[Qemu-devel] Re: [PATCH] cpu-all.h: Remove unnecessary target-specific ifdef for CPU_QuadU

[Peter Maydell]

On 4 April 2011 15:47, Alexander Graf <address@hidden> wrote:
> On 04/04/2011 01:09 PM, Peter Maydell wrote:
>>
>> CPU_QuadU isn't used on all targets, but there's no harm in defining the
>> typedef anyway. It only needs to be guarded by CONFIG_SOFTFLOAT, because
>> softfloat-native doesn't have a float128 type. This avoids the need for
>> every new target which uses CPU_QuadU to add itself to an #ifdef in
>> what ought to be target-agnostic code.
>>
>> Signed-off-by: Peter Maydell<address@hidden>
>
> I don't really know my way around FP, but from here it looks good :). Not
> sure about the arm part, but I trust Peter on that one ;).

The __arm__ part of the ifdef was a voodoo-copy from the CPU_DoubleU
typedef, where it actually does matter if you're building a softfloat-native
target on an ARM host which uses the ancient FPA floating point ABI
(as the comment says, although ARM is generally little-endian doubles
are stored in memory in big-endian order under FPA; the more modern
VFP has them little-endian). This ifdef condition was meaningless for
CPU_QuadU (because FPA didn't have a 128 bit native float type for the
type to try to be compatible with) and could never have kicked in
anyhow because we wouldn't have compiled unless CONFIG_SOFTFLOAT
was defined.

-- PMM