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From: Alex =?utf-8?Q?Benn=C3=A9e?= <alex.bennee@linaro.org>
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Date: Wed, 04 Jun 2014 12:11:36 +0100
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Subject: Re: [Qemu-devel] [RCF PATCH 5/8] arm/nwfps: remove use of
	cpsr_write() and set flags directly
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To: Peter Maydell <peter.maydell@linaro.org>
Cc: Edgar Iglesias <edgar.iglesias@xilinx.com>, Riku Voipio <riku.voipio@iki.fi>, QEMU Developers <qemu-devel@nongnu.org>, Greg Bellows <greg.bellows@linaro.org>


Peter Maydell writes:

> On 2 June 2014 17:21, Alex Bennée <alex.bennee@linaro.org> wrote:
>> This is a pre-cursor to removing the cpsr_write function.
>>
>> diff --git a/linux-user/arm/nwfpe/fpa11.h b/linux-user/arm/nwfpe/fpa11.h
>> index bb9ac65..0dbdf75 100644
>> --- a/linux-user/arm/nwfpe/fpa11.h
>> +++ b/linux-user/arm/nwfpe/fpa11.h
>> @@ -108,7 +108,10 @@ static inline void writeRegister(unsigned int x, unsigned int y)
>>
>>  static inline void writeConditionCodes(unsigned int x)
>>  {
>> -        cpsr_write(user_registers,x,CPSR_NZCV);
>> +        user_registers->ZF = (~val) & CPSR_Z;
>> +        user_registers->NF = val;
>> +        user_registers->CF = (val >> 29) & 1;
>> +        user_registers->VF = (val << 3) & 0x80000000;
>>  }
>>
>>  #define ARM_REG_PC 15
>
> This seems like it's clearly making things worse.
> We definitely don't want to have to have code in
> linux-user be aware of the "interesting" definitions
> of our ZF/NF/CF/VF fields.
<snip>

You are right. I could make restore_state_from_spsr use a mask like the
old cpsr_write did or as the flags are a special case have a flag only
setting function for these cases.

-- 
Alex Bennée