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Date: Fri, 28 Feb 2014 13:28:03 -0600
From: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
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Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH v4] target-ppc: gdbstub allow
 byte swapping for reading/writing registers
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To: Richard Henderson <rth@twiddle.net>, qemu-devel@nongnu.org
Cc: qemu-ppc@nongnu.org

On 02/28/2014 11:37 AM, Richard Henderson wrote:
> On 02/26/2014 02:51 PM, Thomas Falcon wrote:
>> +void ppc_cpu_gdb_swap_register(uint8_t *mem_buf, int n)
>> +{
>> +    int len = ppc_cpu_gdb_register_len(n);
>> +    int i = 0;
>> +    uint8_t tmp;
>> +    for (i = 0; i < len/2; i++) {
>> +        tmp = *(mem_buf + i);
>> +        *(mem_buf+i) = *(mem_buf + len - 1 - i);
>> +        *(mem_buf + len - 1 - i) = tmp;
>> +    }
>> +}
> Ew.
>
> The number of register sizes you need to handle is extremely limited.  One can
> easily use bswap32 and bswap64 for this.
>
>
> r~
>
Thanks for your feedback.  Did not realize there were built-in bswap 
functions for pointers.  How about this instead?

int len = ppc_cpu_gdb_register_len(n);
if (len==4) {
     bswap32s((uint32_t *)mem_buf);
} else {
     bswap64s((uint64_t *)mem_buf);
}