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Re: [PATCH, GCC/ARM] Fix ICE when compiling empty FIQ interrupt handler in ARM mode
- From: Christophe Lyon <christophe dot lyon at linaro dot org>
- To: Kyrill Tkachov <kyrylo dot tkachov at foss dot arm dot com>
- Cc: Thomas Preudhomme <thomas dot preudhomme at foss dot arm dot com>, Ramana Radhakrishnan <ramana dot radhakrishnan at arm dot com>, Richard Earnshaw <richard dot earnshaw at arm dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 17 Nov 2016 14:36:20 +0100
- Subject: Re: [PATCH, GCC/ARM] Fix ICE when compiling empty FIQ interrupt handler in ARM mode
- Authentication-results: sourceware.org; auth=none
- References: <0ce9ef69-cf59-075e-d392-f5bed829c4d8@foss.arm.com> <582C2946.6030900@foss.arm.com>
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
Christophe