Re: [Qemu-devel] [Qemu-ppc] [PATCH 2/3] target-ppc : Add PPC_FLOAT_64 flag to instructions type

[Tom Musta <tommusta@gmail.com>]

On 9/10/2014 4:18 AM, Alexander Graf wrote:
> 
> 
> On 10.09.14 07:03, Pierre Mallard wrote:
>> This patch declare a new floating point instruction flag PPC_FLOAT_64 to be used
>> by fcfid, fctid[z] operations. Note that due to limited number of bit, 
>> FSEL and FRES points now to same value, and PPC_FLOAT_64 to former FSEL value. 
>> (There seems to be no case where FSEL and FRES are not used together at the moment)
>>
>> Signed-off-by: Pierre Mallard <mallard.pierre@gmail.com>
>> ---
>>  target-ppc/cpu.h            |    7 +++++--
>>  target-ppc/translate_init.c |    2 +-
>>  2 files changed, 6 insertions(+), 3 deletions(-)
>>
>> diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
>> index b64c652..b5b3912 100644
>> --- a/target-ppc/cpu.h
>> +++ b/target-ppc/cpu.h
>> @@ -1868,9 +1868,12 @@ enum {
>>      PPC_FLOAT_FRES     = 0x0000000000080000ULL,
>>      PPC_FLOAT_FRSQRTE  = 0x0000000000100000ULL,
>>      PPC_FLOAT_FRSQRTES = 0x0000000000200000ULL,
>> -    PPC_FLOAT_FSEL     = 0x0000000000400000ULL,
>> +    PPC_FLOAT_FSEL     = 0x0000000000080000ULL,
>>      PPC_FLOAT_STFIWX   = 0x0000000000800000ULL,
>>  
>> +    /* Use for PPC with double precision fpu */
>> +    PPC_FLOAT_64   = 0x0000000000400000ULL,
> 
> Please keep the list sorted by the bit number. Also I think we're better
> off not having the same bit used for 2 enums. Just keep PPC_FLOAT_FRES
> and make FSEL depend on the FRES bit in translate.c
> 

Alternatively, you could add the new flag to PPC2_xxx .

>> +
>>      /* Vector/SIMD extensions                                                */
>>      /*   Altivec support                                                     */
>>      PPC_ALTIVEC        = 0x0000000001000000ULL,
>> @@ -1957,7 +1960,7 @@ enum {
>>                          | PPC_STRING | PPC_FLOAT | PPC_FLOAT_EXT \
>>                          | PPC_FLOAT_FSQRT | PPC_FLOAT_FRES \
>>                          | PPC_FLOAT_FRSQRTE | PPC_FLOAT_FRSQRTES \
>> -                        | PPC_FLOAT_FSEL | PPC_FLOAT_STFIWX \
>> +                        | PPC_FLOAT_FSEL | PPC_FLOAT_STFIWX | PPC_FLOAT_64 \
>>                          | PPC_ALTIVEC | PPC_SPE | PPC_SPE_SINGLE \
>>                          | PPC_SPE_DOUBLE | PPC_MEM_TLBIA \
>>                          | PPC_MEM_TLBIE | PPC_MEM_TLBSYNC \
>> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
>> index b4dedce..073bef1 100644
>> --- a/target-ppc/translate_init.c
>> +++ b/target-ppc/translate_init.c
>> @@ -3899,7 +3899,7 @@ POWERPC_FAMILY(440x5)(ObjectClass *oc, void *data)
>>      pcc->insns_flags = PPC_INSNS_BASE | PPC_STRING |
>>  #ifdef PPC440x5_HAVE_FPU
>>                         PPC_FLOAT | PPC_FLOAT_FSQRT | 
>> -                       PPC_FLOAT_STFIWX |
>> +                       PPC_FLOAT_STFIWX | PPC_FLOAT_64 |
>>  #endif
>>                         PPC_DCR | PPC_WRTEE | PPC_RFMCI |
>>                         PPC_CACHE | PPC_CACHE_ICBI |
>>