[Bug target/67745] [ARM] wrong alignments when __attribute__ ((optimize,target,align) is used

[chrbr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67745

--- Comment #6 from chrbr at gcc dot gnu.org ---
Author: chrbr
Date: Fri Oct 16 13:37:14 2015
New Revision: 228904

URL: https://gcc.gnu.org/viewcvs?rev=228904=gcc=rev
Log:
2015-10-16  Christian Bruel  

PR target/67745
* config/arm/arm.h (FUNCTION_BOUNDARY): Move optimize_size condition
to:
* config/arm/arm.c (arm_option_override_internal): Call
arm_override_options_after_change_1.
(arm_override_options_after_change): New function.
(arm_override_options_after_change_1): Likewise.
(TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE): Define hook.


Added:
trunk/gcc/testsuite/gcc.target/arm/attr-align1.c
trunk/gcc/testsuite/gcc.target/arm/attr-align2.c
trunk/gcc/testsuite/gcc.target/arm/attr-align3.c
trunk/gcc/testsuite/gcc.target/arm/no-align.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/config/arm/arm.c
trunk/gcc/config/arm/arm.h
trunk/gcc/testsuite/ChangeLog

[Bug target/67745] [ARM] wrong alignments when __attribute__ ((optimize,target,align) is used

[chrbr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67745

--- Comment #7 from chrbr at gcc dot gnu.org ---
Author: chrbr
Date: Fri Oct 16 13:52:51 2015
New Revision: 228912

URL: https://gcc.gnu.org/viewcvs?rev=228912=gcc=rev
Log:
2015-10-16  Christian Bruel  

PR target/67745
* config/arm/arm.h (FUNCTION_BOUNDARY): Use FUNCTION_BOUNDARY_P.
(FUNCTION_BOUNDARY_P): New macro:
* config/arm/arm.c (TARGET_RELAYOUT_FUNCTION, arm_relayout_function): 
New hook.
* doc/tm.texi.in (TARGET_RELAYOUT_FUNCTION): Document.
* doc/tm.texi (TARGET_RELAYOUT_FUNCTION): New hook.
* gcc/target.def (TARGET_RELAYOUT_FUNCTION): Likewise.
* gcc/function.c (allocate_struct_function): Call relayout_function
hook.
* gcc/passes.c (rest_of_decl_compilation): Likewise.


Modified:
trunk/gcc/ChangeLog
trunk/gcc/config/arm/arm.c
trunk/gcc/config/arm/arm.h
trunk/gcc/doc/tm.texi
trunk/gcc/doc/tm.texi.in
trunk/gcc/function.c
trunk/gcc/passes.c
trunk/gcc/target.def

[Bug target/67745] [ARM] wrong alignments when __attribute__ ((optimize,target,align) is used

[chrbr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67745

chrbr at gcc dot gnu.org changed:

   What|Removed |Added

 Status|ASSIGNED|RESOLVED
 Resolution|--- |FIXED

--- Comment #8 from chrbr at gcc dot gnu.org ---
fixed at rev 228912

[Bug target/67745] [ARM] wrong alignments when __attribute__ ((optimize,target,align) is used

[ramana at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67745

--- Comment #5 from Ramana Radhakrishnan  ---
*** Bug 67880 has been marked as a duplicate of this bug. ***

[Bug target/67745] [ARM] wrong alignments when __attribute__ ((optimize,target,align) is used

[ramana at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67745

Ramana Radhakrishnan  changed:

   What|Removed |Added

 Status|UNCONFIRMED |ASSIGNED
   Last reconfirmed||2015-10-10
 CC||ramana at gcc dot gnu.org
   Assignee|unassigned at gcc dot gnu.org  |chrbr at gcc dot gnu.org
 Ever confirmed|0   |1

--- Comment #4 from Ramana Radhakrishnan  ---
Confirmed.

[Bug target/67745] [ARM] wrong alignments when __attribute__ ((optimize,target,align) is used

[chrbr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67745

chrbr at gcc dot gnu.org changed:

   What|Removed |Added

 Target||arm
   Target Milestone|--- |6.0

[Bug target/67745] [ARM] wrong alignments when __attribute__ ((optimize,target,align) is used

[chrbr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67745

--- Comment #1 from chrbr at gcc dot gnu.org ---
the problems are three folds:

- FUNCTION_BOUNDARY should not test optimize_size, that should be tested in
override_options_internal instead to be carried by
invoke_set_current_function_hook 

- FUNCTION_BOUNDARY depends on TARGET_THUMB that depends on the attribute
target. So it should be reevaluated at each function change, thus 
TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE

[Bug target/67745] [ARM] wrong alignments when __attribute__ ((optimize,target,align) is used

[chrbr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67745

--- Comment #2 from chrbr at gcc dot gnu.org ---
and test check optimize_function_for_speed_p (cfun)) in assemble_start_function
put an unnecessary constraint on align_functions (either from -falign-functions
or __attribute__).
We should be able to decrease alignment between functions for a target switch
in -Os, for example.

[Bug target/67745] [ARM] wrong alignments when __attribute__ ((optimize,target,align) is used

[chrbr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67745

--- Comment #3 from chrbr at gcc dot gnu.org ---
another example that gives suboptimal alignment:

void
__attribute__ ((optimize("Os")))
foo()
{
}

compiled with -O2 -mthumb is aligned on 2^2 instead of 2^1. -Os should remove
padding here.