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llvm-6502/lib/Target/IA64
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Duraid Madina e8fd25f5c5 * OK, after changing to use liveIn/liveOut instead of IDEFs, 
to avoid redundant mov out3=r44 type instructions, we need to
tell the register allocator the truth about out? registers.

FIXME: unfortunately, since the list of allocatable registers is immutable,
we can't simply 'delete r127' from the allocation order, say, if 'out0' is
used. The only correct thing we can do is have a linear order of regs:

out7, out6 ... out2, out1, out0, r32, r33, r34 ... r126, r127

and slide a 'window' of 96 registers along this line, depending on how many
of the out? regs a function actually uses. The only downside of this is
that the out? registers will be allocated _first_, which makes the
resulting assembly ugly. :( Note this in the README. Hope this gets fixed
soon. :) (note the 3rd person speech there)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21252 91177308-0d34-0410-b5e6-96231b3b80d8
2005-04-12 18:42:59 +00:00
..
IA64.h and so it begins... 2005-03-17 18:17:03 +00:00
IA64.td lie a bit and say that r1/r12 (GP/SP) _aren't_ callee-save, as we take 2005-04-06 06:18:36 +00:00
IA64AsmPrinter.cpp assorted fixes: 2005-04-11 05:55:56 +00:00
IA64InstrBuilder.h and so it begins... 2005-03-17 18:17:03 +00:00
IA64InstrFormats.td and so it begins... 2005-03-17 18:17:03 +00:00
IA64InstrInfo.cpp and so it begins... 2005-03-17 18:17:03 +00:00
IA64InstrInfo.h and so it begins... 2005-03-17 18:17:03 +00:00
IA64InstrInfo.td Make sure to realize that calls use their argument regs 2005-04-12 15:12:19 +00:00
IA64ISelPattern.cpp stop emitting IDEFs for args - change to using liveIn/liveOut 2005-04-12 14:54:44 +00:00
IA64MachineFunctionInfo.h and so it begins... 2005-03-17 18:17:03 +00:00
IA64RegisterInfo.cpp assorted fixes: 2005-04-11 05:55:56 +00:00
IA64RegisterInfo.h and so it begins... 2005-03-17 18:17:03 +00:00
IA64RegisterInfo.td * OK, after changing to use liveIn/liveOut instead of IDEFs, 2005-04-12 18:42:59 +00:00
IA64TargetMachine.cpp and so it begins... 2005-03-17 18:17:03 +00:00
IA64TargetMachine.h and so it begins... 2005-03-17 18:17:03 +00:00
Makefile OK, IA64 is statically linked into llc 2005-03-17 18:37:05 +00:00
README * OK, after changing to use liveIn/liveOut instead of IDEFs, 2005-04-12 18:42:59 +00:00

README 

*** README for the LLVM IA64 Backend "Version 0.01" - March 18, 2005
*** Quote for this version:

      "Kaori and Hitomi are naughty!!"


Congratulations, you have found:

**************************************************************** 
* @@@       @@@       @@@  @@@  @@@@@@@@@@                     *
* @@@       @@@       @@@  @@@  @@@@@@@@@@@                    *
* @@!       @@!       @@!  @@@  @@! @@! @@!                    *
* !@!       !@!       !@!  @!@  !@! !@! !@!                    *
* @!!       @!!       @!@  !@!  @!! !!@ @!@                    *
* !!!       !!!       !@!  !!!  !@!   ! !@!                    *
* !!:       !!:       :!:  !!:  !!:     !!:                    *
*  :!:       :!:       ::!!:!   :!:     :!:                    *
*  :: ::::   :: ::::    ::::    :::     ::                     *
* : :: : :  : :: : :     :       :      :                      *
*                                                              *
*                                                              *
*  @@@@@@   @@@  @@@       @@@   @@@@@@     @@@@@@       @@@   *
* @@@@@@@@  @@@@ @@@       @@@  @@@@@@@@   @@@@@@@      @@@@   *
* @@!  @@@  @@!@!@@@       @@!  @@!  @@@  !@@          @@!@!   *
* !@!  @!@  !@!!@!@!       !@!  !@!  @!@  !@!         !@!!@!   *
* @!@  !@!  @!@ !!@!       !!@  @!@!@!@!  !!@@!@!    @!! @!!   *
* !@!  !!!  !@!  !!!       !!!  !!!@!!!!  @!!@!!!!  !!!  !@!   *
* !!:  !!!  !!:  !!!       !!:  !!:  !!!  !:!  !:!  :!!:!:!!:  *
* :!:  !:!  :!:  !:!       :!:  :!:  !:!  :!:  !:!  !:::!!:::  *
* ::::: ::   ::   ::        ::  ::   :::  :::: :::       :::   *
*  : :  :   ::    :        :     :   : :   :: : :        :::   *
*                                                              *
****************************************************************
* Bow down, bow down, before the power of IA64! Or be crushed, *
* be crushed, by its jolly registers of doom!!                 *
****************************************************************

DEVELOPMENT PLAN:

   _  you are       2005           maybe 2005       2006            2006 and
  /   here            |               |              |               beyond 
 v                    v               v              v                |
                                                                      v
CLEAN UP        ADD INSTRUCTION      ADD          PLAY WITH
INSTRUCTION --> SCHEDULING AND  -->  JIT    -->    DYNAMIC     --> FUTURE WORK
SELECTION       BUNDLING            SUPPORT     REOPTIMIZATION

DISCLAIMER AND PROMISE:

As of the time of this release, you are probably better off using Intel C/C++
or GCC. The performance of the code emitted right now is, in a word,
terrible. Check back in a few months - the story will be different then,
I guarantee it.

TODO:

  - clean up and thoroughly test the isel patterns.
  - fix stacked register allocation order: (for readability) we don't want
    the out? registers being the first ones used
  - fix up floating point
    (nb http://gcc.gnu.org/wiki?pagename=ia64%20floating%20point )
  - bundling!
    (we will avoid the mess that is:
     http://gcc.gnu.org/ml/gcc/2003-12/msg00832.html )
  - instruction scheduling (yep)
  - write truly inspirational documentation
  - if-conversion (predicate database/knowledge? etc etc)
  - counted loop support
  - make integer + FP mul/div more clever (we have fixed pseudocode atm)
  - track and use comparison complements

INFO:

  - we are strictly LP64 here, no support for ILP32 on HP-UX. Linux users
    don't need to worry about this.
  - i have instruction scheduling/bundling pseudocode, that really works
    (has been tested, albeit at the perl-script level).
    so, before you go write your own, send me an email!

KNOWN DEFECTS AT THE CURRENT TIME:

  - C++ vtables contain naked function pointers, not function descriptors,
  which is bad. see http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=406
  - varargs are broken
  - alloca doesn't work (indeed, stack frame layout is bogus)
  - no support for big-endian environments
  - (not really the backend, but...) the CFE has some issues on IA64.
    these will probably be fixed soon.
  
ACKNOWLEDGEMENTS:

  - Chris Lattner (x100)
  - Other LLVM developers ("hey, that looks familiar")

CONTACT:

  - You can email me at duraid@octopus.com.au. If you find a small bug,
    just email me. If you find a big bug, please file a bug report
    in bugzilla! http://llvm.cs.uiuc.edu is your one stop shop for all
    things LLVM.