Re: [Qemu-trivial] [Qemu-devel] [PATCH] tci: Fix some unaligned memory accesses

[Stefan Weil]

On 09.04.19 08:58, Richard Henderson wrote:
> On 4/8/19 8:04 PM, Stefan Weil wrote:
>>  static tcg_target_ulong tci_read_i(uint8_t **tb_ptr)
>>  {
>> -    tcg_target_ulong value = *(tcg_target_ulong *)(*tb_ptr);
>> +    tcg_target_ulong value;
> 
> Ideally these would use the helpers from "qemu/bswap.h", ldl_he_p(), etc.
> 
> r~



That would require adding a helper for tcg_target_ulong to qemu/bswap.h.
Or tci.c would need conditional code for reading a tcg_target_ulong.

Those helpers in qemu/bswap.h are also a little bit strange:

- Why does lduw_he_p return an int instead of an uint16_t?
- Why does ldsw_he_p return an int instead of an int16_t?
- Why does ldl_he_p return an int instead of an int32_t?
- Should ldl_he_p be renamed into ldsl_he_p?
  And why is ldul_he_p missing?
- Should ldq_he_p be renamed into lduq_he_p?
  And why is ldsq_he_p missing?

Using the helpers might require nasty type casts to avoid compiler
warnings because of signed / unsigned and size mismatches.

Aren't the few memcpy statements in the TCI helpers much more direct and
understandable?

Regards
Stefan