Re: [Qemu-devel] [PATCH] target-mips: Correct 32-bit address space wrapping

[Leon Alrae <leon.alrae@imgtec.com>]

On 05/12/2014 18:55, Maciej W. Rozycki wrote:
> On Thu, 4 Dec 2014, Leon Alrae wrote:
> 
>>> Index: qemu-git-trunk/target-mips/translate.c
>>> ===================================================================
>>> --- qemu-git-trunk.orig/target-mips/translate.c	2014-11-12 07:41:26.597542010 +0000
>>> +++ qemu-git-trunk/target-mips/translate.c	2014-11-12 07:41:26.597542010 +0000
>>> @@ -10724,6 +10724,7 @@ static void gen_mips16_save (DisasContex
>>>  {
>>>      TCGv t0 = tcg_temp_new();
>>>      TCGv t1 = tcg_temp_new();
>>> +    TCGv t2 = tcg_temp_new();
>>>      int args, astatic;
>>>  
>>>      switch (aregs) {
>>> @@ -10782,7 +10783,8 @@ static void gen_mips16_save (DisasContex
>>>      gen_load_gpr(t0, 29);
>>>  
>>>  #define DECR_AND_STORE(reg) do {                                 \
>>> -        tcg_gen_subi_tl(t0, t0, 4);                              \
>>> +        tcg_gen_movi_tl(t2, -4);                                 \
>>
>> Wouldn't it be better to move this line outside of the macro to avoid
>> generating unnecessary tcg ops? DECR_AND_STORE is called multiple times
>> and t2 doesn't change in-between.
> 
>  It would.  This code isn't wrong though unlike our current version, 
> this is merely a pessimisation.  An update will require a costly 
> regression test rerun and therefore I'll give the priority to the 
> outstanding changes I have before going back to this change.  Thanks for 
> the tip and your review.

Since above issue is minor we can correct it with incremental patch later.

I applied all the patches (excluding two patches touching machine.c)
which were sent prior to IEEE 754-2008 series to mips-next branch,
thanks. I'm intending to send out mips-next branch next week.

Regards,
Leon