Re: [PATCH] tests/tcg: Replace -mpower8-vector with -mvsx

[Richard Henderson <richard.henderson@linaro.org>]

On 10/23/24 05:17, Ilya Leoshkevich wrote:
> On Mon, 2024-10-21 at 19:59 -0700, Richard Henderson wrote:
>> On 10/21/24 07:27, Ilya Leoshkevich wrote:
>>> [1] deprecated -mpower8-vector, resulting in:
>>>
>>>       powerpc64-linux-gnu-gcc: warning: switch '-mpower8-vector' is
>>> no longer supported
>>>       qemu/tests/tcg/ppc64/vsx_f2i_nan.c:4:15: error: expected ';'
>>> before 'float'
>>>           4 | typedef vector float vsx_float32_vec_t;
>>>             |               ^~~~~~
>>>
>>> Similar to how this was done for the GCC testcases, replace
>>> -mpower8-vector with -mvsx.
>>>
>>> [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109987
>>>
>>> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
>>> ---
>>>    tests/tcg/ppc64/Makefile.target | 10 +++++-----
>>>    1 file changed, 5 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/tests/tcg/ppc64/Makefile.target
>>> b/tests/tcg/ppc64/Makefile.target
>>> index 1940886c737..d1b00d2bf09 100644
>>> --- a/tests/tcg/ppc64/Makefile.target
>>> +++ b/tests/tcg/ppc64/Makefile.target
>>> @@ -6,7 +6,7 @@ VPATH += $(SRC_PATH)/tests/tcg/ppc64
>>>    
>>>    config-cc.mak: Makefile
>>>    	$(quiet-@)( \
>>> -	    $(call cc-option,-mpower8-vector,
>>> CROSS_CC_HAS_POWER8_VECTOR); \
>>> +	    $(call cc-option,-mvsx,             CROSS_CC_HAS_VSX);
>>> \
>>>    	    $(call cc-option,-mpower10,
>>> CROSS_CC_HAS_POWER10)) 3> config-cc.mak
>>
>> I don't think this is quite right.
>> I think you need -mpower8 to get OPTION_MASK_P8_VECTOR set.
> 
> Do you mean -mcpu=power8? -mpower8 is a GAS option.

It looks like I do, yes.
Also in that vein, -mpower10 has been marked WarnRemoved in gcc trunk.


> I was confused why -mvsx works in practice, so I spent some time and
> managed to create a "hostile" gcc build, in which this is now a
> problem, using:
> 
>      ./configure --target=powerpc64-linux-gnu --enable-checking \
>                  --disable-bootstrap \
>                  --with-as="$(which powerpc64-linux-gnu-as)"
> 
> The issue is masked by two things:
> 
> - GCC passes "-many" to GAS. GCC commit e154242724b0 ("[RS6000] Don't
>    pass -many to the assembler") stops --enable-checking builds from
>    doing this.
> 
> - binutils has the following line:
> 
>    /* The minimum supported cpu for 64-bit little-endian is power8.  */
>    ppc_cpu |= ppc_parse_cpu (ppc_cpu, &sticky, "power8");
> 
>    so one needs to use the big-endian toolchain to see the problem.

Ah hah!  Good sleuthing.


r~