Re: [Qemu-devel] [V4 PATCH 04/22] softfloat: Fix float64_to_uint32

[Peter Maydell <peter.maydell@linaro.org>]

On 18 December 2013 20:19, Tom Musta <tommusta@gmail.com> wrote:
> The float64_to_uint32 has several flaws:
>
>  - for numbers between 2**32 and 2**64, the inexact exception flag
>    may get incorrectly set.  In this case, only the invalid flag
>    should be set.
>
>        test pattern: 425F81378DC0CD1F / 0x1.f81378dc0cd1fp+38
>
>  - for numbers between 2**63 and 2**64, incorrect results may
>    be produced:
>
>        test pattern: 43EAAF73F1F0B8BD / 0x1.aaf73f1f0b8bdp+63
>
> This patch re-implements float64_to_uint32 to re-use the
> float64_to_uint64 routine (instead of float64_to_int64).  For the
> saturation case, the inexact bit is explicitly cleared before raising
> the invalid flag, provided that it was not previously set.
>
> V4: Fixed handling of stickiness of the inexact bit per comments from
> Peter Maydell.
>
> This contribution can be licensed under either the softfloat-2a or -2b
> license.
>
> Signed-off-by: Tom Musta <tommusta@gmail.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

(though you might tidy up the commit message as per other
email).

I have a patch which fixes the remaining float-to-int conversion
functions (ie the ones you didn't deal with in this series) to not
raise Inexact when they raise Invalid for out of range, and one
which fixes a bug in scalbn. I'll send those out shortly.

thanks
-- PMM