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From: Blue Swirl <blauwirbel@gmail.com>
Date: Fri, 6 May 2011 18:30:12 +0300
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Subject: Re: [Qemu-devel] [PATCH 4/7] target-arm: Refactor int-float
	conversions
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To: Paul Brook <paul@codesourcery.com>
Cc: Peter Maydell <peter.maydell@linaro.org>, qemu-devel@nongnu.org, patches@linaro.org

On Fri, May 6, 2011 at 5:09 PM, Paul Brook <paul@codesourcery.com> wrote:
>> The Neon versions of int-float conversions need their own helper routine=
s
>> because they must use the "standard FPSCR" rather than the default one.
>> Refactor the helper functions to make it easy to add the neon versions.
>> While we're touching the code, move the helpers to op_helper.c so that
>> we can use the global env variable rather than passing it as a parameter=
.
>
> IMO this is going in the wrong direction. =C2=A0We should in aiming for l=
ess
> implicit accesses to cpu state, not more.

Performance wise global env variable is faster and the register is
always available. Do you mean that we should aim to get rid of special
status of global env, so that if no op uses it, it could be discarded
to free a register?

> Maybe better would be to explicitly pass a pointer the fp status. That wa=
y you
> don't even need separate VFP and NEON variants of these routines.

It would be nice to have generic float functions callable directly as
TCG helper.