[Bug target/50887] New: [avr] Support ACCUMULATE_OUTGOING_ARGS

[Bug target/50887] New: [avr] Support ACCUMULATE_OUTGOING_ARGS

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50887

             Bug #: 50887
           Summary: [avr] Support ACCUMULATE_OUTGOING_ARGS
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: gjl@gcc.gnu.org
                CC: eric.weddington@atmel.com
            Target: avr


Supporting accumulate outgoing arguments can reduce code size in functions that
call functions which get their arguments on the stack more than once
(statically).

[Bug target/50887] [avr] Support ACCUMULATE_OUTGOING_ARGS

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50887

--- Comment #1 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-10-27 18:01:17 UTC ---
Created attachment 25636
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25636
aoa.c

C source file that has several call to printf-ish function.

With the current implementation, after each call the code must get rid of the
pushed arguments which is expensive as SP cannot be modified directly.

Compile with, e.g., 

$ avr-gcc aoa.c -S -Os -mmcu=avr4

[Bug target/50887] [avr] Support ACCUMULATE_OUTGOING_ARGS

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50887

Georg-Johann Lay <gjl at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011-10-27
         AssignedTo|unassigned at gcc dot       |gjl at gcc dot gnu.org
                   |gnu.org                     |
   Target Milestone|---                         |4.7.0
     Ever Confirmed|0                           |1

[Bug target/50887] [avr] Support ACCUMULATE_OUTGOING_ARGS

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50887

--- Comment #2 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-10-29 14:36:05 UTC ---
Author: gjl
Date: Sat Oct 29 14:35:59 2011
New Revision: 180654

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=180654
Log:
    PR target/50887
    * config/avr/avr.opt (-maccumulate-args): New option.
    * config/avr/avr.h (STARTING_FRAME_OFFSET): Redefine to
    avr_starting_frame_offset.
    (ACCUMULATE_OUTGOING_ARGS): Define to avr_accumulate_outgoing_args.
    * config/avr/avr.md (UNSPECV_WRITE_SP_IRQ_ON): Remove.
    (UNSPECV_WRITE_SP_IRQ_OFF): Remove.
    (UNSPECV_WRITE_SP): New constant.
    (*addhi3_sp_R): Rewrite to...
    (*addhi3_sp): ...this new insn.
    (movhi_sp_r_irq_off, movhi_sp_r_irq_on): Combine to...
    (movhi_sp_r): ...this new insn.
    * config/avr/avr-protos.h (avr_accumulate_outgoing_args): New.
    (avr_starting_frame_offset): New.
    * config/avr/avr.c (avr_accumulate_outgoing_args): New function.
    (avr_starting_frame_offset): New function.
    (avr_outgoing_args_size): New static function.
    (avr_initial_elimination_offset): Use it.
    (avr_simple_epilogue): Use it.
    (avr_asm_function_end_prologue): Use it.
    (expand_epilogue): Use it.
    (expand_prologue): Use it.  Break out code to...
    (avr_prologue_setup_frame): ...this new static function.
    (avr_can_eliminate): Allow eliminating to frame pointer if there
    is one.
    (avr_frame_pointer_required_p): Use frame pointer if target has a
    nonlocal label.
    * config/avr/constraints.md (R): Remove.
    (Csp): New constraint.
    * config/avr/predicates.md (avr_sp_immediate_operand): Use it.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/avr/avr-protos.h
    trunk/gcc/config/avr/avr.c
    trunk/gcc/config/avr/avr.h
    trunk/gcc/config/avr/avr.md
    trunk/gcc/config/avr/avr.opt
    trunk/gcc/config/avr/constraints.md
    trunk/gcc/config/avr/predicates.md

[Bug target/50887] [avr] Support ACCUMULATE_OUTGOING_ARGS

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50887

--- Comment #3 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2012-01-20 12:31:59 UTC ---
Author: gjl
Date: Fri Jan 20 12:31:46 2012
New Revision: 183336

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=183336
Log:
    PR target/49868
    PR target/50887
    * doc/extend.texi (Named Address Spaces): Split into subsections.
    (AVR Named Address Spaces): New subsection.
    (M32C Named Address Spaces): New subsection.
    (RL78 Named Address Spaces): New subsection.
    (SPU Named Address Spaces): New subsection.
    (Variable Attributes): New anchor "AVR Variable Attributes".
    (AVR Variable Attributes): Rewrite and avoid wording
    "address space" in this context.
    * doc/invoke.texi (AVR Options): Rewrite and add documentation
    for -maccumulate-args, -mbranch-cost=, -mrelax, -mshort-calls.
    (AVR Built-in Macros): New subsubsection therein.
    * doc/md.texi (AVR constraints): Remove "C04", "R".


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/doc/extend.texi
    trunk/gcc/doc/invoke.texi
    trunk/gcc/doc/md.texi

[Bug target/50887] [avr] Support ACCUMULATE_OUTGOING_ARGS

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50887

Georg-Johann Lay <gjl at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|documentation               |
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #4 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2012-01-20 12:33:45 UTC ---
Closed with its documentation