Re: [Qemu-devel] [PATCH RFC 1/2] tests/tcg: Allow targets to set the optimization level

[David Hildenbrand <david@redhat.com>]

On 27.02.19 12:46, Alex Bennée wrote:
> 
> David Hildenbrand <david@redhat.com> writes:
> 
>> We sometimes want basic optimizations, e.g. for constant propagation
>> into inlined functions.
>>
>> Especially for inline asm with immediates;
> 
> I agree you need this, but...
> 
> <snip>
>>  # Start with a blank slate, the build targets get to add stuff first
>> -CFLAGS=
>> +CFLAGS=-O0
>>  QEMU_CFLAGS=
>>  LDFLAGS=
>>
>> @@ -70,7 +70,7 @@ ifneq ($(TARGET_BASE_ARCH),$(TARGET_NAME))
>>  endif
>>
>>  # Add the common build options
>> -CFLAGS+=-Wall -O0 -g -fno-strict-aliasing
>> +CFLAGS+=-Wall -g -fno-strict-aliasing
> 
> 
> You don't need to do this - we already have EXTRA_CFLAGS which will
> always be at the end of the compile invocation:
> 
>   # enable vectors and optimisation to vectorise for this test
>   vglv: CFLAGS+=-march=z13 -m64
>   vglv: EXTRA_CFLAGS+=-O2

For whatever reason I can't get this to work. EXTRA_CFLAGS+=-O2 is
always silently dropped:

make SHELL='sh -x' run-tcg-tests-s390x-linux-user

+ /home/dhildenb/git/qemu/tests/docker/docker.py cc --user 100813 --cc
s390x-linux-gnu-gcc -i qemu:debian-s390x-cross -s
/home/dhildenb/git/qemu -- -march=zEC12 -m64 -Wall -O0 -g
-fno-strict-aliasing -march=z13
/home/dhildenb/git/qemu/tests/tcg/s390x/vlgv.c -o vlgv -static
/home/dhildenb/git/qemu/tests/tcg/s390x/vlgv.c: In function 'vlgv':
/home/dhildenb/git/qemu/tests/tcg/s390x/vlgv.c:8:5: warning: asm operand
3 probably doesn't match constraints
     asm volatile("vlgv %[r1], %[v3], 0(%[a2]), %[m4]\n"
     ^~~
/home/dhildenb/git/qemu/tests/tcg/s390x/vlgv.c:8:5: error: impossible
constraint in 'asm'



-- 

Thanks,

David / dhildenb