What's new?

Fixed most bugs (in work)
bytecode: 12=>0, c: 7=>0, cc: 9=>5
5.10 and 5.12, non-threaded favored (faster)
.plc platform compatible, almost version compatible (.plc header change)
added testsuite
more and better optimisations (in work)
removed B::Stash bloat from perlcc, -stash [optional]

Who am I

rurban maintains cygwin perl since 5.8.8 and 3-4 modules, guts, B::* => 5.10

Mostly doing LISP Perl and PHP, and support for custom HW, windows + linux + real-time systems in real-life. Coding in winter, surfing in summer.

1995 first on CPAN with the perl5.hlp file and converter for Windows.

Started 1995 by Malcom Beattie, abandoned 2007 by p5p, revived 2008 by me

Very dynamic language. eval "require $foo;" -> which packages?

Overview
Status
Plans

Why use B::C / perlcc?

Improved startup time, esp. significant with larger code.
Reduced memory usage.
9% less memory w/ 25000 lines
Distribute binary only versions
- No need to ship an entire perl install
- Self contained application
- But you could also use a "Packager", like perl2exe, perlapp, PAR
  They are no compilers, slower startup
And with B::CC - Improve run-time

Overview

In the Perl Compiler suite B::C are three seperate compilers:

B::Bytecode / ByteLoader (freeze/thaw to .plc + .pmc)
B::C (freeze/thaw to .c)
B::CC (optimising to .c)

perl toke.c/op.c - B::C - perl op walker run.c

Eliminate the whole parsing and dynamic allocation time.

The Walker

After compilation walk the "op tree" - run.c

  int

  Perl_runops_standard(pTHX)

  {

   dVAR;

   while ((PL_op = CALL_FPTR(PL_op->op_ppaddr)(aTHX))) {

      PERL_ASYNC_CHECK();

   }

   TAINT_NOT;

   return 0;

  }

The Walker

   while ((PL_op = CALL_FPTR(PL_op->op_ppaddr)(aTHX))) {

      PERL_ASYNC_CHECK();

   }

Observation

1. The op tree is not a "tree", it is reduced to a simple linked list of ops. Every "op" (a pp_<opname> function) returns the next op.

2. PERL_ASYNC_CHECK is called after every single op.

Perl Phases - the "Perl Compiler"

=> Parse + Compile to op tree (in three phases, see perlguts and perloptree)
BEGIN (use ...)
CHECK (O modules)
INIT (main phase)
END (cleanup, perl destructors)

Normal Perl functions start at INIT, after BEGIN and CHECK.
The O modules start at CHECK, and skip INIT.

Perl Phases - the "B Compilers"

Parse + Compile to op tree (in three phases)
BEGIN (use ...)
=> CHECK (O) => freeze
compiled INIT (main phase)
compiled END (cleanup, perl destructors)

Perl Phases - the "B Compilers"

The B Compilers, invoked via O, freeze the state in CHECK, and invoke then the walker.

  $ perl -MO=C,-omyprog.c myprog.pl 

  $ cc_harness -o myprog myprog.c 

  $ ./myprog

B::CC - Unoptimised / the walker

  while ((PL_op = CALL_FPTR(PL_op->op_ppaddr)(aTHX))) {

        PERL_ASYNC_CHECK();

  }

B::CC - The optimiser / unrolled

  while ((PL_op = CALL_FPTR(PL_op->op_ppaddr)(aTHX))) {

        PERL_ASYNC_CHECK();

  }

  is unrolled to:

  lab_15de5b8:

   PUSHMARK(sp);

   XPUSHs(GvSVn((GV*)PL_curpad[1]));

   PL_op = (OP*)&listop_list[0];

   PUTBACK; PL_op = pp_print(); SPAGAIN;

  lab_1248c18:

   PP_UNSTACK;

   PERL_ASYNC_CHECK();

  /* next basic block */

B::CC - The optimiser / unrolled

no CALL_FPTR - call by ref
static direct function call
prefetched into CPU cache!
no unneeded stack handling
PERL_ASYNC_CHECK only after every basic block

Status

5.6.2 and 5.8.9 non-threaded B::C are quite usable and have the least known bugs, but 5.10 and 5.12 became also pretty stable now.

Targets:

Bugfixes for B::C
Test top100 CPAN modules (3-4 fail)
Isolate bugs into simple tests (35 cases)
Test the perl cores suite (~20 fails)
Estimated 3-4 more open bugs.

Status

5.6.2 + 5.8.9 are almost bug free, with B::Bytecode and B::C
B::C >=5.10 threaded (pads) in work
2-3 minor bugs with certain modules
With debugging perls there seem to be less bugs than with releases. Normally it 's the other way round
B::CC has some limitations and some known bugs
See testsuite and STATUS

Projects