has been detected.

** Cleanups

  + Remove extra definition of "set-wrt". Reported by Jamie Lawson
    <jlawson@ces.uoguelph.ca>.

** Bug fixes

  + Interrupts were not properly suspended during an EEPROM write. This
    has been found by the new bank mismatch detection code.

* New in version 1.1

** New words  

  + Import conditional compilation words "[IF]", "[ELSE]", "[THEN]",
    "[IFDEF]" and "[IFUNDEF]" from gforth. Suggested by David McNab
    <david@rebirthing.co.nz>.
  + "disallow-optimizations" and "allow-optimizations" allow a finer
    control on PicForth optimizations.

** Bug fixes

  + Test with empty action part and a "else" is now handled properly.
    Bug reported by Alex Holden <alex@linuxhacker.org>.
  + Make "include" and "needs" work properly.

** Miscellenaous

  + Add more comments to explain PicForth internals
  + Add a note in the documentation about static flash strings working
    in target mode only.Problem reported by Alex Holden <alex@linuxhacker.org>.

* New in version 1.0.1

** Distribution glitches in 1.0

  (reported by David McNab <david@rebirthing.co.nz>)
  + Missing tools/bootloading directory
  + Missing dcc2.fs

** New files

  + Regression tests

** Changes

  + gforth's call is now hidden by picassembler's call

* New in version 1.0

** Port to GForth 0.6.2

  + PicForth now works with GForth 0.6.x line

* Changes since PicForth 0.32

** Enhancements

  + Include new loader from David McNab <david@rebirthing.co.nz> in
    tools/bootloading.

* Changes since PicForth 0.31

** Enhancements

  + Added jump tables, thanks to David McNab <david@rebirthing.co.nz>.
  + The "::code" word was added, thanks to
    David McNab <david@rebirthing.co.nz>.
  + Added the SSPCON2 bit definitions, thanks to
    J.C. Wren <jcwren@jcwren.com>.
  + The "pick" word was added, thanks to J.C. Wren <jcwren@jcwren.com>.
  + The "rot", "-rot" and "2swap" were added in libextra.fs,
    thanks to J.C. Wren <jcwren@jcwren.com>.

** Bug fixes

  + 2dup fix by David McNab <david@rebirthing.co.nz>. Also noticed by
    J.C. Wren <jcwren@jcwren.com>.
  + PCLATH could be wrong in a loop located in upper banks. Bug found and
    fixed by David McNab <david@rebirthing.co.nz>.
  + Work around problem with GForth 0.5.0 kernel/require.fs file by including
    a slightly modified version info PicForth. Bug reported by
    David McNab <david@rebirthing.co.nz>.

** Doc fixes

  + Document trisa/trisb/trisc. Omission noted by David McNab
    <david@rebirthing.co.nz>.

** Tools

  + Add tools/fdasm from David McNab <david@rebirthing.co.nz>.
  + Add tools/bootloading from David McNab <david@rebirthing.co.nz>.

* Changes since PicForth 0.30

** Glitch fixes

  + Make the release ready for PIC16F88.

* Changes since PicForth 0.29

** Port for PIC16F88 architecture

  + PicForth can now generate code for PIC16F88 architecture, thanks to
    Jamie Lawson <jlawson@ces.uoguelph.ca>.

** License clarification

  + The various libraries have been explicitely marked as being in the
    public domain. Thanks to William Kitchen <vilvoy@pixeltile.com> for
    reporting this.

* Changes since PicForth 0.28

** Bug fix

  + Dumb code such as "7 9 < if ... then" (which would never occur in real
    programs) is now properly handled. The optimizer was too enthusiastic
    and did not set the carry flag properly.

* Changes since PicForth 0.27

** New words

  + The "sleep" word is imported from assembler and can be used from Forth
    code.

** Bug fixes

  + Various bug fixes related to high addresses.

* Changes since PicForth 0.26

** New library

  + Library "libstrings.fs" allows the creation of 7 bits packed strings
    in flash memory. Each program word holds two characters and strings
    are zero terminated. An iterator allows the retrieval of one character
    at a time.

** Incompatible change

  + Line-oriented literal strings now use CR/LF (two characters) instead of
    CR alone. This makes more terminal software happy.

* Changes since PicForth 0.25

** New words

  + "w-!" removes the content of W from a memory register.

** New optimizations

  + "-!" can handle more cases.

* Changes since PicForth 0.24

** New words
  + "suspend-interrupts" and "restore-interrupts" allow interrupt bit saving
  and restoring. Builtin words do use those internally. If "picisr.fs" is
  not included, those words are noops.

* Changes since PicForth 0.23

** New words

  + "rrf!" and "rlf!" allow for variable bit shifting without resorting to
  assembler.

  + "t," allows for a single byte to be added in a table.

** New optimizations

  + "lshift" and "rshift" have been further optimized.
  + "goto" is used in place of "call" in more places when it is possible.

* Changes since PicForth 0.22

** Feature change

  + "v-next" rememebers the variable used at "v-for" time. Therefore, "v-next"
  no longer takes a variable address as parameter.

** New words

  + "table", "ftable", "eetable", "table>" and "end-table" allow to create
    respectively RAM, flash or EEPROM tables.

  + The library "picflash.fs" contains new words "fcreate", "f,", "fallot"
    and "fhigh!".

** New documentation

  + Some documentation has been started. Look for "picforth.pdf",
  "picforth.txt", "picforth.info" and "picforth.html" and use the one
  which most suits your needs and tastes.

* Changes since PicForth 0.21

** New features

  + It is now possible to use the whole PIC code space.

** Removed words

  + The words "table" and "tc:" have been removed as they were inefficient
  and useless in their current form.

* Changes since PicForth 0.20

** New words

  + The words "bank0", "bank1", "bank2" and "bank3" allow to choose the
  memory bank in which next variables will be stored.

  + "needs" works the usual way.

  + "set-stack-size" allows to set the default stack size.

* Changes since PicForth 0.19

** New optimizations

  + Obvious "cmove" cases are optimized.

** Doc emphasis

  + Make it clearer that there is an assembler included.

* Changes since PicForth 0.18

** Bug fix

  + Some rare conditions could lead to bad code being generated, because
    of missing optimization barriers (the only legit sequence with
    problems was "bit-clr? until").

* Changes since PicForth 0.17

** Data area initialization

  + Data area is now initialized if "," is used. Note however that variables
    are not automatically initialized to 0 (see "README").

* Changes since PicForth 0.16

** New optimizations

  + Expressions followed by a test (such as a "if") will not be normalized
    if it is not needed.

** New words

  + Two new words, "bit-clr?" and "low?" have been added.

** New libraries

  + The library "libcmove.fs" implements ANS Forth "CMOVE".

** New example

  + A new real-life example "spifcard.fs" has been added.

** Removed words

  + The word "/if", "c-if", "c-/if", "/until", "/while" and "=if" have been
    removed as the new optimizations makes them unnecessary.

* Changes since PicForth 0.15

** New optimizations

  + More useless loads have been removed, generating even better code.

  + Words "hex>nibble" and "nibble>hex" from "libnibble.fs" have been
    optimized.

  + "swap" and "drop" after a string literal word are optimized.

** New words

  + "=if" adds a new test.

** Preparation for larger programs

  + Jump to main program and interrupt handler properly handle PCLATH.

** New example

  + "i2cloader.fs" is a flash and eeprom programmer using I2C.

* Changes since PicForth 0.14

** New words

  + "bit" builds a name representing a particular bit at a particular address.

** Behaviour changes

  + Named bits (such as "c", "z", "t0if", ...) do now push their address
    as well, and must be used without any address. For example, to test
    for timer 0 overflow, you must use "t0if bit-set? if ... then".

** Parameters order changes

  + Words "bit-set", "bit-clr", "bit-set?", "bit-toggle", "high", "low",
   "high?" and "toggle" now use inverted parameters (push port first then
    bit number). Symbols defined with "bit", "pin-a", "pin-b", "pin-c",
    "pin-d" or "pin-e" can now be used in assembly code as the parameter
    order is similar to the Forth one.

** Renamed words

  + String + carriage return manipulation word has been renamed.

** Renamed example

  + "checker.fs" has been renamed "controller.fs", as the previous name
    was misleading.

* Changes since PicForth 0.13

** New words

  + "/and" "invert" the top-of-stack then "and" the two top values.
  + "swapf-tos" exchanges nibble of top-of-stack.
  + Two words (see README) allow you to store strings in the EEPROM.

** New optimizations

  + "lshift" with a bit count greater than 3 will use a shorter code than
    before.

  + "and" and "/and" will use bit manipulation when this is more efficient.

** New example

  + A new complete example "checker.fs" is included.

** New library

  + The "libnibble.fs" library converts characters to nibbles and nibbles
    to characters.

** Bug fixes

  + In one case, the code generated by a "-" followed by "if" could be
    incorrect.

  + In some cases, "lshift" and "rshift" could generate incorrect code.

* Changes since PicForth 0.12

** Bug fixes

  + The basic multitasker has been fixed to work correctly when the "yield"
    operation crosses a 256 bytes page limit.

* Changes since PicForth 0.11

** New multitasker

  + A new multitasker (cooperative, priority-less, much simpler) has been
    added. See README file for information on how to use both multitaskers.

** New optimizations

  + "incfsz" and "decfsz" will be used when it is possible.

* Changes since PicForth 0.10

** New features

  + Tasks of equal priority will all run if one of them runs (and code is
    more efficient).

** New optimizations

  + Regular tasks need only 1 bit of data each instead of 1 byte (bits are
    aggregated, 8 tasks will need only 1 byte of RAM).

  + Some redundant loads before tests have been suppressed.

* Changes since PicForth 0.9

** New features

  + PicForth now includes a priority-based cooperative multitasker, see
    README file for details.

** New words

  + "lshift", "rshift", "2*" and "2/" are implemented.

* Changes since PicForth 0.8

** New words

  + "invert!" inverts the content of an address.
  + "-!" is implemented.

** New modes

  + "macro" allows you to enter the macro definition mode, while "target"
    gets you back to code generation.

** New optimizations

  + "drop" followed by an integer leads to very efficient code.
  + "+" and "-" have been further optimized.

* Changes since PicForth 0.7

** New parameter passing convention

  + A new defining word "::" allow efficient W register parameter passing.
    ">w" and "w>" respectively pop the top-of-stack into w and push w on
    the stack. They can be used to implement efficient return value handling.

** New optimizations

  + "or" now uses bit-set instructions when it makes sense, as well as "or!",
    "and!" and "/and!".

  + "negate" and "invert" have been optimized.

** New words

  + "recurse" is implemented the traditional way.

  + ">input" and ">output" change a pin direction by working on the
    corresponding tris register.

* Changes since PicForth 0.6

** New optimizations

  + A load followed by a constant + or - will be even further optimized.

** New check

  + The compiler now checks that you do not run out of code space and out of
    RAM space (see README for more explanations).

** Bug fixes

  + The Makefile was not ideal and could induce some bugs due to the
    redefinition of "include".

  + The previous definition of "over" was not interrupt-safe.

  + Some opcodes were not properly displayed by the disassembler.

* Changes since PicForth 0.5

** New disassembler and interactive mode

   + If you use "make interactive", you will be dropped into an interactive
     mode where you can disassemble words using "see", "words", "map" and
     "dis".

* Changes since PicForth 0.4

** New optimization

   + If an operation targets the top of stack and this one is then
     popped into w, the operation is modified to target w directly.

** New example

   + A new example, "silver.fs", contains some code that runs on a
     smartcard.

** New words

   + "eecreate" and "ee," manipulate EEPROM content

** New features

   + The EEPROM content can be programmed and is now dumped (see smartcard
     example).

** Bug fixes

   + "ee@" selected the flash instead of the EEPROM

* Changes since PicForth 0.3

** New words

  + "high", "low", "high?" and "toggle" are aliases for "bit-set",
    "bit-low", "bit-set?" and "bit-toggle" intended to work on ports

* Changes since PicForth 0.2

** New library files

Add library files "libfetch.fs" and "libstore.fs" which were forgotten in
previous versions and are used by "generator.fs".

* Changes since PicForth 0.1

** New words

  + "until" and "/until" (control structures)
  + "clrwdt" (accessible from Forth)
  + "pin-a", "pin-b", "pin-c", "pin-d", "pin-e" (pin mapping)

** Renamed words

  + "bit-clear" is renamed to "bit-clr"