Offline Narrowing-Driven Specialization in Practice

In order to compare  the Offline strategies with the Online Partial Evaluator, we have made a slight modification to the online partial evaluator and we have adapted also the same examples for both classes of partial evaluators, the sources of this last application can be found in this hiperlink. Once you download the file, you can uncompress it with:

  tar xvfz peval07.tgz

If you have installed PAKCS goto to load  the file peval.curry, otherwise;  you need to install the PAKCS (version 1.7.3) environment for Curry. Then, start PAKCS and load  the file peval.curry as follows:

[gustavo@cmm2 test]$ cd peval
[gustavo@cmm2 peval]$ pakcs
% restoring /usr/local/pakcs/curry2prolog/c2p.state...
  ______      __       _    _    ______   _______    
 |  __  |    /  \     | |  / /  |  ____| |  _____|   Portland Aachen Kiel
 | |  | |   / /\ \    | |_/ /   | |      | |_____    Curry System
 | |__| |  / /__\ \   |  _  |   | |      |_____  |  
 |  ____| / ______ \  | | \ \   | |____   _____| |   Version 1.7.3 (10)
 |_|     /_/      \_\ |_|  \_\  |______| |_______|   September 2006

Curry2Prolog(sicstus) Compiler Environment (Version of 15/09/06)
(RWTH Aachen, CAU Kiel, Portland State University)

Bug reports: mh@informatik.uni-kiel.de

Type ":h" for help

Prelude> :l peval
Parsing 'peval.curry'...
...
generating peval.fcy ...
peval>

Now, you have available the following command:

• mixon "program": it takes the program and computes  directly the partial evaluation of it. The user just need to indicate in the source program  the expressions to be partially evaluated by means the PEVAL identity function, although all the included examples have been adapted please check the German Vidal page of Partial Evaluation of Functional (Logic) Languages for better explanation.

For instance, a typical session is as follows:

peval> mixon "onexamp/applastSD"
Curry Partial Evaluator (Version 1.4 of November 2006)
(UP Valencia, CAU Kiel)

Annotated expressions to be partially evaluated:

(applastSD.applast (: 1 (: 2 (: 3 (: 4 (: 5 ([] )))))) v1)

Starting peval for program "onexamp/applastSD"...

Independent Renaming:

Specialized Program:

After Post-unfolding:

Writing specialized program into "onexamp/applastSD_pe.fcy"...

Specialization time (msecs): 1290
peval> :q
[gustavo@cmm2 peval]$
 

As you can see the application gives the specialization time also. You can load the specialized program (the benchmark) to verify the average benchmark runtime, we show below how to run the applast_pe.fcy benchmark:
 

[gustavo@cmm2 peval]$ pakcs
% restoring /usr/local/pakcs/curry2prolog/c2p.state...
  ______      __       _    _    ______   _______    
 |  __  |    /  \     | |  / /  |  ____| |  _____|   Portland Aachen Kiel
 | |  | |   / /\ \    | |_/ /   | |      | |_____    Curry System
 | |__| |  / /__\ \   |  _  |   | |      |_____  |  
 |  ____| / ______ \  | | \ \   | |____   _____| |   Version 1.7.3 (10)
 |_|     /_/      \_\ |_|  \_\  |______| |_______|   September 2006

Curry2Prolog(sicstus) Compiler Environment (Version of 15/09/06)
(RWTH Aachen, CAU Kiel, Portland State University)

Bug reports: mh@informatik.uni-kiel.de

Type ":h" for help

Prelude> :l peval
Parsing 'peval.curry'...
skipping Flat.curry ...
skipping Flat2Fcy.curry ...
skipping peval.curry ...
peval> mixon "onexamp/applast"
Curry Partial Evaluator (Version 1.4 of November 2006)
(UP Valencia, CAU Kiel)

Annotated expressions to be partially evaluated:

(applast.applast v1 6)

Starting peval for program "onexamp/applast"...

Independent Renaming:

Specialized Program:

After Post-unfolding:

Writing specialized program into "onexamp/applast_pe.fcy"...

Specialization time (msecs): 250
peval> :l onexamp/applast_pe
Compiling 'onexamp/applast_pe.fcy' into 'onexamp/applast_pe.pl'...done
onexamp/applast_pe(module: applast)> bench
success
success
success
success
success
success
success
success
success
success
Runtimes (msecs): [1170,1170,1060,1110,1160,1080,1120,1090,1130,1100]
Average (msecs): 1119
onexamp/applast_pe(module: applast)>
 

After you get the specialized program, applast_pe.fcy in this case, you can load it and execute the bench function; this function executes ten times the program and gives de average in milisecs.

The sources of the Offline strategies adapted to show the specialization time can be found in this hiperlink. Once you download the file, you can proceed as is indicated in this page. You will see the specialization time when you execute mix or mixpo, i.e., hybrid or pure offline specialization. For instance:

OffPeval> annotate "examples/applast"
--------------------------------------------------
         Offline Partial Evaluator v 1.0         
--------------------------------------------------
Loading AbstractCurry program
Computing size-change graphs
Computing binding-time division
[("main",1,[D]),("applast",2,[D,S]),("app",2,[D,S]),("last",1,[D]),("UNF",1,[S]),("MEM",1,[S]),("GEN",1,[S]),("getExecTime",1,[S]),("runBenchmark",2,[S,S])]
Program loaded
Annotating program & linearizing...
Program succesfully annotated
Tranforming annotated program to Curry...
Annotated program stored in <<examples/applast_ann.curry>>
OffPeval> mix "examples/applast_ann"
Offline Narrowing-Driven Partial Evaluator
(Version 0.1 of April 2007)
(Technical University of Valencia)

Main call: (main v0)

Writing original program into "examples/applast_ann_pe.fcy"...

Global & local acceses:"
5"  13

Specialization time (msecs): 200
OffPeval> :l examples/applast_ann_pe
Compiling 'examples/applast_ann_pe.fcy' into 'examples/applast_ann_pe.pl'...done
examples/applast_ann_pe(module: applast_ann)> bench
success
success
success
success
success
success
success
success
success
success
Runtimes (msecs): [1180,1180,1180,1190,1190,1170,1190,1180,1180,1190]
Average (msecs): 1183
examples/applast_ann_pe(module: applast_ann)> :q
 

Please report any bug or comment to garroyo (at) dsic.upv.es.

Last update / Gustavo Arroyo