= Standard ML of New Jersey Change Log
The Fellowship of SML/NJ
:revnumber: {version}
:revdate: {release-date}
:stem: latexmath
:source-highlighter: pygments
:tabsize: 8
:note-caption: UPDATE
:issue-base: https://github.com/smlnj/smlnj/issues
:pull-base: https://github.com/smlnj/smlnj/pull
:legacy-issue-base: https://github.com/smlnj/legacy/issues
:legacy-pull-base: https://github.com/smlnj/legacy/pull

This file documents changes to the *Standard ML of New Jersey* system
since January of 2014 (Versions after 110.78).  Earlier changes are
documented in the `HISTORY-pre2015` file. The change log primarily
covers the compiler, the compilation manager (*CM*), the *MLRISC*
library, and the runtime system.  There are occasional entries about
other components (_e.g._, the *SML/NJ Library* and *ML-LPT*), but
these components have their own change logs that should be consulted.

//////////////////////////////////////////////////////////////////////
This change log is in ASCII doc format.  An HTML version of the
change log can be generated using the command

	make html

An entry should be made for _every_ commit to the repository.
The entries in this file will be used when creating the README
for new versions, so keep that in mind when writing the
description.

Also note that we now use Asciidoctor (asciidoctor.org) to process the
file, since the original Asciidoc is no longer under active development
and asciidoctor is also faster.
The structure of the HISTORY is that there is a section for
each release, which starts with a section header of the form

== Version xxx.yy; yyyy/mm/dd

The content of a section is a list of entries.  The form of an
entry should be:

    [yyy/mm/dd]::
    +
    Description ...
    +
    owner:URL[Your Name]

Note that we put "+" at the beginning of blank lines.  Entries are items
in a labeled list and the "+" character keeps eveything in the same list
element.

Here is a quick asciidoc cheat sheet:

    +					new paragraph
    *foo*				bold "foo"
    _foo_				italic "foo"
    `foo`				teletype "foo"
    http:/some.website.org/path[]	URL
    bugref:123[]			displays as "#123" with
					a link to the bug report.
    bugref:123[feature]			displays as "#123" with a
					link to the feature request.
    owner:url[name]			displays name with URL link.

Sub lists should be bracketed with lines containing just "--".
Bulleted list items start with a single dash or one to five
asterisks followed by some white space then some text. Numbered
list items begin one to five period characters, followed by
some white space then the item text.

Literal (verbatim) blocks are delimited by
.....................
   stuff
.....................

Superscripts and subscripts are denoted by putting ^ (or ~)
around the text to superscripted (superscripted).  For example,
the number 256 can be written as 2^8^.

SML source code displays can be included as source blocks:

[source,sml]
------------
structure Foo = struct val x = 1 end
------------

To process the file, you will need asciidoctor and the pygments.rb gem
installed.  See the Asciidoctor manual at https://asciidoctor.org/docs/user-manual
for more information.

We have hijacked the "NOTE" admonition to mark updates to previous entries.
Use the following syntax for such updates:

[NOTE]
.2022/07/01
====
Here is an update to the entry
====

//////////////////////////////////////////////////////////////////////

//====================================================================
//== Recent updates

//====================================================================
== Version 2026.1; 2026/03/14

//--------------------------------------------------------------------
[2026-03-10]::
Fix for Issue #338[incorrect compilation of some large integer literals].
This bug was in the **LLVM** submodule.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2026-02-26]::
Modified **CM** so that the "required privileges" message is no longer
printed when the CM verbose flag is set to `false` (_e.g._, by using
the command-line option `-Ccm.verbose=false`)
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/12/23]::
Added `Unsafe.Int` structure to provide typed access to integer addition
and subtraction without overflow checking.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/12/23]::
Switch to using `Real.fmt StringCvt.EXACT` when printing real values
in the REPL.  This change addresses Issue #335 (REPL should always
print reals as valid SML real literals).  Note, we might want to
eventually implement something more specialized, since values like
`1.2` are rendered using scientific notation (_i.e._, `0.12E1`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 2025.3; 2025/12/22

//--------------------------------------------------------------------
[2025/12/13]::
Bind the bit-counting and rotation primops that were added in 2025.2
in the `Inline` structure.  This change will allow them to be used in
the Basis Library in 2026.1.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/12/10]::
Reorganized some of the **CM** internal library structure.  The file
`system/smlnj/internal/cm-sig-lib.cm` has been deleted.  It just defined
the `CM` and `CMB` signatures.  These definitions have been moved into
the libraries where the corresponding structures are defined.  The `CM`
signature is now defined in `system/smlnj/cm` and the `CMB` signature
is defined in `cm/bootstrap`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/12/09]::
Changed some names in *CM* to avoid confusion with modules of
the same name in the compiler.  Specifically, the following
were changed:
+
--
* the signature `COMPILE` was changed to `TRAVERSE`
* the functor `CompileFn` was changed to `CompilerTraverseFn`
* the file `cm/compile/compile.sml` was renamed as `cm/compile/traverse.sml`
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/12/07]::
Added support for normalizing the CFG before export (normalization
means alpha-renaming the lambda variables to canonical names).
There is a new control (-Ccg.normalize-cfg or `CG.normalizeCFG`) for
enabling this feature.  It affects code generation, dumping of CFG
pickles, and printing of the CFG.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/08/19]::
Remove `preserveLvarNames` control from `Control` structure, since it
is not used and can be confused with `Control.ElabData.saveLvarNames`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/08/19]::
Changed the base pointer of a pair arena to be page-aligned,
consistent with the base pointers of all other arenas.
Previously, the convention is to make the base pointer offset by two
words because `polyEqual` expects a header word before all objects.
But when the size of the pair arena is exactly the size of a page,
`MarkRegion` erroneously ignores the first two words of the last page.
+
See {pull-base}/322[Pull Request #322 (Fix heap export inconsistency
caused by pair arena offsets)] for details.
+
owner:cs.uchicago.edu/~byronzhong[Byron Zhong]

//--------------------------------------------------------------------
[2025/08/11]::
Reworked type unification. When unifying two types, sometimes the
types cannot be unified directly, but their head-reduced forms can.
Because eagerly head-reducing all types can lead to an explosion of
terms, the legacy branch head-reduces either types when a unification
error occurs and retries unification. This leads to an exponential
blowup when type-checking functions with a large number of curried
arguments. The development branch handles the lazy head-reduction more
directly, but the previous implementation ignores a few cases where
the direction of tyvar unifications matters. For example, a UBOUND
tyvar cannot be instantiated as an OPEN tyvar, but the opposite
direction works; OVLD tyvars have metadata that needs to be maintained
for overload resolution to work. This change patches the missing
cases.
+
In addition, the NOpat pattern, signaling an elaboration error on a
pattern, is handled in the typechecker.
+
This change fixes {issue-base}/137[Issue #137 (Typechecker hangs with
a large number of curried arguments)], {issue-base}/262[Issue #262
(Compiler bug in type checker: unexpected pattern)], and
{issue-base}/317[Issue #317 (Bug in type checking/inference with type
abbreviations through transparent functor application)].
+
owner:cs.uchicago.edu/~byronzhong[Byron Zhong]

//--------------------------------------------------------------------
[2025/08/10]::
Replaced the pickler for skeleton files in **CM** with one that is
generated from an **ASDL** specification.  This change is a first step
in replacing the pickler-combinators with **ASDL** picklers.  See
`cm/smlfile/skel-io.sml` and `cm/smlfile/asdl/skeleton.asdl` for more
details.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/08/05]::
Changed the way external references are passed during translation to
PLambda. Previously, the external references are grouped by the PIDs
of their compilation units, and the units are sorted by the PIDs. As a
result, the input order is a property of the external module. This
change sorts the units by the order of their appearances in the source
code; modules that are referenced earlier are put before those
referenced later. This makes the input order a property of the code
itself.
+
This change fixes {issue-base}/319[Issue #319 (Nondeterministic import
order)].
+
owner:cs.uchicago.edu/~byronzhong[Byron Zhong]

//====================================================================
== Version 2025.2; 2025/07/29

//--------------------------------------------------------------------
[2025/07/19]::
Changed the **CPS** IR to track the argument types of continuations.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/07/19]::
Changed the way that GC invocation code is generated to not distinguish
between different types that have uniform representation (*i.e.*, `LABt`,
`PTRt` and `TAGt`). This change results in significant shrinkage in the
size of heap images (*e.g.*, 78Kb for the compiler) and more closely
matches the behavior of the old **MLRISC** code generator.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/07/16]::
Ported various bug fixes for real/string conversions from the legacy
repository.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/07/16]::
A number of changes to the CFG IR mostly affecting the *pure* primops:
+
--
* replaced the `UMUL` and `SMUL` operators with `MUL`, since the are
  all the same
* renamed the shift operators to `SHL`, `ASHR`, and `LSHR`
* added bit-counting operators: `CNTPOP`, `CNTLZ`, and `CNTTZ`
* added bit-rotation operators: `ROTL` and `ROTR`
* added `BITS_TO_FLOAT` and `FLOAT_TO_BITS` primops
* added `FREM` and `FMADD` primops
* removed the `OFFSET` expression form, since it is never generated.
--
+
These changes affect both the **SML** and {cpp} sides of the code
generator.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/07/09]::
Added `charSize` and `realSize` functions to the `Unsafe` module.  These
are placeholders for eventual primops that can be used for compile-time
tests for the sizes of the default `char` and `real` types (similar
to the `wordSize` primop).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/06/23]::
Add build targets for a standalone runtime system library, `runx.<arch>-<os>`,
for `arm64-darwin`, `amd64-darwin`, and `amd64-linux` to support `heap2exec`.
+
owner:cs.uchicago.edu/~byronzhong[Byron Zhong]

//--------------------------------------------------------------------
[2025/04/11]::
Add a pass to eliminate redundant computation in the CPS IR.  This
pass does value numbering for most pure and arithmetic expressions
and also eliminates redundant conditional control flow.  It needs
more tuning, however, so it is currently disabled by default.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/04/11]::
Port fix for {legacy-issue-base}/347[Legacy Issue #347 (`Unsafe.cast`
causes Compiler bug)].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/03/26]::
Removed deprecated fuctions from `SMLofNJ.SysInfo` module and changed
the `WIN32` constructor to `WINDOWS`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/03/25]::
Fixed the **macOS** installation for **arm64** processors; these changes
fix {issue-base}/297[Issue #297 (macOS installer does not initialize
CM paths correctly)].  Also made the **macOS** install target consistent
across the various places where it is specified.  It is now set to
Version 11 (Big Sur).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/02/26]::
Reworked the mechanism for grouping the first-order CPS functions into
clusters.  The new implementation will remove unreachable known functions.
Furthermore, the normalization pass will not signal an error if a cluster
that has no entry is encountered (should be impossible with the other
change).  Previously, normalization would get into an infinite loop
in such situations.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/02/20]::
Add a mechanism for dumping out the cluster graph as a ".dot" file
before and after normalization of the clusters.  Have also restructured
the handling of clusters to make normalization mandatory, since that
is a requirement of the LLVM backend.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/02/19]::
Fixed a bug in the **arm64** assembly code for `Assembly.A.scalb` (bad
allocation of the result).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 2025.1; 2025/02/14

//--------------------------------------------------------------------
[2025/02/12]::
Reimplementation of the `heap2exec` script to use the `heap2obj` program
(instead of `heap2asm`).  The `heap2obj` program is part of the *LLVM*
infrastructure and takes advantage of the fact the *LLVM* knows how to
create object files for the host system.  Thus `heap2obj` is more portable
than `heap2asm` and faster (since it does not have to produce a textual
assembly file).
+
In addition, I have added support to the `ml-build` script to produce an
executable from the heap-image file that it normally generates.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/02/10]::
A minor change to the heap-image layout (the new version number is
`0x02102025`) and other improvements to heap import/export.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/02/08]::
Changed the representation of big-object regions in the heap to avoid
issues with write protection for executable code on **macOS**/**arm64**.
The old design put the region header into the first page of the region,
which is write protected on **arm64**.  The new design allocates the
region header in the *C* heap and puts a pointer to it into the first
page of the region.  We only need to read that pointer during GC, so
this avoids the write-protect issues.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/02/07]::
Reworked the implementation of code objects in both the compiler and
runtime system.  The new design should make is easier to deal with
the problems related to write protection for executable code on
**macOS**/**arm64**.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/01/31]::
Fix for {issue-base}/295[Issue #295 (Incorrect constant folding of
word equality)].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2025/01/21]::
Fix for {issue-base}/294[Issue #294 (compiler bug aborts build of
istari)].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/10/25]::
Ported fix for {legacy-issue-base}/328[Legacy Issue #328 (`Real.fromString`
broken in 110.99.5 and 110.99.6)].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/10/25]::
Ported fix for {legacy-issue-base}/305[Legacy Issue #305 (`Date.date`
incorrectly modifies local time with timezone offset)].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/10/11]::
Changed the startup behavior so that if the `@SMLquiet` command-line
option is specified, then the banner is not printed.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/10/11]::
Taking advantage of the previous change by moving the fusion of
integer/word conversions to the `ContractPrim` structure.  This
change means that conversions do not have to be adjacent in the
CPS IR to be composed.  Also added some missing identities for
the conversions.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/10/11]::
+
Improved the tracing of variable bindings in contraction by adding
the `ARITHinfo` and `PUREinfo` constructors (the `WRPinfo` constructor
is rendered obsolete).  This change was motivated by the desire to
eliminate a redundant range test from the code
+
[source,sml]
------------
fun byte2char w = chr (Word8.toInt w)
------------
+
It also allows for `WRAP(UNWRAP ...)` fusion.  In the future, we can
also use this mechanism to move the numeric-conversion fusion operations
to the `ContractPrim` structure, which will allow us to fuse compositions
that are not adjacent in the IR.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/08/05]::
+
Renamed the *LLVM* submodule directory to include a version number
(_e.g._, `llvm10` or `llvm18`).  The `build.sh` script has been modified
to allow the path to the *LLVM* subdirectory to be overridden.  These
changes will allow new versions of the *LLVM* submodule to be tested
in parallel with the existing version and make it easier to switch
versions.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 2024.2; 2024/07/07

//--------------------------------------------------------------------
[2024/06/15]::
+
Restructured the repository so that the **LLVM** library is now
a submodule (_e.g._, `git@github.com:smlnj/smlnj-llvm-10.git`).
The `llvm` source tree has also moved from the top level to the
runtime system.  Furthermore, the CFG code generator is now a
static library that is built in the *LLVM* submodule.  Likewise,
the **cfgc** tool is now located in the *LLVM* submodule.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 2024.1; 2024/05/17

//--------------------------------------------------------------------
[2024/03/06]::
+
Changed `Unsafe.Real64.toBits` to `Unsafe.Real64.castToWord` and
`Unsafe.Real64.fromBits` to `Unsafe.Real64.castFromWord`.  These new
names match MLton's names for these operations.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/03/05]::
+
Reimplement the `PackReal64Big` and `PackReal64Big` structures to use
the bit-casts between 64-bit reals and 64-bit words.  This change
fixes {issue-base}/300[Issue #300 (``PackReal64``{``Big``,``Little``}``.update``
is not implemented)].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/02/05]::
+
Added `host_word_size` and `host_big_endian` primops.  These will expand
into constant functions (e.g., `fn () => 64` for `host_word_size` on a
64-bit system) that will be visible to the optimizer.  We can then use
code like:
+
[[source,sml]
------------
if InlineT.host_big_endian() then ... else ...
------------
+
where the `if` can be evaluated at compile time.  These primops are also
available to user code via the `Unsafe` structure.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/03/13]::
+
Ported various fixes and improvements from the legacy version.  These
include
+
--
* Fix for {legacy-issue-base}/194[Legacy Issue #194 (Incorrect
  formatting of real number)]
* Fix for {legacy-issue-base}/269[Legacy Issue #269 (`Real.realMod` and
  `Real.split` produce incorrect result for values close to zero)]
* Fix for {legacy-issue-base}/283[Legacy Issue #283 (`TextIO.inputAll`
  segfaults when reading 980M file)].
* Fix for {legacy-issue-base}/300[Legacy Issue #300 (
  ``PackReal64``{``Big``,``Little``}``.update`` is not implemented)].
* Added implementation of `Real64.nextAfter`.
* Rewrite of the mechanisms used to implement conversions
  between strings and reals.
* Added `Unsafe.Real64` structure
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/03/03]::
+
Expose the machine property functions as `Unsafe.isBigEndian` and
`Unsafe.wordSize`.  These functions are inlined by the compiler, which
allows one to expect tests of the form `if Unsafe.isBigEndian()` to
be evaluated at compile time.  These primops are also available to
user code via the `Unsafe` structure.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/03/01]::
+
Improved the `Unsafe.Real64.fromBits` implementation to use a cast
and a reference (instead of pack/unpack from a byte array).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2024/02/25]::
+
Fixed {issue-base}/284[Issue #284 (Incorrect printing of source code
in error message)].
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2024/02/05]::
+
The implementations of `PackWord64Little.update` and `PackWord64Big.update`
were swapped on 64-bit platforms (resulting in byte-order reversal).  These
have been fixed.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 2023.1; 2023/12/10

//--------------------------------------------------------------------
[2023/12/06]::
+
For various reasons, the LLVM backend has to resolve relocation symbols
as part of the process of generating the final object code to the heap.
While LLVM provides a generic API for working with object files, patching
relocation information is necessarily dependent on both the architecture
and object-file format.  For the
https://en.wikipedia.org/wiki/Executable_and_Linkable_Format[**ELF**]
format, there were several complications that the original implementation
did not handle (_e.g._, relocation information is stored in a separate
section from the section that it is applied to).  The handling of
object-files, sections, and relocation records has been rewritten to
handle the **ELF** file format.  These changes fix issues #233
({issue-base}/233[Installation of SML/NJ 2021.1 fails on Ubuntu 20.04])
and #272 ({issue-base}/272[Unable to build LLVM when running `build.sh`]).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2023/11/21]::
+
Fix bug in `new-literals.sml`, where the integer value 2^31^ was being
stored as a 32-bit signed integer in the literal table, instead of as
a 64-bit signed integer.  This change fixes {legacy-issue-base}/287[Legacy
Issue #287 (The word literal `0wx80000000` is incorrectly converted to
`0wx7FFFFFFF80000000`)].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2023/10/13]::
+
Add contraction rule for when two calls to `SETHDLR` appear in
sequence.  This situation arises when the body of a handler is
optimized away.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2023/06/14]::
+
Port fix for legacy bug
https://github.com/smlnj/legacy/issues/278[#278 (`CharBuffer.addSlice`
does not properly handle starting offsets)].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/12/19]::
+
Port fixes for Slice `all` combinators from legacy branch (see
https://github.com/smlnj/legacy/pull/264[pull request 264]).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/12/13]::
+
Fixing some issues with building a macOS package.  The
`postinstall`/`postupgrade` scripts needed to be updated to use
the `build.sh` script and the `build.sh` script needed a fix so
that it can build the documentation even when there
is not an installation of *SML/NJ* present.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 2022.1; 2022/08/25

//--------------------------------------------------------------------
[2022/08/25]::
+
Added `system/iter-make` script to iterate the compilation of the
compiler.  This script replaces the old `fixpt` script and is necessary
when changing the version number of the system.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/08/15]::
+
The change log file (`HISTORY.txt`) has been split into two files;
one covering the period before 2015 and one covering changes since
then.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/08/15]::
+
The source repository has been migrated to
https://github.com/smlnj/smlnj[**GitHub**].  With this migration, we
have substantially reorganized the source tree and build scripts.
+
The `base` directory has been eliminated; most of its components
(`cm`, `compiler`, `runtime` and `system`) have been lifted to
the top-level of the source tree.  The other top-level directories
are `doc`, `libraries`, `llvm`, `smlnj-lib`, and `tools`.
The `libraries` and `tools` directories hold most of the non-core
components of the system, such as `cml`, `ml-yacc`, __etc__.
+
The `config/install.sh` script has been replaced by the `build.sh`
script.  The build process is simplified because the only component
that is not in the **git** repository is the boot files.  We have
also removed the deprecated support for 32-bit systems from the
various build scripts.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/07/27]::
+
Fix for {issue-base}/235[MSI installer for SMLNJ 110.99.2 reports as
version 0.0.0.0].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/07/25]::
+
Implemented Basis Library proposal
https://github.com/SMLFamily/BasisLibrary/wiki/2021-001-Add-getWindowSz-function-to-Posix.TTY-structure[2021-001]
(Add getWindowSz function to Posix.TTY structure).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/07/25]::
+
Implemented Basis Library proposal
https://github.com/SMLFamily/BasisLibrary/wiki/2022-001-Add-value-tau-to-MATH-signature[2022-001]
(Add `tau` to `MATH` signature).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/07/24]::
+
Fix for {issue-base}/234[ml-build fails on Windows with error].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/07/24]::
+
Fix for {issue-base}/51[makeml and installml scripts do not like
locations with spaces].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/07/22]::
+
Fix for {issue-base}/205[Last branch of case expression omitted by PPAst.ppAst].
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2022/07/22]::
+
Fix for {issue-base}141[Pretty printing of Absyn in error message does
not respect fixity].
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2022/07/22]::
+
Fix for {issue-base}/68[Unable to interrupt execution by using `SIGINT`].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/07/06]::
+
Fixed some interfaces that did not agree with the **SML Basis Library**
specification.  Bugs bugref:318[] (`IEEEReal.decimal_approx` does not
match the Basis Library) and bugref:319[] (Type of `Real.fromDecimal`
does not match the Basis Library).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/07/05]::
+
Fixed bug bugref:316[] (`Real.fromManExp` does not return expected
value if `man = 0.0`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/07/05]::
+
Fixed bug bugref:317[] (Conversion from string to real does not
accept non-finite values).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/06/29]::
+
Fixed bug bugref:314[] (`IEEEReal.float_class` does not match the
Basis Library).  For some reason, the `NAN` constructor took an argument
in our implementation.  This code was probably an early design of the
API that was changed in the Basis Library specification, but not in our
code.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/06/29]::
+
Fixed a pretty printing issue that arises when printing nested
structure definitions.  For example, opening the `OS` structure
in the REPL, would result in an extra newline between the colon
and the `sig` keyword.
This behavior is not present in the legacy version.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/06/27]::
+
Adding support for generating a SIG_GC signal when there is a garbage
collection.  I have also added a function
+
[source,sml]
------------
  val signalThreshold : int -> unit
------------
+
to the `SMLofNJ.Internals.GC` structure that allows one to specify the
threshold for generating a signal.  The default is `1`, which means
that for any major collection a signal is generated.  Setting the
threshold to `0` means that minor collections also generate signals,
while setting the value to something greater than `1` will filter out
collections of younger generations.  Collections that happen while a
`sigGC` handler is running are ignored, which should not be an issue
for thresholds of `1` or greater.
+
These changes fix bugs bugref:65[] (Garbage collection does not trigger
`sigGC`) and bugref:291[] (Signals are not delivered for corresponding
events).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/06/17]::
+
Fixed bug bugref:290[] (Incorrect pattern matching for exceptons).
The fix involves changes to `FLINT/opt/lcontract.sml` (function `swiInfo`)
and `FLINT/opt/fcontract.sml` (function fcSwitch). The contraction of
a SWITCH with an constructor as subject is suppressed when the
constructor is an exception constructor, because for exceptions comparison
using the conrep field is inaccurate when the constructor is defined
by an exception identity declaration (e.g., `exception B = A`).
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2022/06/05]::
+
Fixed bug bugref:314[] (`IEEEReal.setRoundingMode` is a no-op on Linux).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/06/05]::
+
Fixed bug bugref:312[] (`CM.make` is unable to handle filenames that
contain a backslash).  We have changed the semantics of paths given
to the functions in the `CM` structure to be interpreted using the
native pathname syntax (instead of *CM*'s generic syntax).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/06/01]::
+
Fixed bug bugref:284[] (Compiler bug: Contract: UsageMap on 132).
The problem was the the `CPSTrans.cpstrans` function was generating
code for loading spilled parameters in reverse order.  In addition
to fixing the bug, added some detailed documentation of the code.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/05/20]::
+
Fixed bug bugref:310[] (Error when REPL tries to print value of type
`Posix.FileSys.ST.stat`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/05/10]::
+
Fixed bug bugref:306[] (`Word8VectorSlice`: mapping a subslice produces
wrong result or crashes SML/NJ).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2022/04/03]::
+
Fix a module compilation performance bug by removing `packStr` and
`packFct` from `Elaborator/modules/sigmatch.sml` (reducing the size of
that file by about 25%), and removing the call of `packStr`
(in function `constrStr`) in `Elaborator/elaborate/elabmod.sml`, replacing
it with a call to `Instantiate.instAbstr`. Goodbye at last to `packStr`!
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//====================================================================
== Version 2021.1; 2021/12/31

//--------------------------------------------------------------------
[2021/12/31]::
+
Switched over to the *LLVM* version of the compiler.  Doing so has
two major consequences:
+
--
* The **MLRISC** code generator that we have used for over 25 years
  has been replaced with one based on the https:llvm.org[**LLVM Libraries**].
* We have dropped support for 32-bit systems.  Since we do not
  have a 64-bit Windows port yet, this version only supports "Unix"
  systems on the *AMD64* processor (we have tested *Linux* and
  *macOS).
  A 64-bit Windows version is a high priority and we hope to include
  it in the next release.
--
+
In addition, we have changed the version numbering scheme to a
`YYYY.NN` scheme, where `YYYY` is the year of the release and
`NN` is the release number for the year.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/12/07]::
+
Fixed a bug in the way that non-printable `char` values were being
printed in the REPL.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/11/23]::
+
Remove last traces of the lambda splitting support from CM.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/11/23]::
+
Changed the `Binfile` structure (and `BINFILE` signature) to support both
the old binfile format and a new format (both formats are documented in
the `dev-notes/binfile.adoc` file).  We are stiull using the old format,
but will be switching to the new format soon.  The new format has a more
structured header and removes the vestigial support for the FLINT lambda
pickles.
+
The new header format includes a proper version number, which should
make migrating to new binfile formats easier.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/11/07]::
+
Committed changes to fix bug bugref:281[] (Redundant error messages for when a constructor
name is misspelled).  Revision r7357.
--
* Modified `Absyn.value` datatype by adding an error constructor
  `ERRORid`.
* Revised `ElabData/staticenv/lookup.sml` to simplify and improve some
  functions (`lookVal` -> `lookIdPath`, `lookValSym` -> `lookIdSym`) and added
  a function `lookIdSymOp` that returns an option.
* Revised `pat_id` and deleted `makeAPPpat` in `ElabUtil`.
* Revised `elabPat` in `ElabCore`.
--
+
owner:cs.uchicago.edu/~dbm[David MacQueen]

//--------------------------------------------------------------------
[2021/11/07]::
+
Committed a massive set of changes from "merge/base" working directory
that contained manually merged changes from "newmc" into a fresh
checkout of the trunk. Base version of the trunk was r7349, which was
tagged to produce `$smlnj/sml/tags/pre-merge`. The merged trunk
version is r7352.
+
The changes include:
+
--
* A completely rewritten match compiler that transforms absyn to
  absyn. The old match compiler files in
  FLINT/trans have been deleted. The new match compiler is documented
  in `dev-notes/match-compiler/match-compiler.txt` (and successor documents).
  The match compiler code is in the new directory
  `base/compiler/Elaborator/matchcomp`. `FLINT/trans/translate.sml` and
  related files were also extensively revised to work with the new
  match compiler.
* PLAMBDA/FLINT types modules in `FLINT/kernel` have been revised so
  that the signatures of the main modules (`Lty`, `LtyKernel`, `LtyDef`,
  `LtyBasic`, `LtyExtern`) are all disjoint. Function and record metadata
  stuctures that were in the FLINT structure (`FLINT/flint/flint.sml`)
  have been moved to `kernel/funrecmeta.{sig,sml}`. This involved minor
  edits to virtually all files in FLINT and a few in CPS.
  See `dev-notes/FLINT` for further documentation.
* Bug bugref:294[] (Compiler bug: Recover) has been fixed by deleting a
  few lines of code in `FLINT/opt/fcontract.sml`. Files `opt/collect.sml`
  and `opt/fcontract.sml`  been "clarified" to make them somewhat
  easier to maintain/debug.
* The `VarCon:VARCON` structure defined in `ElabData/syntax/varcon.{sig,sml}`
  has been renamed Variable: VARIABLE (`ElabData/syntax/variable.{sig,sml}`),
  since it no longer contains functionality relating to data constructors.
* The regression tests (`$smlnj/tests`) were run and a few true
  regressions were fixed, including a type error
  (`bugs/tests/bug0573.sml`). Many regression failures remain that are
  due to differences in the pretty printers, reworded error messages,
  and new printing conventions for overload scheme type variables.
  Some reference test outputs were updated, but at some point all new
  outputs should be generated. But first, signature printing should
  be redesigned and reimplemented.
--
+
owner:cs.uchicago.edu/~dbm[David MacQueen]

//--------------------------------------------------------------------
[2021/09/23]::
+
Changed the *binfile* representation to remove the pickling of
the *FLINT* intermediate representation.  The purpose of this
mechanism was to support cross-module inlining, but it has not
be enabled for many years.  Removing it is the first step toward
migrating the pickling infrastructure to use *ASDL*.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/09/23]::
+
Changed the way that versions are identified to allow a version suffix
(e.g., "-rc1" for "release candidate 1").  I removed the bump-release
mechanism, which might has served a similar purpose, but was restricted
to integer suffixes and has not been used in recent memory.  Also changed
the `SMLNJVersion` structure, which is generated by the `versiontool`.
The new interface supports the version suffix and includes both a build
date and a release date in the `version` information record.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.99.2; 2021/09/23

//--------------------------------------------------------------------
[2021/08/18]::
+
Fix a benign bug where the size of a floating-point spill record was twice
as large as necessary on 64-bit systems.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/08/10]::
+
Split out the `Real.toLargeInt` implementation into target-word-size
versions (the `Real64ToIntInf` module).  For 64-bit targets, the new
version uses the bit representation of the real number to compute the
result.  The 32-bit version is the old code that uses floating-point
operations.  This change fixes bug bugref:279[] (`Real.toLargeInt` returns
zero for anything in range `[-512,512]`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/04/29]::
+
In the translation from Absyn to PLambda, there was a function (`inlops`)
that was used to build the primop and type data structures for numeric
types.  This function was being called for every primitive operator,
even though its results only depended on the numeric type.  I added
a hash table to cache the results indexed numeric kind.  This change
speeds up the compiler by about 3% (__e.g.__, compiling the compiler
went from 58s to 55s on a MacBookPro with a 2.4GHz Intel i9 processor).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.99.1; 2021/04/12

//--------------------------------------------------------------------
[2021/04/10]::
+
Changed the *AMD64* frame layout to include a word to hold the
`Overflow` exception.  This value is used by the *LLVM* backend
to generate the exception for checked arithmetic operations.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/04/10]::
+
Added support for running *SML/NJ* on *M1* Macs via the *Rosetta2*
emulator.  The change is to identify the *arm* processor as *amd64*
in the `config/_arch-n-opsys` script.  Note that while the system
basically seems to work okay under rosetta, trying to run the `makeml`
command after having compiled the complier caused a crash.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/04/10]::
+
Some minor restructuring of the logic in the generic installer.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/03/25]::
+
Fixed a bug with how *FLINT* numeric types were being translated to *CPS*
types.  Specifically, types that were smaller than the default integer
size (_e.g._, `word8`) should have been marked as having a tagged
representation.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/02/12]::
+
Fix for bug bugref:280[] (110.99 `config/install.sh -64` fails on macOS 10.15.7).
I was unable to reproduce this problem, but after some investigation, it
appears that the problem was inconsistent build tools being picked up from
the user's path.  To protect against this issue, I made the paths to the
*ar* and *ranlib* tools absolute.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2021/01/12]::
+
Fixed a serious performance bug in the implementation of the `CharBuffer`
and `MonoBuffer` structures.  Essentially, if one did not reserve sufficient
space for the contents, it could take quadratic time to fill the buffer.
We now grow the buffer by a factor of 1.5 of its current size, with an
upper bound on the extra growth of 256K.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.99; 2020/12/24

//--------------------------------------------------------------------
[2020/12/23]::
+
Changed the layout of the *SML* stack frame on the *AMD64*
architecture to make it compatible with the way that *LLVM*
spills registers.  Essentially, this just involved swapping
the order of the swap area and the ML stuff.  We took this opportunity,
however, to localize up the representation of this information in
the compiler.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/12/23]::
+
Changed the format of the "magic string" in the header of binfiles.
The new format is "__arch__``-``__version__", where the architecture
name is limited to at most seven bytes and the version is limited to
at most eight bytes.  The string is padded with spaces to a total
length of 16 bytes.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/12/22]::
+
Various pretty-printer bug fixes:
+
--
* bug bugref:274[] (Minor pretty printing glitch when printing
  structure specs)
* bug bugref:276[] (Missing option to control extra newlines in REPL)
* bug bugref:277[] (Excess white space when pretty printing a module
  signature)
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/12/19]::
+
Fixed bug bugref:254[] (`Real.fromLargeInt` produces negative results).
The problem was because the digit size for `IntInf.int` is only one bit
smaller than the default int and the scaling factor `rbase` was being
computed using the `InlineT.Real64.from_int` function (so `rbase`
ends up being negative). Thus it would return incorrect results
whenever the IntInf representation involved more than one digit.
This is a bug on both 32-bit and 64-bit systems. The fix was to
switch to using `InlineT.Real64.from_int{32,64}` to convert `rbase`
and digits to real values.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/12/19]::
+
Fixed bug bugref:267[] (Returns an incorrect result for a calculation
on `Position.int` for 32-bit mode). The problem was that on 32-bit
machines, 64-bit division is implemented by the IntInf module with
the result then being converted to 64-bits. The conversion used did
not test for overflow in the result.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/10/13]::
+
Changed the semantics of the spans returned by *ml-ulex* so that the
second component of a span is the position of the rightmost character
in the token (instead of the character following the token).
Specifically, the span latexmath:[(p_1, p_2)] specifies the
latexmath:[p_2 - p_1 + 1] characters that start with the character at
position latexmath:[p_1] and run to latexmath:[p_2] (inclusive).
This change avoids a potential problem when the span of a token ends
at the last character in a file (when the input is spread across
multiple files).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/09/10]::
+
Simplified the *binfile* representation by removing the option of
having multiple code objects.  Many years ago, we would split the
code for a compilation unit into multiple independent functions
so that the garbage collector could reclaim code that was only
executed once (or was not referenced).  The actual splitting of
the code in the `CpsSplitFun` functor (`CPS/clos/cps-split.sml`)
was replaced by a dummy implementation at some point, so we have
not been generating multiple code objects for some time.  Therefore,
we have simplified the code generator to assume only one code
object and have changed the *binfile* import/export code to only
support a single code object per *binfile*.
+
Also made this change to the bootstrap loader (`kernel/boot.c`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

== Version 110.98.1; 2020/08/25

//--------------------------------------------------------------------
[2020/08/25]::
+
Reverted some of the pretty printing changes that were made in 110.98
to the 110.97 version (the renaming of `PrettyPrintNew` to `PrettyPrint`
and the directory reorganizations were unchanged).  These changes
fix bugs bugref:266[] (Pretty printing regression in SML/NJ 110.98),
bugref:268[] (Polymorphic Type Pretty Printing Regression), and
bugref:271[] (pretty printer regression for structure binding).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/08/02]::
+
Fixed bug bugref:269[] (`Word64.fromString` causes an `Overflow` for
greater than 2^32^-1).  This bug was the result of constants from the
32-bit version of the code not getting updated for the 64-bit version.
Scanning of both hexadecimal and octal representations of both integers
and words were affected.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/07/22]::
+
Added an additional lowering pass for the `STREQL` primop.  This
primop is generated to implement pattern matching against string
literals.  Previously it was unrolled in the *MLRISC* code generator,
but we now do the unrolling in *CPS*.  The reason for this change
is that implementing the unrolling in the *LLVM* code generator
would be complicated because of the need to introduce phi nodes
in one of the branches.
+
The unrolling in *CPS* is somewhat different from before in that
we now bake the literal string being tested into the equality tests.
+
Also changed the representation of the primop to include the string
being tested against and removed the `STRNEQ` primop.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.98; 2020/07/16

//--------------------------------------------------------------------
[2020/07/10]::
+
Implemented https://github.com/SMLFamily/BasisLibrary/wiki/2020-001-Addition-of-Universal-module[
Basis Library proposal 2020-001 (Addition of Universal module)].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/07/10]::
+
Changed the `config/install.sh` script so that the default size
is 64 bits for any machine that reports its machine as "``x86_64``."
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/07/10]::
+
Fixed bug bugref:260[] (Perform divide on `Position.int` crashes
with FPE on Linux).  The fix required adding SIGFPE as a second
source of `Overflow` exceptions on Linux/amd64 machines.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/07/08]::
+
Fixes for structure and signature pretty printing problems that were
introduced in the extensive pretty printer/pretty printing
modifications around revision 6291.
+
Files affected include `ElabData/modules/ppmod.sml`,
`ElabData/types/pptype.sml`, `TopLevel/print/ppdec.sml`,
and ``Basics/print/pputil.``{``sig``,``sml``}.
+
The pretty printing for modules still seems quite fragile, so there
are likely to be more pretty printing problems to be fixed later. In
particular, pretty printing of functor and functor signature
declarations haven't been tested.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2020/07/07]::
+
Added a new _lowering_ pass following *CPS* optimization, but before
closure conversion.  This pass includes the previous passes for
64-bit operations on 32-bit matchines and for conversions involving
`IntInf.int`.  It also adds lowering for `div` and `mod` to native
machine division (_i.e._, `quot` and `rem`) and for trapping conversions.
+
The purpose of this change is to simplify code generation in preparation
for migrating to a **LLVM**-based backend.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/07/06]::
+
Fix for bug bugref:261[] (Weird "calc_strictness" message being printed).
Rewrote the function `ElabUtil.calc_strictness` and moved it to
`TypesUtil.calcStrictness`.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2020/07/02]::
+
The `HTMLDev` structure in the pretty-printing library has been
moved into its own library (`pp-extras-lib.cm`) and renamed as
`HTML3Dev`.  This change removes the dependency of `pp-lib.cm`
on `html-lib.cm`, which allowed us to remove all mention of
`html-lib.cm` from the compiler *CM* files.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/07/02]::
+
Completed the removal of the trigonometry operators from the primops.
This change also allowed the removal of extension support from the
*MLRISC* code generator for the x86.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/07/01]::
+
Disabled the use of the hardware instructions for the basic trig
functions on the *x86*.  Doing so simplifies cross compilation
from non *x86* hosts and also paves the way to removing the operations
from the compiler's primitive operators.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/06/30]::
+
Improved the *CPS* contraction phase by adding strength-reduction
optimizations to `ContractPrim`.  These include recognizing when
multiplications and divisions by powers of 2 can be replaced by
shifts.  Previously, these sorts of optimizations were provided
by *MLRISC*, but we plan to simplify the *CPS* IR prior to code
generation by replacing `div` and `mod` operations with native
machine arithmetic, which would prevent *MLRISC* from making the
optimizations.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/05/16]::
+
The *MLRISC* instruction selector for the *x86* and *amd64* targets
erroneously assumed that the `idiv` instruction sets the `OF` (overflow)
condition code when dividing the largest negative number by ``~1``.
In fact, such a division operation traps, which is okay, because the
runtime system maps the trap to the `Overflow` exception.  Since the
check for overflow is unnecessary, it has been removed from the files
`MLRISC/amd64/mltree/amd64-gen.sml` and `MLRISC/x86/mltree/x86.sml`.
+
Note that *MLRISC*'s non-trapping signed division operations can
actually trap on overflow, but this was true before this change.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/05/16]::
+
Changed the semantics of the `--debug` command-line option for *ml-antlr*.
Previously this option replaced the actions with a print expression, but that
limited its usefulness because of type errors in the generated code.  The new
behavior is to preserve the existing actions and just add the printing code.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/04/27]::
+
Added a pass to the elaborator that check for variables that are
bound, but never referenced.  This check can be controlled by
the `Control.Elab.unusedWarn` flag. Unused top-level variables
are not reported (unless they are bound in the local part of
a local declaration).
+
The check is currently disabled because of false positives
caused by a transformation in the type checker.  For example,
the following function declaration: +
+
[source,sml]
------------
fun foo n = let
      fun f x = g x - 1
      and g x = f x + 1
      in
	f n
      end;
------------
gets represented by the following `Absyn`: +
+
[source,sml]
------------
val foo = let
      val foo = (fn n => let
	      local
		val tmp = let
		      val rec f = (fn x => Int.- (g x,1))
			  and g = (fn x => Int.+ (f x,1))
		      in (f,g)
		      end
	      in
		val f = #1 tmp
		val g = #2 tmp
	      end
	    in f n
	    end)
      in foo
      end
------------
where the instance of `g` bound to `#2 tmp` is unused.  This transformation
is done by the `wrapRECdec` function.
The unused-variable implementation was influenced by
https://gist.github.com/jvanburen/2ef1a722fba13fc169b670ba6392da52[Jacob Van
Buren's patch for Version 110.82]. +
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/04/24]::
+
The `LambdaVar.lvar` type is represented as an integer; since the earliest
days of the compiler this representation has been concrete, which meant
that the type system was not able to provide any guarantees that `int`s and
`lvar`s were not being mixed up.  As of this change, `LambdaVar.lvar` is
now an abstract equality type (internally, it is still and `int`).
Some comments about the changes: +
+
--
 * The `LambdaVar` structure now includes substructures that implement
   hash tables (`LambdaVar.Tbl`), finite maps (`LambdaVar.Map`), and
   finite sets (`LambdaVar.Set`).

 * most of the changes involved replacing `IntHashTable`, `IntRedBlackSet`,
   `IntRedBlackMap` with the equivalent substructures that were added
    to the `LambdaVar` structure (_e.g._, `IntHashTable` ==> `LambdaVar.Tbl`).

 * there were a few place where debugging code assumed that lvars
   could be printed as integers.

 * the pickling code requires a mechanism to convert between integers and
   lvars; this is the one place where the abstraction is broken.

 * the worst abuse of the fact that the lvar type was `int` was in the
   code generator, where arithmetic was used to generate a unique negative
   number that could be used as a hash key, so that a given `lvar` could
   be mapped to two different labels.  I fixed this by using two tables.
--
owner:cs.uchicago.edu/~jhr[John Reppy]

[2020/04/24]::
+
Fixed bug bugref:256[] (`Ref.exchange` incorrect). The original
source of the bug was the *Basis Library* sample code, which
has also been fixed.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.97; 2020/04/21

//--------------------------------------------------------------------
[2020/04/21]::
+
Changed the printing of tyvars; _e.g._, an `OVLDV` tyvar introduced
by an occurrence of the overloaded operator "++*++" that also
acquires the equality attribute will be printed as ++''Z[OL(*)]++.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2020/04/20]::
+
Eliminated AbsDec and ABSdec constructors
+
--
    * Eliminated `AbsDec` constructor in `Parse/ast/ast.`{`sig`,`sml`}
      and `ABSdec` constructor in `ElabData/syntax/absyn.`{`sig`,`sml`}
      The "abstraction" declaration that these constructors
      implemented was in SML/NJ 0.93, but was eliminated in favor
      of opaque "sealing" signature ascription after SML '97.

    * Eliminated all other occurrences of these constructors
      throughout the compiler (Front End, FLINT, and cm).
--
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2020/04/20]::
+
File structure reoganization: the top-level `compiler/Semant`
directory was eliminated. Remaining relevant subdirectories
were `Semant/pickle`, which moved to `ElabData`, and `Semant/prim`,
whose two files, `prim-env.sml` and `primop-bindings.sml` moved to
the existing `ElabData/prim` directory. CM files `compiler/core.cm`
and `ElabData/elabdata.cm` changed accordingly.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2020/04/20]::
+
Fixed bug bugref:220[]
+
--
    * Major redesign of the overloading resolution mechanisms.
      Changed syntax of overload declaration (partly deferred to
      110.98). Changed OVLDvar in VarCon.var, added files
      overloadclasses.sml and overloadvar.sml to Elaborator/types.
      Changed Types.tvKind in ElabData/types/types.{sig,sml},
      splitting OVLD tvKind into OVLDV (overloaded
      variables/operators), OVLDI (overloaded int literals) and
      OVLDW (overloaded word literals). Modified treatment of the
      overload metavariables in Unify (Elaborator/types/unify.sml).

    * Changed printing of overload type metavariables (unification
      type variables (`Types.tyvar`)).

    * Files:
      `ElabData/types/types.`{`sig`,`sml`}
      `ElabData/types/overloadclasses.sml`  (new)
      `ElabData/types/overloadvar.sml` (new)
      `ElabData/types/overload.sml`
      `Elaborator/elaborate/elabcore.sml`
--
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2020/04/09]::
+
Fixed bug bugref:214[]
+
--
    * Changed printed message when a VALvar binding is shadowed to
      print "`<hidden>`" (function `ppVar` in `MiscUtil/print/ppdec.sml`).

    * Minor cleanup of `dontPickle` function in `Semant/pickle/pickmod.sml`.
--
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2020/04/08]::
+
Fixed bug bugref:209[]
+
--
    * Added function `checkForbiddenCons` to `ElabUtil`
      (`Elaborator/elaborate/elabutil.{sig,sml}`) that checks if
      a symbol is in the forbidden constructor set (`it`, `true`,
      `false`, `nil`, `::`, and `ref`).
    * Modified `elabEXCEPTIONdec` to check for forbidden exception
      constructor names. Rewrote function `elabEb` to simplify.
    * Added a test for forbidden constructor names in function
      `elabConstr` within `elabDB`.
    * Changed specs for types list and bool to datatype replication
      specs in `system/Basis/Implementation/{list,bool}.sig`
      to avoid an error caused by the occurrence of "forbidden"
      constructors.
--
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2020/04/07]::
+
Some clean up in the `ml-lex/lexgen.sml` code.  Replaced the one-off
implementation of finite maps with the `RedBlackMapFn` functor from
the *SML/NJ Library*.  Also got rid of the uses of polymorphic equality
by changing token equality tests to pattern matching.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/04/05]::
+
Turned several functors (`ElabModFn`, `ElabTopFn`, `SigMatchFn`, etc. into
structures and removed the redundant functor application files (and
the directories) in `Semant/elaborate` and `Semant/modules`.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2020/04/05]::
+
Fixed bugs bugref:195[] and bugref:196[]
+
--
    * bugref:195[]: added missing `DOdec` case in function `getDeclOrder` in
      `ElabMod` (Elaborator/elaborate/elabmod.sml l. ~563)
    * bugref:196[]: modified `elabDOdec` in `Elaborator/elaborate/elabcore.sml` to
      return the empty Static environment (`SE.empty`)
--
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2020/04/02]::
+
Various minor changes related to the *heap2exec* and *heap2asm*
programs.
+
--
    * Modified the `config/install.sh` script to remove `bin/heap2exec`
      when the required helper `bin/heap2asm` is _not_ installed.
    * Added `-static` and `-dynamic` as options to *heap2exec*
      (these are the same as `--linkwith-a` and `--linkwith-so`)
    * Rewrote *heap2asm* be a bit more future-proof.
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/04/02]::
+
Addressed bug bugref:247[] (@SMLVersion should report 64/32 bit) by
adding a new command-line option (`@SMLwordsize`) to the `.run-sml`
command script.  Specifying this option will cause the the wordsize
to be printed (either `32` or `64`) and then the program will exit.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/03/19]::
+
Fix for bug bugref:252[] (Boyer Benchmark Compile Failure).  This crash
was caused by a typo in the `CPS/main/build-literals.sml` code that
caused an incorrect opcode to be generated for `SAVE`/`LOAD`
instructions when the offset was `>= 256`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/03/04]::
+
Fixed the calculation of the maximum array/vector length for
64-bit targets.  We had been using the calculation for 32-bit
targets.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2020/01/14]::
+
Fix for bug bugref:245[] (Lazy data types result in Compiler Bug error).
The problem was that a number of symbols (__e.g.__, `deref`) had been
dropped from the `_Core` structure, but were required to support
the lazy (and profiling) features in the compiler.  The symbols have
been reinstated and a comment has been added to explain why they
are being included.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/12/23]::
+
Fix for bug bugref:244[] (Compiler bug: PPObj: ppFields in ppval.sml).
The code generator was using the wrong length tag for raw64 records
on 64-bit machines (twice the length).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/12/21]::
+
Clean up various issues in the configuration/build machinery for **asdl**.
This includes a fix for bug bugref:240[] (Non-default 64-bit installation
build failure)
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/12/18]::
+
Fix bug bugref:239[] (`Date.toTime` is incorrect (by a factor of 10E9)).
Thanks to Johannes 5 Joemann for both the report and fix.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.96; 2019/12/13

//--------------------------------------------------------------------
[2019/12/12]::
+
Bug fix for a problem where ^C (and other signals might be ignored).
The fix is to use word-sized fields in the VProc state vector so that
the word-sized move operations in the assembly code do not clobber
adjacent fields.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/12/12]::
+
Fix for bug bugref:234[] (Converting NaN to a string causes an infinite
loop on 64-bit machines).  The problem was in `MLRISC/amd64/mltree/amd64-gen.sml`,
which was not generating comparisons that work correctly when the
arguments are unordered.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/12/12]::
+
Removed assertion checking from the **amd64** runtime makefiles.  It
has not turned up any errors since 110.94 was released, so we will
assume that things are working the way that they should.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/12/01]::
+
Bugfix for bug bugref:237[] (**heap2exec** script fails on 110.95).
The fix was provided by Kirill Boltaev.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/11/23]::
+
Changed the default installation size to 64 bits on **macOS** 10.14
Mojave and later.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/11/14]::
+
Fixed some code rot in the *eXene* sources (bug bugref:233[]).  With
the `LargeWord` module changing from `Word32` to `Word64`, there were
a few places were things broke.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/11/14]::
+
Added support for 64-bit executables on **FreeBSD**.  As part of this
effort, we fixed a couple of regressions (makefile issues) for the
32-bit version on **FreeBSD** that were introduced when the `X86.prim.asm`
file was rewritten.  We also switch from *BSD* signal handling to
*POSIX* signal handling, since that is what we use for most other systems.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/11/12]::
+
Fixed `config/install.sh` script, which was not passing the size
option to the `.link-sml`, which caused confusion for the "**-64**"
flag.  This problem was later reported as bugs bugref:235[] and
bugref:236[].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/11/10]::
+
Many years ago, *SML/NJ* had a bytecode interpreter, but it was mostly
removed from the system a long time ago.  There were, however, some
remnants of it in the runtime system.  These have now been removed.
+
Having made this change, the distinction between the "target" and
"host" architectures is no longer necessary.  Therefore, these have
been merged into a single architecture property.  The effects of this
merge are as follows:
+
--
* the `TARGET_xxx` and `HOST_xxx` C-preprocessor symbols have been
  replaced with a single `ARCH_xxx` symbol in the runtime system.
+
* The `SMLofNJ.SysInfo` structure now provides `getArchName` and
  `getArchSize` functions.
+
* The following `SMLofNJ.SysInfo` functions are deprecated and will
  be removed in 110.97: `getHostSize`, `getHostArch`, and
  `getTargetArch`.
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.95; 2019/11/09

//--------------------------------------------------------------------
[2019/11/09]::
+
Fix for bug bugref:230[] (New literals-lifting code does not handle
pair of reals).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/11/09]::
+
Simplified the runtime-system build rules for Cygwin.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/11/08]::
+
Created the script `config/prepare-win-install.sh`, which implements
the fetching and unbundling of source and bin files in preparation
for a Windows installation.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/11/07]::
+
Fix for bug bugref:229[] (`Real.fromString` errors). This bug was
actually two unrelated issues.  The problem that `Real.toString`
returns `Real.posInf` for `0.0e123213213123213123123` has been
fixed in the `RealScan` module (`system/basis/Implementation/real-scan.sml`).
The second bug was a regression introduced in 110.93, where the
`SIGFPE` signal was specified as the result of the `into` instruction,
whereas **Linux** actually signals `SIGSEGV` for `into`.  Note that
there may be a related issue of **BSD** systems, where `SIGBUS` might
be the signal, but we need access to a test machine to verify.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/11/07]::
+
Fix for bug bugref:230[] (segmentation fault when compiling MLton sources
with SML/NJ 64-bit).  The problem was that when a large vector was
being created, the assembly code did not correctly restore the stack
state before trying to call the runtime system to do the allocation.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/11/04]::
+
The runtime now uses `MAP_ANON` for allocating memory on 64-bit Linux.
This change fixes a problem with versions of Linux that do not allow
access to `/dev/zero` (such as on **ChromeBooks**).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.94; 2019/10/31

//--------------------------------------------------------------------
[2019/10/23]::
+
Modified the generic installed (`base/system/smlnj/installer/generic-install.sml`)
to support conditional targets.  You can now write tests like
+
[source]
--------
if UNIX
  unix-utils
endif
--------
+
The symbols that can currently be tested for are `SIZE_32`, `SIZE_64`,
`UNIX`, and `WINDOWS`.  See the `config/targets` file for more details.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/23]::
+
Fixed bug bugref:227[] (CPS contraction is taking an excessive amount
of time on word8 basis test).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/22]::
+
Modified the CPS contraction phase to optimize the case where a
numeric conversion is applied to a constant value.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/21]::
+
Modified the Unix installer script (`base/system/smlnj/installer/nix-install.sml`)
to pass a size argument to the configuration script.  This argument is used
by the **ASDL** configuration.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/21]::
+
Overhauled the installation script (`config/install.sh`) and various
script templates (__e.g.__, `config/_run-sml`) to allow setting the
default size.  The `config/install.sh` script now supports the following
arguments:
+
--
  **-default** __size__::
    specify the default size for the **sml** and other commands, where
    __size__ is either **32** or **64**.

  **-32**::
    install the 32-bit version of the system.

  **-64**::
    install the 64-bit version of the system.
--
+
It is possible to install both versions in the same location by running
the `install.sh` script twice.  For example, the commands
+
[source,shell]
--------------
% config/install.sh -32
% config/install.sh -default 64
--------------
+
will install both versions with the 64-bit version as default.  One
would then use the command **sml -32** to run the 32-bit version of
the system.  Note that the default version must be installed second.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/21]::
+
Added support for the **-64** flag to the `fixpt` script in `base/system`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/17]::
+
Added support for the **-64** flag to the `cmb-make` script in `base/system`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/17]::
+
Renamed the `REAL` representation constructor to `Raw64`, which matches
what is going on in the runtime system.  Also renamed the `toReal` function
to `toReal64`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/15]::
+
Updated the `SMLofNJ.SysInfo` structure by removing constructors from the
`oskind` datatype that correspond to obsolete systems.  Also added a
`getHostSize` function that returns the host architecture's native word
size in bits (__e.g.__, 32 or 64).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/13]::
+
Added the **-64** flag to the `testml` script in `base/system` and
to the `.run-sml` script.  Thus, one will be able to specify the
32-bit version of SML/NJ using the command **sml -32** and the
64-bit version using the command **sml -64**.  Currently, 32-bits
is the default, since the 64-bit system is unstable.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/13]::
+
Removed obsolete operating systems from the `SMLofNJ.SysInfo.os_kind`
datatype.  This change reduces the type to two constructors: `UNIX`
and `WIN32`.  Also added a function `getHostSize` to the `SysInfo`
structure, which returns the host word size in bits (*i.e.*, either
`32` or `64`).  The word size is now reported in the compiler's
banner message at startup.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/12]::
+
Fixed bug bugref:130[] (failure to raise `Bind` exception). Added
a function `refutable` to `ElabData/types/typesutil.{sig,sml}` and
used it to limit type generalization of val bindings in
`Elaborator/types/typecheck.sml`.
The fix does not deal properly with refutability of OR patterns, but
OR patterns in val bindings is a dubious feature.
+
This change also fixes bug bugref:188[] (Missing warning for
nonexhaustive valbind patterns), bug bugref:190[] (Unexpected exception
in SML/NJ with invalid list pattern match), and bugref:199[] (Compiler
bug in pretty printing of result).
+
owner:cs.uchicago.edu/~dbm[David MacQueen]

//--------------------------------------------------------------------
[2019/10/04]::
+
Modified the **cmb-make** script to support passing compiler control
flags to the build command.  The flags should be specified after the
path to **sml** command (if it is given).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/04]::
+
Finished the implementation of the new literal bytecode engine.
There is a control flag (`Control.CG.newLiterals` that allows
switching between the old and new bytecodes).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/04]::
+
Fix for bug bugref:225[] (`Math.ln` giving erroneous answers on Windows).
The problem was an inconsistency in the way the Unix and Microsoft
assemblers interpreted the addressing mode for the `FLD` instruction.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/10/03]::
+
Clean up in the Basis Posix library code (both SML and runtime) to
be consistent about when the `SysWord.word` type is being used to
communicate information between SML code and the runtime system.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.93; 2019/09/05

//--------------------------------------------------------------------
[2019/09/04]::
+
Add support for specifying a 32 or 64-bit target as command-line option
to the `.arch-n-opsys` and `.link-sml` scripts.  The default size is
currently 32-bits, but that will change once 64-bit support is solid.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/09/03]::
+
Generalize code generation for conversions involving tagged integers/words,
where the size is _not_ the default integer size.  This situation only
occurred for `Word8.word` values on 32-bit targets, but also occurs for
32-bit values on 64-bit targets.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/09/02]::
+
Rewrote the expansion of the `INLLSHIFT`, `INLRSHIFTL`, and `INLRSHIFT`
primops (`compiler/FLINT/trans/transprim.sml`).  The expansion process
now correctly handles shift operations on types that are smaller than
the default tagged-integer size.  This change also allows the `Word8`
shift operations to be inlined.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/09/02]::
+
Fixed a bug in the constant folding of arithmetic-right-shift operations.
The sign was not getting extended for words when the most-significant-bit
was set.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/08/25]::
+
Fixed a bug in the `Real.toManExp` function (the exponent was off
by one, which meant that the mantissa was two times its expected
value).  This fix also fixes a problem in `Real.toLargeInt`, where
the function would go into an infinite loop in some cases.
+
[NOTE]
.2022/06/29
====
This change probably also fixed bug bugref:208[] (`Real.toManExp`
produces incorrect results in some cases).
====
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/08/24]::
+
Fixed bug bugref:173[] (`OS.Process.sleep` only works with whole numbers).
For systems that have finer-grain sleep function, such as the
`nanosleep`(2) system call, the `OS.Process.sleep` and `Posix.Process.sleep`
functions now support sub-second granularity.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/08/18]::
+
Restructured the CPS contraction phase to make the fusion of
integer/word conversions more uniform.  Also fixed a bug
where `Int32.fromLarge(Word32.toLargeInt 0wxffffffff)` would
return `~1` instead of raising `Overflow`.  The problem was
that `TEST(m,n) o COPY(n,p)` was getting fused to `COPY(m,p)`
when `m = p`, instead of `TRUNC(m,p)`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/08/14]::
+
Int64 comparisons were not always correct, which lead to some positive
values being printed as negative numbers (basically when the sign
bit of the lower word was set).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/08/13]::
+
Added `Unsafe.IntInf` structure, which provides access to the
internal representation of the `IntInf.int` type.  Note that
this representation may change in the future.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/08/12]::
+
Fixed bug bugref:223[] (Incremental Build fails on Windows).  There was
a missing `CloseHandle()` when getting a file's timestamp.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.92; 2019/08/10

//--------------------------------------------------------------------
[2019/08/08]::
+
Changed `base/system/allcross` script to use `cmb-cross` script.
Also modified the `cmb-cross` script to build compressed tar
files, when given the `-z` option, and to clean up intermediate
files.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/07/16]::
+
Restructured the **amd64** machine-code generation implementation and
filled in many of the missing encodings.  It should be complete for
**SML/NJ** code generation, but needs more work to support the full set
of operations described in the `amd64.mdl` file.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/07/16]::
+
Some cleanup in the **x86** MLRISC backend.  Removed the `MULB`,
`MULW`, and `MULL` unsigned-multiplication instructions, since they
are not binary operations.  The `MULL` instruction is covered by
the `MULL1` constructor in the `multDivOp` datatype.  The same change
was applied to the **amd64** backend.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/07/15]::
+
Many changes to the **amd64** machine description:
+
--
* Removed the `PUSHB`, `PUSHW`, and `PUSHL` instructions, since the matching
   `POP` operations are not supported.
* Removed the `CALLQ` operation, since it is the same as `CALL`.
* Removed the `CLTD` and `CQTO` operations, since those names are just
   synonyms for `CDQ` and `CDO`.
* Replaced the `INTO` operation (which is not valid in 64-bit mode) with
   `INT of byte`.
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/07/13]::
+
New script for cross compiling to other architectures; the script
is still called `cmb-make`, but now supports target-specific
dependencies in the front-end (_i.e._, representation of numeric
types and endianess).  The cross compilation scheme was developed
by Matthias Blume and then encoded in a script.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/07/11]::
+
The runtime system now builds for the amd64 architecture.  Most of
the changes relate to the difference between the flat BIBOP on 32-bit
platforms and the two-level BIBOP on 64-bit platforms.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/07/09]::
+
Fix bug bugref:224[] (`Word64.fromLargeInt` fails).  The problem was
an incorrect record kind in `CPS/opt/infcnv.sml` (it was `RK_RECORD`
instead of `RK_RAWBLOCK`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/07/08]::
+
Changed the `rep` datatype constructor `Word32` to `Raw`  (which
covers both 32 and 64-bit numbers on 32-bit platforms).  We now
check the length of the raw object when converting to an
concrete numeric type.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/28]::
+
Removed the use of runtime-type passing for polymorphic arrays.
The effect of this change is that code that uses the `Array.array`
type will be faster when the element type is **not** `real` (__e.g.__,
sorting an `Int32.int array` was 1.2 times faster), but
slower when the type is `real`.  Use the monomorphic type
`RealArray.array` for best performance on arrays of reals.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen] and
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.91; 2019/06/20

//--------------------------------------------------------------------
[2019/06/20]::
+
We added a new primop, `REAL_TO_BITS` that casts a floating-point value to the
same-size word value.  This primop allows the Assembly.logb function to be
implemented in *SML*. +
+
We have also refactored the implementation of the `Math` structure to share
common code across the versions that are specialized for different levels of
hardware support.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/19]::
+
Rewrote the assembly code for the x86 and AMD64 targets.  Previously, there
were separate source files for Unix and Windows; these have been replaced
by a single common file (one for each architecture).  The `assyntax.h` file
has also been replaced by `x86-syntax.h`, which covers both the x86
and AMD64 on both UNIX and Windows. +
+
The `AMD64.prim.asm` file now compiles, although there are a few minor
issues that will have to be fixed once we have a working code generator.
We have also fixed a number of issues in the garbage collector related
to the use of the 2-level BIBOP on 64-bit targets.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/18]::
+
Some cleanup in the interval-timer code.  In keeping with the other
time-specific functions, I have switched the runtime-system API to
use unsigned 64-bit nanoseconds to specify time values.  I have also
added an implementation for `c-libs/smlnj-runtime/itick.c`, which
was missing.   Lastly, moved the Windows-specific file `win32-timers.c`
from `runtime/kernel` to `runtime/mach-dep`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/16]::
+
Added 64-bit implementations of the target-specific **Basis Library**
modules in directory `Basis/Implementation/Target64Bit`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/16]::
+
Added `PackWord64Big` and `PackWord64Little` structures to Basis Library.
Note that the implementation of these is target-specific.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/16]::
+
Added `bigEndian` flag to the `TARGET` signature.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.90; 2019/06/12

//--------------------------------------------------------------------
[2019/06/12]::
+
Fixed the Concurrent ML library to use 64-bit positions (both Unix
and Windows) versions.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/11]::
+
Moved the year offset from SML to the runtime system.  This change is
necessary because Windows uses 1601 as year 0, whereas UNIX uses 1900.
We have also switched to using unsigned 64-bit times in nanoseconds as
the interface between the Basis code and runtime system.  This change
is consistent with the other places where time values are communicated
between the runtime and SML code.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/07]::
+
Fixed a problem with CM's symbol filtering (see bug bugref:222[]).
+
The problem could manifest itself when a library `l2.cm` imported two
symbols `A` and `B` from `l1.cm` and then exported the same `A` but a
different `B` (which could have been defined in terms of the imported
`B`).  Moreover, for the problem to occur both `A` and `B` within
`l1.cm` must have come from the same SML source file.
+
With the above setup, when running
[source,sml]
------------
CM.make "l2.cm";
------------
it was possible that instead of seeing the new `A` defined within
`l2.cm` one would still see the original version that came from
`l1.cm`.
+
owner:people.cs.uchicago.edu/~blume[Matthias Blume]

//--------------------------------------------------------------------
[2019/06/04]::
+
Various 64-bit porting changes to the **Windows** implementation of
the **Basis Library** and runtime system:
--
* Add a target-specific `Handle` structure to support the `HANDLE` type,
  which is a pointer-sized word value.
* Changes to support the use of 64-bit file positions.
* Replaced pairs of argumnents representing time values (seconds and
  microseconds) with a single 64-bit count of microseconds.
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/04]::
+
Implemented https://github.com/SMLFamily/BasisLibrary/wiki/2019-001-Correction-to-PRIM_IO[
Basis Library proposal 2019-001 (Correction to the PRIM_IO signature)].
This proposal changes the return type of the `avail` function in a reader to
be `Position.int option`, which is necessary to support large files.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/03]::
+
Added primop support (`PTR_TO_WORD` and `WORD_TO_PTR`) for the
`c_pointer` type that was added in 110.89.  These primops are
exposed in the new `InlineT.Pointer` structure.  We define a
`PointerImp` structure that is used inside the Basis implementation
and a `Unsafe.Pointer` structure that is visible to users.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.89; 2019/06/01

//--------------------------------------------------------------------
[2019/06/01]::
+
Switched the `Position` structure to be bound to `Int64` and updated
the runtime system to use 64-bit integers for file offsets and
time values (in nanoseconds).  This change fixes bugs bugref:33[]
(Overflow exception with inputLine function) and bugref:36[] (Can't
open very large file).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/06/01]::
+
Added abstract `c_pointer` type to the primitive types.  This type
will be used to represent runtime-system pointers (__e.g.__, the
`HANDLE` values in the Windows implementation).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/31]::
+
Removed makefiles and code for architectures and operating systems
that are no longer supported (__e.g.__, the DEC Alpha and HPPA
architectures).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/31]::
+
Switched the `FixedInt` and `LargeWord` structure aliases to be 64-bits
(__i.e.__, `FixedInt` is now bound to `Int64` and `LargeWord` is bound
to `Word64`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/30]::
+
We are now assuming that we have at least **C99** support (for
practical purposes, this assumption is even true on Windows).
With this assumption, the allocation of small objects in the
runtime has been switched from macros to inline functions
(see `runtime/include/ml-objects.h`).  This change allows a
graceful handling of 32-bit integers, which are heap allocated
on 32-bit machines, but tagged on 64-bit machines.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/29]::
+
Fixed various bugs in the implementation of the `Word64` operations.
The addition and subtraction operators were using arithmetic right
shifts, instead of logical right shifts.  Also, the translation
of 64-bit shift operations was incorrect because of a typo in
the variable names.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/27]::
+
Created a simplified version of the `MLRiscGen` functor.  This version
of the functor, which is in the file `CodeGen/main/mlrisc-gen-fn.sml`
does not include the memory disambiguation and GC types code.  Since
the old version (`CodeGen/main/mlriscGen.sml`) did not use these
features by default, there should be no difference in the quality of
the generated code.
+
The purpose of this change is to remove unused code that has 32-bit
dependencies.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/25]::
+
Added contraction for unsigned `REM` and `NEG` operations in
`CPS/opt/contract-prim.sml`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.88; 2019/05/15

//--------------------------------------------------------------------
[2019/05/15]::
+
Moved the `compiler/DEVNOTES` directory to the `dev-notes` tree
and renamed it `old-compiler-notes`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/15]::
+
Added 64-bit versions of `NumFormat` and `NumScan`.  We use the 32-bit
version for numbers of 32-bits or less and the 64-bit versions for
numbers with up to 64 bits.  Thus, on 32-bit machines, the default
`int` and `word` types use `NumFormat32` and `NumScan32`, while on
64-bit machines they use `NumFormat64` and `NumScan64`.  This change
also required splitting out some common code into a `ScanUtil`
structure and also splitting out the scanning of real numbers into
the `ScanReal` structure (formatting of reals was already in its own
structure).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/15]::
+
Reimplemented the 64-bit `int` and `word` types to put them on a
(mostly) equal footing with the other precisions.  In this new implementation,
the basic types `int64` and `word64` are now `PRIMITIVE` (instead
of being `ABSTRACT` type represented by pairs of boxed 32-bit words).
Arithmetic and comparison operations on these types are represented as
primops and are preserved as such up to just before closure conversion.
At that point, the new `Num64Cnv` structure (`compiler/CPS/opt/numcnv.sml`)
is used to expand 64-bit operations and constants into 32-bit operations.
Most of the 64-bit primops are inline expanded, but multiplication and
division operations are converted to calls to library code from the
`CoreInt64` and `CoreWord64` modules (`system/smlnj/init`).
+
Because the type are primitive, we were able to change the runtime
representation to use packed records (`RK_RAWBLOCK`) to represent
them, which saves space and should also help with performance.
+
See the `dev-notes/num64.md` file for more details about the
implementation.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/09]::
+
Reorganized the Basis Library source files (`system/Basis`) to isolate
dependences on target word size.
+
In the `Basis/Implementation` directory, I created subdirectories
(__e.g.__, `Target32Bit`) to hold implementations that are specific
to the target.  These directories include a `bind-structs.sml` file
that replaces the many `bind-*.sml` files in `Basis/Implementation`.
+
In the `Basis/Exports` directory, I replaced the many individual
files (each with a single module renaming) with `bind-common.sml`
(for target-independent bindings) and a target-specific file
(either `bind-target-32-bit.sml` or `bind-target-64-bit.sml`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/05]::
+
Some of the CPS optimization modules (`Expand` and `EtaSplit` were
written as functors over the machine spec, when, in fact, they never
reference their functor argument.  Therefore, they have been converted
to structures.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/04]::
+
We now use the `InlineT.identity` primop for `Fn.id`, so the compiler
can optimize it.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/03]::
+
Fixed pretty-printing regression in 110.87; value of `char` type
were missing their enclosing quotes.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.87; 2019/05/03

//--------------------------------------------------------------------
[2019/05/03]::
+
Made the `Char.chr` operator inline (a primop was added to support
this change in 110.86).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/03]::
+
Major renaming of the primitive operators in the `Inline` structure
(as described in `dev-notes/primop-list.md`).  Also cleaned up the
**Basis Library** implementation to remove most (but not all)
32-bit dependencies.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/03]::
+
Added cases to the top-level pretty printer to handle the new basic
types that were added in 110.86 (*e.g.*, `word8vector` and `chararray`).
Also changed the way that primitive types are handled to use a
table keyed by tycons, instead of a sequence of nested conditionals.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.86; 2019/05/02

//--------------------------------------------------------------------
[2019/05/01]::
+
Added `word8vector` and `chararray` to the primitive types that
the compiler knows about.  These will be used in the rewriting
of the `InlineT` structure.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/01]::
+
Replaced the `Primop.primop` constructors `NUMSUBSCRIPT` and `NUMUPDATE`
with
+
````sml
| NUMSUBSCRIPT of numkind
| NUMSUBSCRIPTV of numkind
| NUMUPDATE of numkind
| INLNUMSUBSCRIPT of numkind
| INLNUMSUBSCRIPTV of numkind
| INLNUMUPDATE of numkind
````
+
This design matches the naming conventions for polymorphic subscripting
and updating.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/01]::
+
Added `Primop.INLCHR` to implement `Char.chr` as an inline function.
This change also required moving the definition of the `Chr`
exception to the `Core` module so that it is accessible to the
translate phase.  The inline version of Char.chr will be enabled
in the 110.87 release (we need the internal primop before we can
use it).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/05/01]::
+
Major overhaul of the representation of primitive operators (both in
the `Primop` and `CPS.P` structures).  The primitive arithmetic and
comparison operations are now defined in the `ArithOps` structure
(`ElabData/prim/arithops.sml`).  There are three datatypes defined
in this module
+
--
* arithop -- integer arithmetic operations that may raise overflow
* pureop -- arithmetic operations that are pure
* cmpop -- comparison operations
--
+
These types are used in both the `Primop` and `CPS.P` modules,
which makes the translation between representations more direct.
+
Some details:
+
--
* inline division and modulo operations were added to the
  `Primop.primop` datatype; the expansion of these in
  the `TransPrim` module (`FLINT/trans/transprim.sml`)
  adds explicit checks for division by zero.
* the `FSGN` operator was added to the `Primop.primop` datatype,
  since the new `cmpop` datatype does not include it (the
  CPS IR already had FSGN as a separate `branch` constructor).
* unsigned comparison operations are now represented by using
  the `UINT` `numkind`, which is consistent with how they
  are represented in `CPS`.
* Renamed the primop `ROUND` to `REAL_TO_ROUND`.
* the encodings for operators were revised in the pickler, resulting
  in a more compact use of the numeric codes.
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/28]::
+
Removed unused record kind constructors (`RK_SPILL`, `RK_EXN`, and
`RK_BLOCK`) from `CPS.record_kind` datatype.  Also renamed `RK_I32BLOCK`
to `RK_RAWBLOCK` and `RK_FBLOCK` to `RK_RAW64BLOCK`.  Various other
renamings to remove 32-bit assumptions.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/28]::
+
Renamed `DTAG_raw32` to `DTAG_raw`, since the semantics on 64-bit systems
will be to require word-size aligned raw data.  Also renamed `ML_AllocRaw32`
to `ML_AllocRaw` and `ML_ShrinkRaw32` to `ML_ShrinkRaw` for similar reasons.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/28]::
+
Removed unused flags from the `Control` structure; most of these came
from `Control.CG`, where roughly 20 out of 60 flags were no longer used.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/27]::
+
Split the contraction of primitive operators out of the `Contract`
structure into its own `ContractPrim` structure.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/27]::
+
Split the translation of primops to PLambda out into its own file
(`compiler/FLINT/trans/transprim.sml`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/27]::
+
Fixed regression: `Word32.toInt 0wx8002DE32;` would return `187954` instead
of raising `Overflow`.  The problem was a mistake in the way that the overflow
trap was being generated in `MLRiscGen`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/26]::
+
Some minor primop cleanup.
+
--
* Changed the types of `Primop.ROUND` and `Primop.REAL`
  to take bitwidths, instead of numkinds, since the kinds are always the same.
  Also, the fields are now called `from` and `to` (instead of `fromkind` and
  `tokind`) to be consistent with other conversion primops.
* Renamed `ABS` to `FABS`, since it is only used on floating-point numbers.
* Renamed the CPS primitive operator `ROUND` to `REAL_TO_INT` and the operator
  `REAL` to `INT_TO_REAL`.
* Renamed the `Primop.REAL` to `Primop.INT_TO_REAL` so that it is not confused
  with the other constructors named `REAL`.
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/23]::
+
Improvements to the core 64-bit int and word modules in `system/smlnj/init`.
Replaced `Int64.+`, `Int64.-`, `Word64.+`, and `Word64.*` with versions
from *Hacker's Delight* that use fewer conditional branches.  Also
replaced the relational operators (`<`, `<=`, etc) with more direct
implementations.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/21]::
+
Fix for bug bugref:213[] (`Int32.div` raises `Div` instead of `Overflow`
when dividing `minInt` by `~1`).  Since the compiler generates an
explicit test for division by zero, we know that the only arithmetic
traps must be caused by other operations.  Therefore, we can just
map any arithmetic trap to `Overflow`.
+
Also removed the old SPARC assembly code for multiplication and
division.  The code generator always uses the native hardware
instructions, so the assembly code is not needed.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/21]::
+
Yet another attempt to get the implementation of `use` in the REPL
working in a sensible way.
+
With these changes, `use` should behave as follows.
If an invocation of `use` encounters
a compilation error (either in the initial file or in a nested
invocation of `use`), then the compiler error message will be
printed and the call to `use` will immediately return `()`.
If an invocation of `use` raises an exception during execution
of the compiled code (either in the initial file or in a nested
invocation of `use`), then the exception will be reported at
the top-level.  Any change to the global state or environment
that occurs before an error is encountered, will **not** be rolled
back.
+
Files specified as command-line arguments to the **sml** command
will be treated as if `use` was invoked on them.  If there is an
error, then the error will be reported and the **sml** command
will terminate with a non-zero exit status (at least on Unix).
+
This change fixes bugs bugref:193[], bugref:217[], and bugref:219[].
There is a connection between this change and bugref:183[], which
was fixed in Version 110.82.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/21]::
+
Change to the CPS primops: moved the `F_SGN` operator (which is unary)
from the `fcmp` datatype to the `branch` datatype (and renamed it `FSGN`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/21]::
+
Finished conversion of the CPS IR to a form that is compatible with
ASDL.  Basically, this involved converting the datatype constructor
names to upper-case identifiers.
+
These changes are a step in the plan to eventually switch to an LLVM-based
code generator that will be given pickled CPS code as its input.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/08]::
+
Starting to migrate the CPS IR toward the ASDL version.  Changed the
names of the `CPS.P.arith` and `CPS.P.cmpop` constructors to be upper-case
alpha IDs (many of them were symbolic identifiers).  Also split out the
various utility functions into the new `CPSUtil` module (`CPS/cps/cps-util.sml`).
Lastly, moved the `literals.sml` file from `FLINT/main` to `CPS/main` (where
it belongs).
+
Note that the `CPS.P.arithop` datatype is now identical to the `Primop.arithop`
datatype
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2019/04/07]::
+
Reorganized the backend of the compiler by moving the CPS-related
code into its own directory tree (`Compiler/CPS`) and replacing the
`FLINTComp` functor with the `FLINTOpt` structure and the `CPSCompFn`
functor.  The conversion from FLINT to CPS is part of the `CPSCompFn`
functor, which takes the program representation all the way from
FLINT to machine code segments.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.85; 2018/12/21

//--------------------------------------------------------------------
[2018/12/21]::
+
Modified `config/install.sh` to look for a pre-Mojave SDK when trying
to install on macOS 10.14 Mojave.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/12/21]::
+
Updated `runtime/objs/cygwin.def` so that the runtime system will build
on 32-bit Cygwin.  Also updated installation script to suggest using
the 32-bit version of Cygwin when a user tries to install it on Cygwin64.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/11/10]::
+
**Xcode** 10.1, which is Apple's development environment for **macOS 10.14
Mojave**, does not include the libraries needed to build 32-bit executables,
such as the SML/NJ runtime, although 32-bit programs will still run.
+
To support building on Mojave, I added a new Makefile (`mk.x86-darwin18`)
for the runtime system and modified the `config/install.sh`
script to use this makefile when necessary.  This new makefile expects
that the `MacOSX10.13.sdk` directory from **Xcode** 9 has been
copied into the **Xcode** 10 SDKs directory.  Note that updating **Xcode**
from the AppStore will likely remove the 10.13 SDK, so you should keep
a copy in a safe place.
+
The **Xcode** SDKs live in `Platforms/MacOSX.platform/Developer/SDKs`
under the `Developer` directory.  One can determine the path to the
current developer directory using the command
+
[source,shell]
--------------
% xcode-select -p
--------------
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/10/10]::
+
Removed several unsupported primitive operators from the compiler.
In the CPS IR, these were `free`, `acclink`, `setpseudo`, `setmark`, and
`getpseudo`.  The pseudo-register operations were not supported in the
code generator, while the others were no-ops.  The corresponding
operators `GETPSEUDO`, `SETPSEUDO`, `SETMARK`, and `DISPOSE` were removed
from `ElabData/prim/primop.sml` and their bindings were removed from
`Semant/prim/primop-bindings.sml` and the `InlineT` and `Unsafe`
structures.
+
The `AllocProf` module in the compiler was also disabled, since it
relied on the pseudo registers for recording profile information at
runtime.  Furthermore, uses of the `acclink` primitive operation in
`FLINT/cps/closure.sml` when static profiling is enabled were removed.
+
These changes were committed as revision 4886.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/10/08]::
+
Fix for bug bugref:216[] (run-time system fatal error with large top-level
value).  The problem was in the code for building literals.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/09/23]::
+
Change CPS operators for wrapping/unwrapping integer and float values to
be word-size flexible.  We now use a single `wrap` (and `unwrap`) operator
that is parameterized by a `numkind` value.  We also changed the `wrap`/`unwrap`
operators to `box`/`unbox`.  The mapping from old operators to new ones
is as follows:
+
[%autowidth,cols=">10,^1,<25"]
|===

| `wrap`	| =>	| `box`

| `unwrap`	| =>	| `unbox`

| `iwrap`	| =>	| `wrap(INT defaultIntSz)`

| `iunwrap`	| =>	| `unwrap(INT defaultIntSz)`

| `i32wrap`	| =>	| `wrap(INT 32)`

| `i32unwrap`	| =>	| `unwrap(INT 32)`

| `fwrap`	| =>	| `wrap(FLOAT 64)`

| `funwrap`	| =>	| `unwrap(FLOAT 64)`

|===
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/09/13]::
+
Further cleanup for 64BIT in function `atomeq` in `PEqual`.
(`base/compiler/FLINT/trans/pequal.sml`).
Added `numKind`, `intEqTy`, and `uintEqTy` functions.
The `numKind` function should be extended once `int64` and `word64` are treated as primitive
types in the compiler.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2018/09/12]::
+
Fixed 64BIT issue in module `MatchComp`
(`base/compiler/FLINT/trans/matchcomp.sml`).
Added `int64Ty` and `word64Ty` cases to function `numCon`.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2018/09/12]::
+
Fixed 64BIT issue in module `Equal`
(`base/compiler/FLINT/reps/equal.sml`).
Exports just one function: `equal_branch`, which is called once in
`reps/wrapping.sml` to type-specialize branches on calls to `POLYEQUAL`.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2018/09/12]::
+
The CPS optimizer had a mechanism for checking the CPS against the FLINT
types, which required maintaining a mapping from lvars to their FLINT
types.  This code has long since bit-rotted and cannot even handle a
simple expression like `1+2`.  Therefore, I've removed the mapping (a hash
table) from the CPS optimizer and the vestigial code that modified it
in the various CPS optimization passes.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/09/12]::
+
Modified the `InfCnv` (now named `IntInfCnv`) structure to remove
32-bit dependencies.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/09/11]::
+
Modified `Pequal` (in `base/compiler/FLINT/trans/pequal.sml`) and
`Translate` (in `base/compiler/FLINT/trans/translate.sml`) to remove
32-bit dependencies. though further changes will be required to
properly handle `int64` and `word64` types when `defaultIntSz` = 64.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2018/09/11]::
+
Reimplemented the `Switch` module (int `base/compiler/FLINT/cps`).  The
new implementation follows the same basic design as before, but the code
is better organized and documented, and it now uses the concrete `CPS`
representations, instead of being parameterized over an abstraction of
them.  It also now uses binary search for boxed (e.g., `Int32.int`)
switches.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.84; 2018/09/03

//--------------------------------------------------------------------
[2018/09/03]::
+
Reimplemented the array/vector-slice modules to use a (base, start, length)
representation (as does Substring in system/smlnj/init/substring.sml).  Also
fixed a bug in the slice findi functions, where the index being passed to the
predicate function was not adjusted to be slice-relative.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/09/02]::
+
Implemented https://github.com/SMLFamily/BasisLibrary/wiki/2018-002-Additional-slice-operations[
Basis Library proposal 2018-002 (Additional slice operations)].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/09/02]::
+
Improved implementation of `CharVectorSlice.map` and `CharVectorSlice.mapi`
to not build intermediate list of results.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/08/28]::
+
A beta-release of ASDL library and *asdlgen* tool have been added to
the system.  This version of the tool implements SML support, but the
C++ support is not complete.  There is a CM tool for ASDL, which
recognizes the `.asdl` file suffix.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/08/28]::
+
Two changes to the installer (`base/base/system/smlnj/installer`):
+
--
1. The build scripts for programs are now named `build.sh` (instead of
   `build`) on Unix systems.
2. The *config* action has been added to support module configuration.
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/08/27]::
+
Added `RENAME` extension style to CM tool support.  This extension
style allows arbitrary file names to be generated from the base name.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/08/19]::
+
Fixed a bug in the implementation of monomorphic buffers: the functions
`CharBuffer.add1` and `Word8Buffer.add1` had an incorrect length
test.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/06/15]::
+
Fixed a compiler bug (`arg ty lists wrong length`) in `unifyTy` that
could occur when one of the type constructors is the `ERRORtyc`.
This bug occurs because the `ERRORtyc` is equal to any other type
constructor, which (incorrectly) implies that the number of type
arguments should be equal.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.83; 2018/06/01

//--------------------------------------------------------------------
[2018/05/29]::
+
Fixed bugref:206[] (Parsing of explicit type variables and val rec
is broken).  This bug was also bug number 1261 in the old bugs list.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/29]::
+
Fixed minor bug in Date.toString (missing leading "0" for day of month).
This issue was bug number 1444 in the old bugs list.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/29]::
+
Cleaned up match compiler code (`FLINT/trans/matchcomp.sml`) and added
typing and function comments.  Added debugging and printing
infrastructure, including new `FLINT/trans/mcprint.sml` file, and new
`Control.MC.debugging` flag.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2018/05/29]::
+
Fixed parser to allow parentheses around `val rec` patterns.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/28]::
+
Fixed the scanner to produce the correct error message for bad escape
sequences in string literals.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/26]::
+
Fixed old bug number 1383: `Char.toCString #"\000"` returned `"\\0"`,
instead of `"\\000"`, which caused `String.toCString` to produce invalid
results.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/19]::
+
Fix for bug bugref:201[] (The AMD64.cm library is missing).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/18]::
+
Added `MONO_BUFFER` signature, with instances `CharBuffer` and `Word8Buffer`,
to Basis implementation
(https://github.com/SMLFamily/BasisLibrary/wiki/2018-001-Addition-of-monomorphic-buffers[
Basis Library Proposal 2018-001]).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/16]::
+
Fix a bug where "`0w`" was being accepted as a prefix for a hexidecimal
word value in `Word.fromString`/`scan` (ignoring case, only "`0x`"
and "`0wx`" are valid prefixes).  This change fixes bug number 1375
from the old bugs list.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/13]::
+
Fixed a bug in the parsing of bindings involving the `op` keyword.
The parser was more restrictive than the definition.  This change
fixes bug number 1370 from the old bugs list.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/12]::
+
The lexer gave an unmatched close comment error on "++*)++", when it
should have scanned it as the tokens "++*++" "++)++".  This change
fixes bug number 330 in the old bugs list.
+
**Note**: there is some ambiguity as to what the correct behavior
should be here.  The __Definition of Standard ML__ (1997) only says that
unmatched __open__ comments should be signalled as errors, but the
__Commentary on the Definition of Standard ML__ (1991) says otherwise in
Appendix D.  **SML/NJ** started signalling an error in version 0.71,
but we choose to revert to accepting this sequence, to match
the 1997 Definition (and the behavior of other systems).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/07]::
+
The `sameSign` function returned incorrect results in the `Int31`
and `Int32` modules.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/07]::
+
Fixed various minor parsing and scanning issues:
+
--
* correct syntax for type variables
* signature/structure/functor IDs should always be alpha IDs
* the equality ID (`=`) cannot appear in a binding context.  Note that
  we still allow the syntax `val op = = ...` because it is needed to
  parse the file `system/smlnj/init/built-in.sml`.
--
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/05/05]::
+
Completed overhaul of the way that int/word literals are handled in
the compiler.  We now use `IntInf.int` to represent the values in
all IRs.  This change also results in better CPS contraction, since
we now perform constant folding for both signed and unsigned values
at all sizes.  We were also able to get rid of the tricky code that
worries about large tagged integer values that might cause overflow
during code generation.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/04/21]::
+
Improved the reporting of errors involving literal values.  We now
use the original source text when describing the value in the error
message.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/04/20]::
+
Fix for bug bugref:191[] (Compiler crash when handling large reals).
We now issue a warning for real literals that will round to zero and
an error for real literals that are too large to represent.  There
still needs to be done some work to support sub-normal literal values
(these are currently rounded to zero).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/04/14]::
+
Changed the representation of real literals from strings to `RealLit.t`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/04/13]::
+
Removed real patterns from Absyn and FLINT, since they are not allowed
by SML'93 and were not present in the AST representation.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2018/04/12]::
+
Fix for bug bugref:194[] (`Real.fromString` overflows or hangs).  There
were two issues here.  First, the `Overflow` exception was being raised
when scanning large exponents, but it was not being handled by the
scanning code.  The second issue was that the scaling loop for large
exponents did not immediately terminate once infinity (or zero) was
reached, so it could take a long time.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/10/22]::
+
Moved the Version-1 literal building code into `gc/old-literals.c`.
This file can be removed once the compiler generates the Version-2
literal bytecode.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/10/16]::
+
Moved the check for whether a int or word literal is in range for
its type from the absyn->plambda translation to the overload
resolver (`compiler/Elaborator/types/overload.sml`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/10/14]::
+
Part 1 of an overhaul of the way that the compiler treats int/word
literals.  The end goal is to use `IntInf.int` to represent literals
throughout all phases of the compiler.  In this step, we changed the
representation of literals in the `Absyn` representation (earlier
representations already used IntInf.int).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.82; 2017/10/16

//--------------------------------------------------------------------
[2017/10/01]::
+
Fixed unnumbered bug in `IntInf.mod` and `IntInf.rem` functions,
where the `Div` exception was *not* getting raised when both
arguments are `0`.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/09/20]::
+
Various bits of cleanup in the handling of primitive operations, such
as removing the `ptnum` mechanism for translating from Absyn to FLINT.
+
owner:cs.uchicago.edu/~dbm[David MacQueen]

//--------------------------------------------------------------------
[2017/09/20]::
+
Added `Target` module, which specifies the properties of the target
(__e.g.__, the size in bits of the default int type).  Reworked the
generation of the `InlineT` structure to be target specific.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/09/18]::
+
Removed FLINT primops (and their CPS counterparts) that are not
in the `InlineT` structure and, thus, are never used by the compiler.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/09/18]::
+
Fixed bug bugref:123[] (missing nonexhaustive bind warning). The `mkVBs`
function in `FLINT/trans/translate.sml` was adding a redundant default
rule by calling `ElabUtil.completeMatch` after a default rule had
already been explicitly added to the match for let bindings.
+
owner:cs.uchicago.edu/~dbm[David MacQueen]

//--------------------------------------------------------------------
[2017/09/18]::
+
Fixed bug bugref:183[] (status code returned by sml REPL).  This fix
restores the version 110.79 behavior of having `sml foo.sml` exit with
a non-zero status when there is a type-checking error in `foo.sml`.
It also cleans up the error messages associated with `use` when there
is a syntax error.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/08/28]::
+
Fixed bug bugref:185[] (Bring command line help text into parity with man page).
Added missing options (`@SMLversion` and `@SMLsuffix`) to the
help message that is printed for the command "`sml -h`".  Also
adjusted the order of options in the help message, and in the man
page, so that the orders match.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/08/12]::
+
Changed the way that we test for allocation-space addresses in minor GCs.
Instead of using the BIBOP, we now do a pointer range test.  On 32-bit
systems, this change results in a small (~0.13%) performance boost, but
we expect a bigger impact on 64-bit hardware, where the cost of BIBOP
probes will be higher and there are more registers available to hold
the nursery bounds.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/08/12]::
+
Fixed some issues in build-literals.c.  These were mostly false
positives in the assertions, but there was also a bug in the way
that the available space was tracked that could conceivably
result in a crash (but was very unlikely).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/06/07]::
+
Updated _arch-n-os script to recognize macOS 10.13 (High Sierra)
as a valid target.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/05/17]::
+
Fixed a bug in the way that JSON string values were being printed.
The code previously assumed that C-style escaping will work, but
that is not true for "\'" (as well as for control and non-ASCII
characters).  The new implementation assumes that the string value
is UTF-8 and uses the "\\u" escape sequences for characters outside
the JSON escapes and printable ASCII characters.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.81; 2017/05/01

//--------------------------------------------------------------------
[2017/04/28]::
+
Fixed bug bugref:129[] (Symbolic identifiers are allowed as strids).
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2017/04/07]::
+
Fixed bug bugref:179[] (ml-ulex writing debug messages to stdOut).
Both **ml-ulex** and **ml-antlr** now direct their debug and status messages
to `stdErr` (instead of `stdOut`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2017/02/09]::
+
Linux distributions are starting to require that the stack be marked
as non-executable in applications.  Because the runtime system includes
assembly code, this marking was not happening.  We've added `.section`
directives to the `PPC.prim.asm` and `X86.prim.asm` files as
per https://wiki.gentoo.org/wiki/Hardened/GNU_stack_quickstart#Patching[].
Thanks to Daniel Moerner for reporting this issue and for providing
a pointer to the fix.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/10/15]::
+
Added `--debug` command-line option to *ml-antlr*.
This flag causes <b>ml-antlr</b> to generate debug actions that print
the left-hand-side non-terminal of the production.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/09/15]::
+
Working on 64-bit support.  Changes include making code generation
dependent on the target word size and abstracting over the BIBOP
representation in the runtime system.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/09/15]::
+
Further cleanup of the separation of FLINT from the front-end.
Eliminated all references to `ModulePropLists` (`module-plists.sml`) in
the front end and in pickling, and moved `module-plists` from
`Semant/modules` to `FLINT/trans`.  `ModulePropLists` is now only used
in `FLINT/trans/translate.sml`.
+
Revision: 4314
+
Files changed:
+
--
- `compiler/ElabData/modules/modules.sml`  (cleaned up)
- `compiler/Elaborator/print/ppmod.sml` (cleaned up)
- `compiler/FLINT/trans/module-plists.sml` (moved from `Semant/modules`)
- `compiler/Semant/modules/instantiate-param.sml` (deleted)
- `compiler/Semant/pickle/pickmod.sml` (no longer mentions property lists)
- `compiler/Semant/pickle/unpickmod.sml` (ditto)
- `compiler/Semant/statenv/prim.sml`
- `compiler/Semant/types/tp-var-info.sml`  (deleted)
- `compiler/core.cm`  (modified for move of `module-plists.sml`)
--
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2016/09/14]::
+
Eliminated dependency of `PlambdaType` from the front end by adding a
type `TKind.tkind` which is a simplified standin for `PlambdaType.tkind`
for use during elaboration. `TKind.tkind` values are translated on
demand to `PlambdaType.tkind` in `trans/transtypes.sml`. Types still has
a `tycpath` type but it is defined using `TKind.tkind` now. The new structure
`SigPropList` replaces `ModulePropLists`
(`Semant/modules/module-plists.sml`) for use in `instantiate.sml`.
`Instantiate` is now defined directly as a structure so the functor
application in `Semant/modules/instantiate.sml` no longer exists.
+
Files changed:
+
--
- `ElabData/basics/debindex.sig`  (moved here from `Elaborator/basics`)
- `ElabData/basics/debindex.sml`  (ditto)
- `ElabData/basics/sig-plist.sml` (new)
- `ElabData/basics/tkind.sml`     (new)
- `ElabData/types/types.sig`
- `ElabData/types/types.sml`
- `Elaborator/modules/instantiate.sml`
- `Elaborator/print/ppmod.sml`
- `FLINT/trans/transtkind.sml`    (new)
- `FLINT/trans/transtypes.sml`
- `TopLevel/interact/evalloop.sml`
- `ElabData/elabdata.cm`
- `Elaborator/elaborate.cm`
- `core.cm`
--
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2016/09/14]::
+
Added support for Successor ML record-expression-punning syntax.  For
example, one can now define a function `f` as
+
[source,sml]
----------------
fun f x = {x}
----------------
+
which is equivalent to the definition
+
[source,sml]
----------------
fun f x = {x = x}
----------------
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/09/14]::
+
Fixed a bug in the parser.  Asterix (`*`) was not allowed as a record label
when using the record-pattern-punning syntax.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/09/14]::
+
Added support for `do exp` *Successor ML* syntax.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/09/12]::
+
Fixed bug bugref:153[] (Enabling Successor ML features is delayed).
We now use a function `Control.setSuccML` to switch to/from *Successor ML*
mode in the REPL. The function resets the parser, so the next input will
be correctly parsed.  The `Control.succML` flag is no longer visibile
in the REPL.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/09/12]::
+
Fixed bug bugref:149[] (Datatype replication exposes hidden constructors).
Added boolean field `stripped` to DATATYPE variant of tyckind in
`compiler/ElabData/types/types.sml` with default value `false`.
`stripped` is set to true when a datatype is matched with a simple
`type` spec in signature matching, and datatypes with `stripped` set
to true are disallowed in datatype replications.
+
Files changed:
+
--
- `compiler/ElabData/types/types.sig`
- `compiler/ElabData/types/types.sml`
- `compiler/ElabData/types/typesutil.sml`
- `compiler/ElabData/types/core-basictypes.sml`
- `compiler/Elaborator/types/basictypes.sml`
- `compiler/Elaborator/types/eqtypes.sml`
- `compiler/Elaborator/modules/evalent.sml`
- `compiler/Elaborator/modules/sigmatch.sml`
- `compiler/Elaborator/modules/instantiate.sml`
- `compiler/Elaborator/print/ppabsyn.sml`
- `compiler/Elaborator/print/pptype.sml`
- `compiler/Elaborator/elaborate/elabcore.sml`
- `compiler/Elaborator/elaborate/elabmod.sml`
- `compiler/Elaborator/elaborate/elabtype.sml`
- `compiler/Elaborator/elaborate/elabsig.sml`
- `compiler/Semant/pickle/pickmod.sml`
- `compiler/Semant/pickle/unpickmod.sml`
- `compiler/MiscUtil/print/ppobj.sml`
- `compiler/FLINT/trans/transtypes.sml`
- `compiler/FLINT/trans/pequal.sml`
--
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2016/08/31]::
+
Added `%tokentype` directive to *ml-antlr*; this directive allows users
to specify the token datatype externally, which is necessary in order
to share a lexer with two different *ml-antlr* parsers.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/08/20]::
+
Change the interface to `AMD64Gen` in *MLRISC*; the `signBit` and
`negateSignBit` callbacks now return an `MLTree.rexp` (instead of a
label).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.80; 2016/08/19

//--------------------------------------------------------------------
[2016/08/16]::
+
Fixed bugref:151[] (Error installing from source on Mac OS X).  The fix
involves both changes to the `config/install.sh` script and the
`mk.x86-darwin` makefile.  With this fix, we include the `SDK` argument
to the `/usr/bin/as` only when the OS version is 10.10 (Yosemite) or
later.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/08/10]::
+
Added the proposed `unzipMap`, `unzipMapi`, `find`, and `findi` functions
to the `ListPair` module.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/08/10]::
+
Added the proposed `mapLeft`, `mapRight`, `appLeft`, and `appRight`
functions to the `Either` module.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/08/09]::
+
Fixed bug bugref:145[] (Internal exception occurs on bogus annotation
instead of typechecking diagnostic). Added missing `OVLD_UB` case in
function `failMessage` in `compiler/Elaborator/types/unify.sml`.
+
owner:cs.uchicago.edu/~dbm[Dave MacQueen]

//--------------------------------------------------------------------
[2016/08/04]::
+
Fixed bug bugref:166[] (Can't install SML/NJ in directories containing
spaces).  Thanks to Eugene Sharygin for the patch.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/06/21]::
+
Fixed incorrect dividend sign extension before 32-bit divide in amd64
code generator in MLRISC
+
owner:gallium.inria.fr/~rainey/[Mike Rainey]

//--------------------------------------------------------------------
[2016/06/16]::
+
Fixed bug bugref:150[] (Add title to batch script).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/05/11]::
+
Implemented the changes for
https://github.com/SMLFamily/BasisLibrary/wiki/2016-001-Add-popCount-to-WORD-signature[
Basis Library Proposal 2016-001].  This proposal added the `popCount`
function to the `WORD` signature.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/05/03]::
+
Fixed bug bugref:156[] (sml resumes after SIGSTOP with bogus exception
report).  The fix is a bit of a hack: I modified the `non_bt_hdl`
function in `evalloop.sml` to match an `IO.Io` exception with
the appropriate shape for this situation.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/04/07]::
+
Fixed bug bugref:154[] (Return code for ml-ulex when there is an error).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/04/07]::
+
Fixed bug bugref:155[] (Misleading printing of word literals in
error messages).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2016/04/02]::
+
Fixed a bug in the implementation of the `--ml-lex-mode` flag for
*ml-ulex*.  The `\h` escape sequence is supposed to map to the
character range `[\128-\255]`, but did not.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/11/09]::
+
Fixed bug bugref:147[] (Hexadecimal escapes in strings are not supported).
We previously did not support Unicode escapes in string literals.  We now
do so, [line-through]#with non-ascii codepoints being mapped to the
UTF-8 encoding# with escape values in the range 0..255 being mapped to the
corresponding 8-bit character.  Values outside that range are flagged
as an error.
+
_Revised August 4, 2016_
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/10/28]::
+
Partial fix for the noisy exception-stack traces on the `Error` exception.
The cases that are handled by this change are applying `use` to a non-existent
file and when there are compilation errors in a program being built by
`CM.make`.  What remains to be handled is the situation where `CM.make` is
applied to a non-existent file.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//====================================================================
== Version 110.79; 2015/10/04

//--------------------------------------------------------------------
[2015/10/04]::
+
Patched `base/compiler/FLINT/clos/closure.sml` so that *Twelf* will
build again.  Fixes bug bugref:140[] (Lookup failure in `closure.sml`
when compiling *Twelf*).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/09/28]::
+
Added support for a *Successor ML* tool to CM.  This tool allows one
to specify that a source file `fool.sml` is *Successor ML* source code in the
following ways:
+
--------
foo.sml : succ-ml
foo.sml : sml (succ-ml)
foo.sml (succ-ml)
--------
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/09/28]::
+
Added the directory `base/old-basis` to support backward-compatible
views of the *Basis Library*.  You can use these by replacing the
line
+
--------
$/basis.cm
--------
+
with
+
--------
$/basis-2004.cm
--------
+
in your CM files.

//--------------------------------------------------------------------
[2015/09/28]::
+
New implementation of `Date` structure in the Basis, which fixes bugs
bugref:138[] (Incorrect behavior for `Date.fromTimeLocal`) and
bugref:139[] (`Date.date` is broken).  Note that some more thought should
be given to the correct semantics of `Date.date` when dealing with
offsets.  For example, should an offset of +23 hours produce the same
date as an offset of -1 hours?  Currently our implementation produces
different results (by a day) for these two situations.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/09/25]::
+
Implemented the changes for
https://github.com/SMLFamily/BasisLibrary/wiki/2015-003-Additional-operations-on-sequences[
Basis Library Proposal 2015-003].  This proposal added operations to
the following signatures:
+
[source,sml]
------------
signature ARRAY
signature LIST
signature LIST_PAIR
signature MONO_ARRAY
signature MONO_VECTOR
signature OPTION
signature STRING
signature TEXT
signature VECTOR
------------
+
and the following structures:
+
[source,sml]
------------
structure Array : ARRAY
structure CharArray : MONO_ARRAY
structure CharVector : MONO_VECTOR
structure List : LIST
structure ListPair : LIST_PAIR
structure Option : OPTION
structure Real64Array : MONO_ARRAY
structure Real64Vector : MONO_VECTOR
structure String : STRING
structure Text : TEXT
structure Vector : VECTOR
structure Word8Array : MONO_ARRAY
structure Word8Vector : MONO_VECTOR
------------
+
While it is very unlikely that these changes will break existing code, there are
a a couple scenarios in which the code might break.  Namely, when use of `open`
introduces conflicts and when user code implements one of the affected Basis Library
signatures.  Both of these examples occurred in the *SML/NJ* source code; the former
in the *ml-yacc* sources and the latter in the *MLRISC* sources.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/09/25]::
+
Added the optional implementations of `PackReal64Big` and `PackReal64Little`.
This addition addresses feature request bugref:82[feature]
(Implementations of `PACK_REAL` missing).  The implementation
uses the approach suggested by
https://github.com/msullivan/sml-util/blob/master/libs/pack-real.sml[Michael Sullivan].
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/09/24]::
+
Fixed bug bugref:45[] (Compiler bug in specialize phase).  This bug
was in `compiler/FLINT/opt/fcontract.sml` and was the result of a bad
interaction between eta contraction and inlining.  As part of the fix,
I cleaned up the code in this part of FLINT a bit.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/09/21]::
Improvements to the error messages produced by the *ml-ulex* lexer generator.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/09/21]::
Added `Ref` structure and `REF` signature to Basis implementation
(https://github.com/SMLFamily/BasisLibrary/wiki/2015-007-Addition-of-Ref-module[
Basis Library Proposal 2015-007]).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/09/21]::
Added `Fn` structure and `FN` signature to Basis implementation
(https://github.com/SMLFamily/BasisLibrary/wiki/2015-005-Addition-of-Fn-module[
Basis Library Proposal 2015-005]).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/08/22]::
+
Fixed bug bugref:136[] (Incorrect raising of exceptions in `Real.fmt`
and `Time.fmt`).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/08/14]::
+
Added `Either` structure and `EITHER` signature to Basis implementation
(https://github.com/SMLFamily/BasisLibrary/wiki/2015-002-Addition-of-Either-module[
Basis Library Proposal 2015-002]).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/07/23]::
+
Fixed bug bugref:135[] (Fails to build on Linux PowerPC).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/07/08]::
+
Added Linux 4.* kernels to the list of operating systems recognized
by the `.arch-n-opsys` script (fixes bug bugref:134[]).
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/06/11]::
+
Added Mac OS X 10.11 (El Capitan) to the list of operating systems
recognized by the `.arch-n-opsys` script.
+
owner:cs.uchicago.edu/~jhr[John Reppy]

//--------------------------------------------------------------------
[2015/05/27]::
+
Added support for *Successor ML* lexical extensions.  These can be enabled
using the command-line option `-Cparser.succ-ml=true` or by the assignment
+
[source,sml]
------------
Control.succML := true;
------------
+
at the REPL.  The extensions are as follows:
+
--
  - Underscore ("`_`") as a separator in numeric literals; __e.g.__, `123_456`,
    `0wxff_ff_ff_f3`, `123_456.1`, ...

  - end-of-line comments, which are denoted using `(*)`.  End-of-line comments
    properly nest into conventional block comments.  For example, the following
    block comment is well formed:
+
[source,sml]
------------
(*
fun f x = x (*) my identity function *)
*)
------------
+
  - binary literals for both integers and words; __e.g.__, `0b0101_1110`, or
    `0wb1101`.
--
+
This change is the beginning of a program to add *Successor ML* feature to *SML/NJ*;
See https://github.com/SMLFamily/Proposed-Definition-of-Successor-ML[] for more
details.
+
owner:cs.uchicago.edu/~jhr[John Reppy]
