This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[arm-embedded] [PATCH, GCC/ARM] Fix ICE when compiling empty FIQ interrupt handler in ARM mode


Hi,

We have decided to backport this patch to fix a testsuite failure in newly added test empty_fiq_handler to our embedded-6-branch.

*** gcc/testsuite/ChangeLog.arm ***

2016-11-21  Thomas Preud'homme  <thomas.preudhomme@arm.com>

        Backport to mainline
        2016-11-21  Thomas Preud'homme  <thomas.preudhomme@arm.com>

        * gcc.target/arm/empty_fiq_handler.c: Skip if -mthumb is passed in and
        target is Thumb-only.
--- Begin Message ---
On 17/11/16 20:04, Thomas Preudhomme wrote:
Hi Christophe,

On 17/11/16 13:36, Christophe Lyon wrote:
On 16 November 2016 at 10:39, Kyrill Tkachov
<kyrylo.tkachov@foss.arm.com> wrote:

On 09/11/16 16:19, Thomas Preudhomme wrote:

Hi,

This patch fixes the following ICE when building when compiling an empty
FIQ interrupt handler in ARM mode:

empty_fiq_handler.c:5:1: error: insn does not satisfy its constraints:
 }
 ^

(insn/f 13 12 14 (set (reg/f:SI 13 sp)
        (plus:SI (reg/f:SI 11 fp)
            (const_int 4 [0x4]))) irq.c:5 4 {*arm_addsi3}
     (expr_list:REG_CFA_ADJUST_CFA (set (reg/f:SI 13 sp)
            (plus:SI (reg/f:SI 11 fp)
                (const_int 4 [0x4])))
        (nil)))

The ICE was provoked by missing an alternative to reflect that ARM mode
can do an add of general register into sp which is unpredictable in Thumb
mode add immediate.

ChangeLog entries are as follow:

*** gcc/ChangeLog ***

2016-11-04  Thomas Preud'homme  <thomas.preudhomme@arm.com>

        * config/arm/arm.md (arm_addsi3): Add alternative for addition of
        general register with general register or ARM constant into SP
        register.


*** gcc/testsuite/ChangeLog ***

2016-11-04  Thomas Preud'homme  <thomas.preudhomme@arm.com>

        * gcc.target/arm/empty_fiq_handler.c: New test.


Testing: bootstrapped on ARMv7-A ARM mode & testsuite shows no regression.

Is this ok for trunk?


I see that "r" does not include the stack pointer (STACK_REG is separate
from GENERAL_REGs) so we are indeed missing
that constraint.

Ok for trunk.
Thanks,
Kyrill

Best regards,

Thomas



Hi Thomas,

The new test fails when compiled with -mthumb -march=armv5t:
gcc.target/arm/empty_fiq_handler.c: In function 'fiq_handler':
gcc.target/arm/empty_fiq_handler.c:11:1: error: interrupt Service
Routines cannot be coded in Thumb mode

Right, interrupt handler can only be compiled in the mode where the CPU boots.
So for non Thumb-only targets it should be compiled with -marm. I'll push a
patch tomorrow.

I've committed the following patch as obvious:

Interrupt handlers on ARM can only be compiled in the execution mode where the processor boot. That is -mthumb for Thumb-only devices, -marm otherwise. This changes the empty_fiq_handler to skip the test when -mthumb is passed but the processor boot in ARM mode.

ChangeLog entry is as follows:

*** gcc/testsuite/ChangeLog ***

2016-11-17  Thomas Preud'homme  <thomas.preudhomme@arm.com>

        * gcc.target/arm/empty_fiq_handler.c: Skip if -mthumb is passed in and
        target is Thumb-only.

Best regards,

Thomas
diff --git a/gcc/testsuite/gcc.target/arm/empty_fiq_handler.c b/gcc/testsuite/gcc.target/arm/empty_fiq_handler.c
index bbcfd0e32f9d0cc60c8a013fd1bb584b21aaad16..8313f2199122be153a737946e817a5e3bee60372 100644
--- a/gcc/testsuite/gcc.target/arm/empty_fiq_handler.c
+++ b/gcc/testsuite/gcc.target/arm/empty_fiq_handler.c
@@ -1,4 +1,5 @@
 /* { dg-do compile } */
+/* { dg-skip-if "" { ! arm_cortex_m } { "-mthumb" } } */
 
 /* Below code used to trigger an ICE due to missing constraints for
    sp = fp + cst pattern.  */

--- End Message ---

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]