[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v3 05/20] tcg-arm: Handle constant arguments to
From: |
Richard Henderson |
Subject: |
Re: [Qemu-devel] [PATCH v3 05/20] tcg-arm: Handle constant arguments to add2/sub2 |
Date: |
Thu, 28 Mar 2013 09:04:01 -0700 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 |
On 03/28/2013 08:56 AM, Peter Maydell wrote:
>> +#define TO_CPSR (1 << 20)
>
> This is the S bit; I think it would be helpful if our #define
> had a name that made that clearer...
Suggestions? I thought "TO_CPSR" was clear...
>> + ARITH_TST = 0x8 << 21 | TO_CPSR,
>> + ARITH_CMP = 0xa << 21 | TO_CPSR,
>> + ARITH_CMN = 0xb << 21 | TO_CPSR,
>> + ARITH_ORR = 0xc << 21,
>> + ARITH_MOV = 0xd << 21,
>> + ARITH_BIC = 0xe << 21,
>> + ARITH_MVN = 0xf << 21,
>> };
>
> It feels a little ugly to OR in the S bit in this enum, but I guess
> it works.
I think it actually makes everything a lot cleaner myself. Especially given
the previous definition that required runtime checks for TST et al.
> Maybe we should add ARITH_TEQ at some point?
Given that it's the only one left out, sure. I can't imagine what context it
would be useful within tcg though -- it's main use seems to be doing an
equality comparison while preserving the C flag.
r~
[Qemu-devel] [PATCH v3 03/20] tcg-arm: Allow constant first argument to sub, Richard Henderson, 2013/03/28
[Qemu-devel] [PATCH v3 06/20] tcg-arm: Improve constant generation, Richard Henderson, 2013/03/28
[Qemu-devel] [PATCH v3 07/20] tcg-arm: Fold epilogue into INDEX_op_exit_tb, Richard Henderson, 2013/03/28
[Qemu-devel] [PATCH v3 08/20] tcg-arm: Implement deposit for armv7, Richard Henderson, 2013/03/28