[Bug ada/24857] New: ada/s-auxdec.ads alignment issue for arm-rtems

[Bug ada/24857] New: ada/s-auxdec.ads alignment issue for arm-rtems

[laurent at guerby dot net]

>From Joel Sherrill:

Gcc on the head  fails to compile arm-rtems4.7 at the following point
when Ada is enabled.

../../xgcc -B../../  -c -g -O2      -W -Wall -gnatpg  s-auxdec.adb -o 
s-auxdec.o
s-auxdec.ads:286:13: alignment for "Aligned_Word" must be at least 4

The code is:

   type Aligned_Word is record
      Value : Short_Integer;
   end record;

   for Aligned_Word'Alignment use
      Integer'Min (2, Standard'Maximum_Alignment);

I (Laurent) think Standard'Maximum_Alignment comes from ada/targtyps.c

get_target_maximum_alignment (void)
{
  return BIGGEST_ALIGNMENT / BITS_PER_UNIT;
}

Joel confirmed that changing "Min (2" to "Min (4" enable this file to be
compiled, however my reading of the source would imply that BIGGEST_ALIGNMENT
is at least 32 on arm, so something else must be at play here, any idea?


-- 
           Summary: ada/s-auxdec.ads alignment issue for arm-rtems
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: build
          Severity: normal
          Priority: P3
         Component: ada
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: laurent at guerby dot net
GCC target triplet: arm-rtems


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24857

[Bug ada/24857] ada/s-auxdec.ads alignment issue for arm-rtems

[ebotcazou at gcc dot gnu dot org]

------- Comment #1 from ebotcazou at gcc dot gnu dot org  2005-11-14 20:37 -------
> Joel confirmed that changing "Min (2" to "Min (4" enable this file to be
> compiled, however my reading of the source would imply that BIGGEST_ALIGNMENT
> is at least 32 on arm, so something else must be at play here, any idea?

Excerpt from config/arm/arm.h:

/* Setting STRUCTURE_SIZE_BOUNDARY to 32 produces more efficient code, but the
   value set in previous versions of this toolchain was 8, which produces more
   compact structures.  The command line option -mstructure_size_boundary=<n>
   can be used to change this value.  For compatibility with the ARM SDK
   however the value should be left at 32.  ARM SDT Reference Manual (ARM DUI
   0020D) page 2-20 says "Structures are aligned on word boundaries".
   The AAPCS specifies a value of 8.  */
#define STRUCTURE_SIZE_BOUNDARY arm_structure_size_boundary
extern int arm_structure_size_boundary;

/* This is the value used to initialize arm_structure_size_boundary.  If a
   particular arm target wants to change the default value it should change
   the definition of this macro, not STRUCTURE_SIZE_BOUNDARY.  See netbsd.h
   for an example of this.  */
#ifndef DEFAULT_STRUCTURE_SIZE_BOUNDARY
#define DEFAULT_STRUCTURE_SIZE_BOUNDARY 32
#endif


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ebotcazou at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24857

[Bug ada/24857] ada/s-auxdec.ads alignment issue for arm-rtems

[ebotcazou at gcc dot gnu dot org]

-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-11-14 20:37:55
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24857

[Bug ada/24857] ada/s-auxdec.ads alignment issue for arm-rtems

[guerby at gcc dot gnu dot org]

------- Comment #2 from guerby at gcc dot gnu dot org  2005-11-17 11:13 -------
Subject: Bug 24857

Author: guerby
Date: Thu Nov 17 11:13:18 2005
New Revision: 107116

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=107116
Log:
2005-11-17  Laurent GUERBY  <laurent@guerby.net>

        PR ada/24857
        * s-auxdec-empty.ads, s-auxdec-empty.adb: New files.


Added:
    trunk/gcc/ada/s-auxdec-empty.adb
    trunk/gcc/ada/s-auxdec-empty.ads
Modified:
    trunk/gcc/ada/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24857

[Bug ada/24857] ada/s-auxdec.ads alignment issue for arm-rtems

[guerby at gcc dot gnu dot org]

------- Comment #3 from guerby at gcc dot gnu dot org  2005-11-18 11:44 -------
Subject: Bug 24857

Author: guerby
Date: Fri Nov 18 11:44:20 2005
New Revision: 107175

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=107175
Log:
2005-11-18  Laurent GUERBY  <laurent@guerby.net>

        PR ada/24857
        * Makefile.in: Use s-auxdec-empty for RTEMS.



Modified:
    trunk/gcc/ada/ChangeLog
    trunk/gcc/ada/Makefile.in


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24857

[Bug ada/24857] ada/s-auxdec.ads alignment issue for arm-rtems

[joel at gcc dot gnu dot org]

------- Comment #4 from joel at gcc dot gnu dot org  2005-11-18 21:16 -------
arm-rtems4.7 now builds.  The empty version is used for all RTEMS target.

Thanks.


-- 

joel at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24857

[Bug ada/24857] ada/s-auxdec.ads alignment issue for arm-rtems

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24857