[Bug target/61098] New: Poor code setting count register for large loops

[Bug target/61098] New: Poor code setting count register for large loops

[amodra at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61098

            Bug ID: 61098
           Summary: Poor code setting count register for large loops
           Product: gcc
           Version: 4.10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: amodra at gmail dot com

Seen on a for (i = 0; i < 100000000; i++) loop

    100003bc:   3d 20 05 f5     lis     r9,1525
    100003c0:   7d 29 03 a6     mtctr   r9
    100003c4:   7d 3e 1a 14     add     r9,r30,r3
    100003c8:   7d 49 02 a6     mfctr   r10
    100003cc:   61 4a e1 00     ori     r10,r10,57600
    100003d0:   7d 49 03 a6     mtctr   r10

Note the horrible mtctr, mfctr, mtctr

[Bug target/61098] Poor code setting count register for large loops

[amodra at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61098

Alan Modra <amodra at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |powerpc64-linux,
                   |                            |powerpc64le-linux
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2014-05-07
           Assignee|unassigned at gcc dot gnu.org      |amodra at gmail dot com
     Ever confirmed|0                           |1

[Bug target/61098] Poor code setting count register for large loops

[amodra at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61098

--- Comment #1 from Alan Modra <amodra at gmail dot com> ---
Created attachment 32754
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32754&action=edit
testcase

[Bug target/61098] Poor code setting count register for large loops

[amodra at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61098

--- Comment #2 from Alan Modra <amodra at gcc dot gnu.org> ---
Author: amodra
Date: Mon May 26 13:09:48 2014
New Revision: 210932

URL: http://gcc.gnu.org/viewcvs?rev=210932&root=gcc&view=rev
Log:
    PR target/61098
    * config/rs6000/rs6000.c (rs6000_emit_set_const): Remove unneeded
    params and return a bool.  Remove dead code.  Update comment.
    Assert we have a const_int source.  Remove bogus code from
    32-bit HWI days.  Move !TARGET_POWERPC64 handling, and correct
    handling of constants > 2G and reg_equal note, from..
    (rs6000_emit_set_long_const): ..here.  Remove unneeded param and
    return value.  Update comment.  If we can, use a new pseudo
    for intermediate calculations.
    * config/rs6000/rs6000-protos.h (rs6000_emit_set_const): Update
    prototype.
    * config/rs6000/rs6000.md (movsi_internal1_single+1): Update
    call to rs6000_emit_set_const in splitter.
    (movdi_internal64+2, +3): Likewise.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/rs6000/rs6000-protos.h
    trunk/gcc/config/rs6000/rs6000.c
    trunk/gcc/config/rs6000/rs6000.md

[Bug target/61098] Poor code setting count register for large loops

[amodra at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61098

Alan Modra <amodra at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
                URL|http://gcc.gnu.org/ml/gcc-p |https://gcc.gnu.org/ml/gcc-
                   |atches/2014-05/msg00451.htm |patches/2014-05/msg02024.ht
                   |l                           |ml
         Resolution|---                         |FIXED
   Target Milestone|---                         |4.10.0

--- Comment #3 from Alan Modra <amodra at gmail dot com> ---
Fixed mainline