Re: [Qemu-devel] [PATCH 1/2] tcg: Add TYPE parameter to tcg_out_mov.

[Richard Henderson <rth@twiddle.net>]

On 05/28/2010 11:21 AM, Aurelien Jarno wrote:
>> +        tcg_out_mov(s, TCG_TYPE_PTR, data_reg, arg0);
> 
> Is it something correct? This refers to a data register according to the
> name of the variable.
> 
>>          break;
>>      }
>>  
>> @@ -1007,10 +1007,10 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
>>      tcg_out32(s, 0);
>>  
>>      /* mov (delay slot) */
>> -    tcg_out_mov(s, arg0, addr_reg);
>> +    tcg_out_mov(s, TCG_TYPE_PTR, arg0, addr_reg);
> 
> Here this looks correct
> 
>>      /* mov */
>> -    tcg_out_mov(s, arg1, data_reg);
>> +    tcg_out_mov(s, TCG_TYPE_PTR, arg1, data_reg);
> 
> Here not.
> 
> I am also a bit puzzled that TCG_TYPE_PTR only appears on the sparc
> target, though I haven't looked at the code, it might be normal.

Most targets I didn't bother to figure out whether the item is or isn't a pointer.
I.e. on arm/hppa/ppc/mips targets I simply always used _I32, and on ppc64 target I 
always used _I64.

Sparc is, at present, the only target that supports multiple register sizes.
The only TCG_TYPE_FOO we have that corresponds to the current register size
is TCG_TYPE_PTR; there isn't a TCG_TYPE_REG or whatever that documents that
we want to move an object of the native register size.

Not that it *really* matters for sparc, since there is one common move insn
for both 32-bit and 64-bit mode, but I thought _PTR was slightly more correct
than using either _I32 or _I64.


r~