Re: [Qemu-devel] [RFC] tcg/ppc: Do not overwrite lower address word on Darwin and AIX

["Andreas Färber" <andreas.faerber@web.de>]

Am 06.05.2012 22:01, schrieb malc:
> On Sun, 6 May 2012, Andreas F?rber wrote:
> 
>> For targets where TARGET_LONG_BITS != 32, i.e. 64-bit guests,
>> addr_reg is moved to r4. For hosts [without] TCG_TARGET_CALL_ALIGN_ARGS
>> either data_reg2 or data_reg or a masked version thereof would overwrite
>> r4. Place it in r5 instead, matching TCG_TARGET_CALL_ALIGN_ARGS hosts.
>>
>> This might explain crashes observed on Darwin/ppc but not on ppc64.
>>
>> Signed-off-by: Andreas F?rber <andreas.faerber@web.de>
>> ---
>>  tcg/ppc/tcg-target.c |    4 ----
>>  1 files changed, 0 insertions(+), 4 deletions(-)
>>
>> diff --git a/tcg/ppc/tcg-target.c b/tcg/ppc/tcg-target.c
>> index dc40716..4b85c89 100644
>> --- a/tcg/ppc/tcg-target.c
>> +++ b/tcg/ppc/tcg-target.c
>> @@ -816,11 +816,7 @@ static void tcg_out_qemu_st (TCGContext *s, const TCGArg *args, int opc)
>>  #else
>>      tcg_out_mov (s, TCG_TYPE_I32, 3, addr_reg2);
>>      tcg_out_mov (s, TCG_TYPE_I32, 4, addr_reg);
>> -#ifdef TCG_TARGET_CALL_ALIGN_ARGS
>>      ir = 5;
>> -#else
>> -    ir = 4;
>> -#endif
>>  #endif
>>  
>>      switch (opc) {
>>
> 
> Right you are.

Confirmed with qemu-system-x86_64 on Darwin/ppc - hangs without, works
with patch. Thanks for making me aware of that line of code. :)

I'll have a suggestion how to simplify your updated patch and will
resubmit fixed as [PATCH] series after testing. Hoping you can get a
non-Umlaut-broken version from Patchwork. ;)

Cheers,
Andreas