[Bug target/63762] [ARM]GCC generates UNPREDICTABLE STR with Rn = Rt when hard-float abi is used

[Bug target/63762] [ARM]GCC generates UNPREDICTABLE STR with Rn = Rt when hard-float abi is used

[renlin.li at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63762

--- Comment #1 from Renlin Li <renlin.li at arm dot com> ---
I am starting to work on this issue.

[Bug target/63762] [ARM]GCC generates UNPREDICTABLE STR with Rn = Rt when hard-float abi is used

[ramana at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63762

Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2014-11-10
                 CC|                            |ramana at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |renlin.li at arm dot com
   Target Milestone|---                         |5.0
     Ever confirmed|0                           |1

[Bug target/63762] [ARM]GCC generates UNPREDICTABLE STR with Rn = Rt when hard-float abi is used

[renlin.li at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63762

--- Comment #2 from Renlin Li <renlin.li at arm dot com> ---
r278 is derived from r224 which is a VFP_LO_REGS.

find_cost_and_classes assigns r278's class as GENERAL_REGS, and assign it
hard_reg 2. Another new pseudo register r290 is created from r278, and assigned
to the same hard_register and register class (GENERAL_REGS).

The pref_class of r290 is derived from its original reg (r224), which is
VFP_LO_REGS

In lra during the hard register assignment process, conflict is checked for
r302 which is a GENERAL_REGS. r290 is not considered, because of different
register classes(reg_pref[290].pref_class == VFP_LO_REGS ). Hard register
number 2 is chosen in this case.

[Bug target/63762] [ARM]GCC generates UNPREDICTABLE STR with Rn = Rt when hard-float abi is used

[renlin.li at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63762

--- Comment #3 from Renlin Li <renlin.li at arm dot com> ---
Created attachment 33957
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33957&action=edit
ira dump

[Bug target/63762] [ARM]GCC generates UNPREDICTABLE STR with Rn = Rt when hard-float abi is used

[ramana at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63762

--- Comment #4 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
(In reply to Renlin Li from comment #2)
> r278 is derived from r224 which is a VFP_LO_REGS.
> 
> find_cost_and_classes assigns r278's class as GENERAL_REGS, and assign it
> hard_reg 2. Another new pseudo register r290 is created from r278, and
> assigned to the same hard_register and register class (GENERAL_REGS).
> 
> The pref_class of r290 is derived from its original reg (r224), which is
> VFP_LO_REGS
> 
> In lra during the hard register assignment process, conflict is checked for
> r302 which is a GENERAL_REGS. r290 is not considered, because of different
> register classes(reg_pref[290].pref_class == VFP_LO_REGS ). Hard register
> number 2 is chosen in this case.

R2 should not be in VFP_LO_REGS - how does IRA end up choosing that ?

[Bug middle-end/63762] [ARM]GCC generates UNPREDICTABLE STR with Rn = Rt when hard-float abi is used

[renlin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63762

--- Comment #5 from renlin at gcc dot gnu.org ---
Author: renlin
Date: Wed Nov 19 15:15:51 2014
New Revision: 217783

URL: https://gcc.gnu.org/viewcvs?rev=217783&root=gcc&view=rev
Log:
2014-11-19  Renlin Li  <Renlin.Li@arm.com>

        PR middle-end/63762
        * ira.c (ira): Update preferred class. 

        * gcc.dg/pr63762.c: New test. 

Added:
    trunk/gcc/testsuite/gcc.dg/pr63762.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/ira.c
    trunk/gcc/testsuite/ChangeLog

[Bug middle-end/63762] [ARM]GCC generates UNPREDICTABLE STR with Rn = Rt when hard-float abi is used

[renlin.li at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63762

Renlin Li <renlin.li at arm dot com> changed:

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

--- Comment #6 from Renlin Li <renlin.li at arm dot com> ---
fix r217783

[Bug middle-end/63762] [ARM]GCC generates UNPREDICTABLE STR with Rn = Rt when hard-float abi is used

[rearnsha at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63762

Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |doko at gcc dot gnu.org

--- Comment #7 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
*** Bug 63749 has been marked as a duplicate of this bug. ***

[Bug middle-end/63762] [ARM]GCC generates UNPREDICTABLE STR with Rn = Rt when hard-float abi is used

[renlin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63762

--- Comment #8 from renlin at gcc dot gnu.org ---
Author: renlin
Date: Wed Dec  3 11:13:50 2014
New Revision: 218306

URL: https://gcc.gnu.org/viewcvs?rev=218306&root=gcc&view=rev
Log:
Backported from mainline

gcc/

2014-12-03  Renlin Li  <Renlin.Li@arm.com>

    PR middle-end/63762
    PR target/63661
    * ira.c (i386ra): Update preferred class.

gcc/testsuite/

2014-12-03  Renlin Li  <Renlin.Li@arm.com>
        H.J. Lu <hongjiu.lu@intel.com>

    PR middle-end/63762
    PR target/63661
    * gcc.dg/pr63762.c: New test.
    * gcc.target/i386/pr63661.c: New test.

Added:
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/pr63762.c
    branches/gcc-4_9-branch/gcc/testsuite/gcc.target/i386/pr63661.c
Modified:
    branches/gcc-4_9-branch/gcc/ChangeLog
    branches/gcc-4_9-branch/gcc/ira.c
    branches/gcc-4_9-branch/gcc/testsuite/ChangeLog