[Bug rtl-optimization/64616] Redundant ldr when accessing var inside and outside a loop

[thopre01 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64616

Thomas Preud'homme  changed:

   What|Removed |Added

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

--- Comment #6 from Thomas Preud'homme  ---
(In reply to Martin Liška from comment #5)
> Can the bug be marked as resolved?

Yes, fixed in GCC 6 onward.

[Bug rtl-optimization/64616] Redundant ldr when accessing var inside and outside a loop

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64616

Martin Liška  changed:

   What|Removed |Added

 CC||marxin at gcc dot gnu.org

--- Comment #5 from Martin Liška  ---
Can the bug be marked as resolved?

[Bug rtl-optimization/64616] Redundant ldr when accessing var inside and outside a loop

[thopre01 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64616

--- Comment #4 from Thomas Preud'homme thopre01 at gcc dot gnu.org ---
Author: thopre01
Date: Wed May 13 05:39:14 2015
New Revision: 223113

URL: https://gcc.gnu.org/viewcvs?rev=223113root=gccview=rev
Log:
2015-05-13  Thomas Preud'homme  thomas.preudho...@arm.com

gcc/
PR rtl-optimization/64616
* loop-invariant.c (can_move_invariant_reg): New.
(move_invariant_reg): Call above new function to decide whether
instruction can just be moved, skipping creation of temporary
register.

gcc/testsuite/
PR rtl-optimization/64616
* gcc.dg/loop-8.c: New test.
* gcc.dg/loop-9.c: New test.

Added:
trunk/gcc/testsuite/gcc.dg/loop-8.c
trunk/gcc/testsuite/gcc.dg/loop-9.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/loop-invariant.c
trunk/gcc/testsuite/ChangeLog

[Bug rtl-optimization/64616] Redundant ldr when accessing var inside and outside a loop

[thopre01 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64616

--- Comment #3 from Thomas Preud'homme thopre01 at gcc dot gnu.org ---
*** Bug 64458 has been marked as a duplicate of this bug. ***

[Bug rtl-optimization/64616] Redundant ldr when accessing var inside and outside a loop

[thopre01 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64616

thopre01 at gcc dot gnu.org changed:

   What|Removed |Added

 Status|UNCONFIRMED |ASSIGNED
   Last reconfirmed||2015-01-16
   Assignee|unassigned at gcc dot gnu.org  |thopre01 at gcc dot 
gnu.org
 Ever confirmed|0   |1

[Bug rtl-optimization/64616] Redundant ldr when accessing var inside and outside a loop

[thopre01 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64616

thopre01 at gcc dot gnu.org changed:

   What|Removed |Added

 Target||arm-none-eabi

--- Comment #1 from thopre01 at gcc dot gnu.org ---
At least with -mcpu=cortex-m3 and -mthumb. I haven't tried other combinations
yet.

[Bug rtl-optimization/64616] Redundant ldr when accessing var inside and outside a loop

[thopre01 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64616

--- Comment #2 from thopre01 at gcc dot gnu.org ---
For arm-none-linux-gnueabihf-gcc configured with --with-arch=armv7-a and
compiling without any -mcpu (so default cpu) the problem is also there:

stmfd   sp!, {r4, r5, r6, lr}
movwr5, #:lower16:glob
movtr5, #:upper16:glob
.L2:
ldr r0, [r5]
movwr4, #:lower16:glob
bl  g
movtr4, #:upper16:glob
cmp r0, #0
bne .L2
mov r3, #1
str r3, [r4]
ldmfd   sp!, {r4, r5, r6, pc}

This is due to pre introducing a new pseudoregister to load the address of glob
and cprop propagating it only locally in the same basic block but not globally
into the store.