This is the HISTORY file for the Yale SML/NJ CVS repository.

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.

The form of an entry should be:

Name: 
Date:
Tag: <post-commit CVS tag>
Description:

----------------------------------------------------------------------
Name: Matthias Blume
Date: 2000/03/31 18:00:00 JST
Tag: blume_main_v110p26p2_1
Description:

This update contains:

1. A small change to CM's handling of stable libraries:
   CM now maintains one "global" modmap that is used for all stable
   libraries.  The use of such a global modmap maximizes sharing and
   minimizes the need for re-traversing parts of environments during
   modmap construction.  (However, this has minor impact since modmap
   construction seems to account for just one percent or less of total
   compile time.)

2. I added a "genmap" phase to the statistics.  This is where I got the
   "one percent" number (see above).

3. CM's new tool parameter mechanism just became _even_ better. :)
   - The parser understands named parameters and recursive options.
   - The "make" and "shell" tools use these new features.
     (This makes it a lot easier to cascade these tools.)
   - There is a small syntax change: named parameters use a

       <name> : ( <option> ... )            or
       <name> : <string>

     syntax.  Previously, named parameters were implemented in an
     ad-hoc fashion by each tool individually (by parsing strings)
     and had the form

       <name>=<string>

   See the CM manual for a full description of these issues.

----------------------------------------------------------------------
Name: Matthias Blume
Date: 2000/03/30 18:00:00 JST
Tag: blume_main_v110p26p2_0
Description:

!!!!! WARNING !!!!!!
!!  New binfiles  !!
!!!!!!!!!!!!!!!!!!!!

This update contains:

1. Moderate changes to CM:

   - Changes to CM's tools mechanism.  In particular, it is now possible
   to have tools that accept additional "command line" parameters
   (specified in the .cm file at each instance where the tool's class is
   used).

   This was done to accomodate the new "make" and "shell" tools which
   facilitate fairly seemless hookup to portions of code managed using
   Makefiles or Shell scripts.

   There are no classes "shared" or "private" anymore.  Instead, the
   sharing annotation is now a parameter to the "sml" class.

   There is a bit of generic machinery for implementing one's own
   tools that accept command-line parameters.  However, I am not yet fully
   satisfied with that part, so expect changes here in the future.

   All existing tools are described in the CM manual.

   - Slightly better error handling.  (CM now surpresses many followup
   error messages that tended to be more annoying than helpful.)

2. Major changes to the compiler's static environment data structures.

   - no CMStaticEnv anymore.
        - no CMEnv, no "BareEnvironment" (actually, _only_ BareEnvironment,
          but it is called Environment), no conversions between different
          kinds of static environments

   - There is still a notion of a "modmap", but such modmaps are generated
     on demand at the time when they are needed.  This sounds slow, but I
     sped up the code that generates modmaps enough for this not to lead to
     a slowdown of the compiler (at least I didn't detect any).

   - To facilitate rapid modmap generation, static environments now
     contain an (optional) "modtree" structure.  Modtree annotations are
     constructed by the unpickler during unpickling.  (This means that
     the elaborator does not have to worry about modtrees at all.)
     Modtrees have the advantage that they are compositional in the same
     way as the environment data structure itself is compositional.
     As a result, modtrees never hang on to parts of an environment that
     has already been rendered "stale" by filtering or rebinding.

   - I went through many, many trials and errors before arriving at the
     current solution.  (The initial idea of "linkpaths" did not work.)
     But the result of all this is that I have touched a lot of files that
     depend on the "modules" and "types" data structures (most of the
     elaborator). There were a lot of changes during my "linkpath" trials
     that could have been reverted to their original state but weren't.
     Please, don't be too harsh on me for messing with this code a bit more
     than what was strictly necessary...  (I _did_ resist the tempation
     of doing any "global reformatting" to avoid an untimely death at
     Dave's hands. :)

   - One positive aspect of the previous point:  At least I made sure that
     all files that I touched now compile without warnings (other than
     "polyEqual").

   - compiler now tends to run "leaner" (i.e., ties up less memory in
     redundant modmaps)

----------------------------------------------------------------------
Name: Allen Leung
Date: 2000/03/29 18:00:00
Tag: leunga-20000327-mlriscGen_hppa_alpha_x86
Boot files (optional): ftp://react-ilp.cs.nyu.edu/leunga/110.26.1-sml.boot.x86-unix-20000330.tar.gz
Description:
 
   This update contains *MAJOR* changes to the way code is generated from CPS
in the module mlriscGen, and in various backend modules.

CHANGES
=======

1. MLRiscGen: forward propagation fix.

   There was a bug in forward propagation introduced at about the same time
   as the MLRISC x86 backend, which prohibits coalescing to be 
   performed effectively in loops. 

   Effect: speed up of loops in RISC architectures.
           By itself, this actually slowed down certain benchmarks on the x86.

2. MLRiscGen:  forward propagating addresses from consing.

   I've changed the way consing code is generated.  Basically I separated 
   out the initialization part:

        store tag,   offset(allocptr)
        store elem1, offset+4(allocptr)
        store elem2, offset+8(allocptr)
        ...
        store elemn, offset+4n(allocptr)

   and the address computation part:

        celladdr <- offset+4+alloctpr

   and move the address computation part

   Effect:  register pressure is generally lower as a result.  This 
            makes compilation of certain expressions much faster, such as
            long lists with non-trivial elements.

             [(0,0), (0,0), .... (0,0)]

3. MLRiscGen: base pointer elimination.

    As part of the linkage mechanism, we generate the sequence:

     L:  ...  <- start of the code fragment
 
     L1:
         base pointer <- linkreg - L1 + L

     The base pointer was then used for computing relocatable addresses
   in the code fragment.  Frequently (such as in lots of continuations) 
   this is not needed.  We now eliminate this sequence whenever possible.

     For compile time efficiency, I'm using a very stupid local heuristic.  
   But in general, this should be done as a control flow analysis.

   Effect:  Smaller code size.  Speed up of most programs.

4. Hppa back end

     Long jumps in span dependence resolution used to depend on the existence
  of the base pointer.  

     A jump to a long label L was expanded into the following sequence:
     
      LDIL %hi(L-8192), %r29
      LDO  %lo(L-8192)(%r29), %r29
      ADD  %r29, baseptr, %r29
      BV,n %r0(%r29)

     In the presence of change (3) above, this will not work.  I've changed
   it so that the following sequence of instructions are generated, which
   doesn't mention the base pointer at all:

         BL,n  L', %r29           /* branch and link, L' + 4 -> %r29 */
    L':  ADDIL L-(L'+4), %r29     /* Compute address of L */ 
         BV,n  %r0(%r29)          /* Jump */ 

5. Alpha back end

      New alpha instructions LDB/LDW have been added, as per Fermin's
   suggestions.   This is unrelated to all other changes.

6. X86 back end 

     I've changed andl to testl in the floating point test sequence
     whenever appropriate.  The Intel optimization guide states that
     testl is perferable to andl.

7. RA (x86 only)

     I've improved the spill propagation algorithm, using an approximation
   of maximal weighted independent sets.   This seems to be necessary to
   alleviate the negative effect in light of the slow down in (1). 

     I'll write down the algorithm one of these days.

8. MLRiscGen: frequencies

     I've added an annotation that states that all call gc blocks have zero
   execution frequencies.  This improves register allocation on the x86.
    
BENCHMARKS
==========

   I've only perform the comparison on 110.25.

   The platforms are:
  
    HPPA  A four processor HP machine (E9000) with 5G of memory.
    X86   A 300Hhz Pentium II with 128M of memory, and 
    SPARC An Ultra sparc 2 with 512M of memory.

   I used the following parameters for the SML benchmarks:

             @SMLalloc
     HPPA    256k
     SPARC   512k
     X86     256k

COMPILATION TIME
----------------
   Here are the numbers comparing the compilation times of the compilers.
   I've only compared 110.25 compiling the new sources versus
   a fixpoint version of the new compiler compiling the same.

                 110.25                                  New
           Total  Time in RA  Spill+Reload   Total  Time In RA Spill+Reload
     HPPA   627s    116s        2684+3584     599s    95s       1003+1879
     SPARC  892s    173s        2891+3870     708s    116s      1004+1880
     X86    999s    315s       94006+130691   987s    296s    108877+141957

               110.25         New
            Code Size      Code Size
     HPPA   8596736         8561421
     SPARC  8974299         8785143
     X86    9029180         8716783

   So in summary, things are at least as good as before.   Dramatic 
   reduction in compilation is obtained on the Sparc; I can't explain it, 
   but it is reproducible.  Perhaps someone should try to reproduce this 
   on their own machines.

SML BENCHMARKS
--------------

    On the average, all benchmarks perform at least as well as before. 

      HPPA         Compilation Time     Spill+Reload      Run Time
                 110.25  New            110.25    New   110.25  New    

      barnesHut  3.158  3.015  4.75%    1+1       0+0   2.980  2.922   2.00%
          boyer  6.152  5.708  7.77%    0+0       0+0   0.218  0.213   2.34%
   count-graphs  1.168  1.120  4.32%    0+0       0+0  22.705 23.073  -1.60%
            fft  0.877  0.792 10.74%    1+3       1+3   0.602  0.587   2.56%
    knuthBendix  3.180  2.857 11.32%    0+0       0+0   0.675  0.662   2.02%
         lexgen  6.190  5.290 17.01%    0+0       0+0   0.913  0.788  15.86%
           life  0.803  0.703 14.22%   25+25      0+0   0.153  0.140   9.52%
          logic  2.048  2.007  2.08%    6+6       1+1   4.133  4.008   3.12%
     mandelbrot  0.077  0.080 -4.17%    0+0       0+0   0.765  0.712   7.49%
         mlyacc 22.932 20.937  9.53%  154+181    32+57  0.468  0.430   8.91%
        nucleic  5.183  5.060  2.44%    2+2       0+0   0.125  0.120   4.17%
  ratio-regions  3.357  3.142  6.84%    0+0       0+0  116.225 113.173 2.70%
            ray  1.283  1.290 -0.52%    0+0       0+0   2.887  2.855   1.11%
         simple  6.307  6.032  4.56%   28+30      5+7   3.705  3.658   1.28%
            tsp  0.888  0.862  3.09%    0+0       0+0   7.040  6.893   2.13%
           vliw 24.378 23.455  3.94%  106+127    25+45  2.758  2.707   1.91%
  --------------------------------------------------------------------------
   Average                     6.12%                                   4.09%

      SPARC        Compilation Time     Spill+Reload      Run Time
                 110.25  New            110.25    New   110.25  New    

      barnesHut  3.778  3.592  5.20%    2+2       0+0   3.648  3.453    5.65%
          boyer  6.632  6.110  8.54%    0+0       0+0   0.258  0.242    6.90%
   count-graphs  1.435  1.325  8.30%    0+0       0+0  33.672 34.737   -3.07%
            fft  0.980  0.940  4.26%    3+9       2+6   0.838  0.827    1.41%
    knuthBendix  3.590  3.138 14.39%    0+0       0+0   0.962  0.967   -0.52%
         lexgen  6.593  6.072  8.59%    1+1       0+0   1.077  1.078   -0.15%
           life  0.972  0.868 11.90%   26+26      0+0   0.143  0.140    2.38%
          logic  2.525  2.387  5.80%    7+7       1+1   5.625  5.158    9.05%
     mandelbrot  0.090  0.093 -3.57%    0+0       0+0   0.855  0.728   17.39%
         mlyacc 26.732 23.827 12.19%  162+189    32+57  0.550  0.560   -1.79%
        nucleic  6.233  6.197  0.59%    3+3       0+0   0.163  0.173   -5.77%
  ratio-regions  3.780  3.507  7.79%    0+0       0+0 133.993 131.035   2.26%
            ray  1.595  1.550  2.90%    1+1       0+0   3.440  3.418    0.63%
         simple  6.972  6.487  7.48%   29+32      5+7   3.523  3.525   -0.05%
            tsp  1.115  1.063  4.86%    0+0       0+0   7.393  7.265    1.77%
           vliw 27.765 24.818 11.87%  110+135    25+45  2.265  2.135    6.09%
  ----------------------------------------------------------------------------
   Average                     6.94%                                    2.64%

      X86          Compilation Time     Spill+Reload      Run Time
                 110.25  New            110.25    New   110.25  New    

      barnesHut  5.530  5.420  2.03%  593+893   597+915   3.532  3.440   2.66%
          boyer  8.768  7.747 13.19%  493+199   301+289   0.327  0.297  10.11%
   count-graphs  2.040  2.010  1.49%  298+394   315+457  26.578 28.660  -7.26%
            fft  1.327  1.302  1.92%  112+209   115+210   1.055  0.962   9.71%
    knuthBendix  5.218  5.475 -4.69%  451+598   510+650   0.928  0.932  -0.36%
         lexgen  9.970  9.623  3.60% 1014+841  1157+885   0.947  0.928   1.97%
           life  1.183  1.183  0.00%  162+182   145+148   0.127  0.103  22.58%
          logic  3.285  3.512 -6.45%  514+684   591+836   5.682  5.577   1.88%
     mandelbrot  0.147  0.143  2.33%   38+41     33+54    0.703  0.690   1.93%
         mlyacc 35.457 32.763  8.22% 3496+4564 3611+4860  0.552  0.550   0.30%
        nucleic  7.100  6.888  3.07%  239+168   201+158   0.175  0.173   0.96%
  ratio-regions  6.388  6.843 -6.65% 1182+257   981+300  120.142 120.345 -0.17%
            ray  2.332  2.338 -0.29%  346+398   402+494   3.593  3.540   1.51%
         simple  9.912  9.903  0.08% 1475+941  1579+1168  3.057  3.178  -3.83%
            tsp  1.623  1.532  5.98%  266+200   250+211   8.045  7.878   2.12%
           vliw 33.947 35.470 -4.29% 2629+2774 2877+3171  2.072  1.890   9.61%
  ----------------------------------------------------------------------------
   Average                     1.22%                                     3.36%

----------------------------------------------------------------------
Name: Allen Leung
Date: 2000/03/23 16:25:00
Tag: leunga-20000323-fix_x86_alpha
Description:

1. X86 fixes/changes  

   a.  The old code generated for SETcc was completely wrong.  
       The Intel optimization guide is VERY misleading.

2. ALPHA fixes/changes

   a.  Added the instructions LDBU, LDWU, STB, STW as per Fermin's suggestion.
   b.  Added a new mode byteWordLoadStores to the functor parameter to Alpha()
   c.  Added reassociation code for address computation.

----------------------------------------------------------------------
Name: Allen Leung
Date: 2000/03/22 01:23:00
Tag: leunga-20000322-fix_x86_hppa_ra
Description:

1. X86 fixes/changes  

   a.  x86Rewrite bug with MUL3 (found by Lal)
   b.  Added the instructions FSTS, FSTL

2. PA-RISC fixes/changes

   a.  B label should not be a delay slot candidate!  Why did this work?
   b.  ADDT(32, REG(32, r), LI n) now generates one instruction instead of two,
       as it should be.
   c.  The assembly syntax for fstds and fstdd was wrong.
   d.  Added the composite instruction COMICLR/LDO, which is the immediate
       operand variant of COMCLR/LDO.

3. Generic MLRISC

   a.  shuffle.sml rewritten to be slightly more efficient
   b.  DIV bug in mltree-simplify fixed (found by Fermin)

4. Register Allocator

   a.  I now release the interference graph earlier during spilling.
       May improve memory usage.  

----------------------------------------------------------------------
Name: Matthias Blume
Date: 2000/03/14 14:15:32
Tag: blume_main_v110p26p1_2
Description:

1. Tools.registerStdShellCmdTool (from smlnj/cm/tool.cm) takes an
additional argument called "template" which is an optional string that
specifiel the layout of the tool command line.  See the CM manual for
explanation.

2. A special-purpose tool can be "regisitered" by simply dropping the
corresponding <...>-tool.cm (and/or <...>-ext.cm) into the same
directory where the .cm file lives that uses this tool.  (The
behavior/misfeature until now was to look for the tool description
files in the current working directory.)  As before, tool description
files could also be anchored -- in which case they can live anywhere
they like.  Following the recent e-mail discussion, this change should
make it easier to have special-purpose tools that are shipped together
with the sources of the program that uses them.

----------------------------------------------------------------------
Name: Matthias Blume
Date: 2000/03/10 07:48:34
Tag: blume_main_v110p26p1_1
Description:

I added a re-written version of Dave's fixpt script to src/system.
Changes relative to the original version:
  - sh-ified (not everybody has ksh)
  - automatically figures out which architecture it runs on
  - uses ./makeml a bit more cleverly
  - never invokes ./installml (and, thus, does not clobber your
    good and working installation of sml in case something goes wrong)
  - accepts max iteration count using option "-iter <n>"
  - accepts a "base" name using option "-base <base>"

It does not build any extraneous heap images but directly rebuilds
bin- and boot-hierarchies using makeml's "-rebuild" switch. Finally,
it can incorporate existing bin- and boot- hierarchies.  For example,
suppose the base is set to "sml" (which is the default).  Then it
successively builds

        sml.bin.<arch>-unix and sml.boot.<arch>-unix
then    sml1.bin.<arch>-unix and sml1.boot.<arch>-unix
then    sml2.bin.<arch>-unix and sml2.boot.<arch>-unix
...
then    sml<n>.bin.<arch>-unix and sml<n>.boot.<arch>-unix

and so on.  If any of these already exist, it will just use what's
there.  In particular, many people will have the initial set of bin
and boot files around, so this saves time for at least one full
rebuild.  Having sets of the form <base><k>.{bin,boot}.<arch>-unix for
<k>=1,2,... is normally not a good idea when invoking fixpt.  However,
they might be the result of an earlier partial run of fixpt (which
perhaps got accidentially killed).  In this case, fixpt will quickly
move through what exists before continuing where it left off earlier,
and, thus, saves a lot of time.

----------------------------------------------------------------------
Name: Allen Leung
Date: 00/03/10 02:20:00
Tag: leunga-20000310-fix_x86_asm_ra
Description:

More assembly output problems involving the indexed addressing mode
on the x86 have been found and corrected. Thanks to Fermin Reig for the
fix.

The interface and implementation of the register allocator have been changed
slightly to accommodate the possibility to skip the register allocation 
phases completely and go directly to memory allocation.  This is needed
for C-- use.

----------------------------------------------------------------------
Name: Matthias Blume
Date: 00/03/09 10:23:53
Tag: blume_main_v110p26p1_0
Description:

* Complete re-organization of library names.  Many libraries have been
consolidated so that they share the same path anchor.  For example,
all MLRISC-related libraries are anchored at MLRISC, most libraries that
are SML/NJ-specific are under "smlnj".  Notice that names like
host-cmb.cm or host-compiler.cm no longer exist.  See system/README
for a complete description of the new naming scheme.  Quick reference:

   host-cmb.cm        -> smlnj/cmb.cm
   host-compiler.cm   -> smlnj/compiler.cm
   full-cm.cm         -> smlnj/cm.cm
   <arch>-<os>.cm     -> smlnj/cmb/<arch>-<os>.cm
   <arch>-compiler.cm -> smlnj/compiler/<arch>.cm

* Bug fixes in CM.
    - exceptions in user code are being passed through (i.e., reach top level)
    - more bugs in paranoia mode fixed
    - bug related to checking group owners fixed

* New install.sh script that automagically fetches archive files:
  The new file config/srcarchiveurl must contain the URL of the
  (remote) directory that contains bin files (or other source archives).
  If install.sh does not find the archive locally, it tries to get
  it from that remote directory.
  This should simplify installation further:  For machines that have
  access to the internet, just fetch <version>-config.tgz, unpack it,
  edit config/targets, and go (run config/install.sh).  The scipt will
  fetch everything else that it might need all by itself.

  For CVS users, this mechanism is not relevant for source archives, but
  it is convenient for getting new sets of binfiles.

  Archives should be tar files compressed with either gzip, compress, or
  bzip2.  The script recognizes .tgz, .tar, tar.gz, tz, .tar.Z, and .tar.bz2.
  
----------------------------------------------------------------------
Name: Matthias Blume
Date: 2000/03/07 04:01:04
Tag: blume_main_v110_26_2
Description:
- size info in BOOTLIST
     * no fixed upper limits for number of bootfiles or length of
       bootfile names in runtime
     * falling back to old behavior if no BOOTLIST size info found
- allocation size heuristics in .run-sml
     * tries to read cache size from /proc/cpuinfo (this is important for
        small-cache Celeron systems!)
- install.sh robustified
- CM manual updates
- paranoid mode
     * no more CMB.deliver() (i.e., all done by CMB.make())
     * can re-use existing sml.boot.* files
     * init.cmi now treated as library
     * library stamps for consistency checks
- sml.boot.<arch>-<os>/PIDMAP file
     * This file is read by the CM startup code.  This is used to minimize
       the amount of dynamic state that needs to be stowed away for the
       purpose of sharing between interactive system and user code.
- CM.Anchor.anchor instead of CM.Anchor.{set,cancel}
     * Upon request by Elsa.  Anchors now controlled by get-set-pair
       like most other CM state variables.
- Compiler.CMSA eliminated
     * No longer supported by CM anyway.
- fixed bugs in pickler that kept biting Stefan
     * past refs to past refs (was caused by the possibility that
       ad-hoc sharing is more discriminating than hash-cons sharing)
     * integer overflow on LargeInt.minInt
- ml-{lex,yacc} build scripts now use new mechanism
  for building standalone programs
- fixed several gcc -Wall warnings that were caused by missing header
  files, missing initializations, etc., in runtime (not all warnings
  eliminated, though)

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