Re: openbios fails to build with gcc-16 (powerpc code)

Michael Tokarev <[email protected]>
Newsgroups org.nongnu.qemu-devel
Message-ID <[email protected]>
On 8/6/26 15:23, Michael Tokarev wrote:
> On 8/6/26 12:56, Michael Tokarev wrote:
>> Hi!
>>
>> Since debian switch from gcc-15 to gcc-16, qemu fails to build openbios-powerpc:
>>
>> powerpc-linux-gnu-gcc -m32 -mcpu=604 ...\
>>   roms/openbios/arch/ppc/qemu/start.S
>>
>> roms/openbios/arch/ppc/qemu/start.S:292: Error: unrecognized opcode: `clrldi'
>> roms/openbios/arch/ppc/qemu/start.S:293: Error: unrecognized opcode: `mtmsrd'
>> roms/openbios/arch/ppc/qemu/start.S:178: Error: unrecognized opcode: `std'
>> [a lot of other similar errors]
>>
>> I know nothing about powerpc assembler.  Google tells me mtmsrd is a 64bit-only
>> instruction which can't be used in 32bit mode (which is in effect here).
>>
>> It feels like start.S uses the wrong assembly?  I wonder how it worked before..
> 
> The issue boils down to missing -many option to as when using gcc-16.
> With gcc-15, as is being run with
>    -a32 -mppc -many -mbig
> but gcc-16 omits -many:
>    -a32 -mppc -mbig
> Explicitly adding -Wa,-many lets the build to proceed.

This seems to be a debian bug or gcc bug which is fixed in a later version
(unfortunately searching for the term "many" isn't giving good results) --
https://bugs.debian.org/1143807

/mjt
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