Re: [qemu-s390x] [Qemu-devel] [PATCH v1 11/15] s390x/tcg: Prepare for IEEE-inexact-exception control (XxC)

[Richard Henderson]

On 2/12/19 3:03 AM, David Hildenbrand wrote:
> Some instructions allow to suppress IEEE inexact exceptions.
> 
> z14 PoP, 9-23, "Suppression of Certain IEEE Exceptions"
>     IEEE-inexact-exception control (XxC): Bit 1 of
>     the M4 field is the XxC bit. If XxC is zero, recogni-
>     tion of IEEE-inexact exception is not suppressed;
>     if XxC is one, recognition of IEEE-inexact excep-
>     tion is suppressed.
> 
> Especially, handling for overflow/unerflow remains as is, inexact is
> reported along
> 
> z14 PoP, 9-23, "Suppression of Certain IEEE Exceptions"
>     For example, the IEEE-inexact-exception control (XxC)
>     has no effect on the DXC; that is, the DXC for IEEE-
>     overflow or IEEE-underflow exceptions along with the
>     detail for exact, inexact and truncated, or inexact and
>     incremented, is reported according to the actual con-
>     dition.
> 
> Follow up patches will wire it correctly up for the applicable
> instructions.
> 
> Signed-off-by: David Hildenbrand <address@hidden>
> ---
>  target/s390x/fpu_helper.c | 112 +++++++++++++++++++-------------------
>  1 file changed, 56 insertions(+), 56 deletions(-)

Reviewed-by: Richard Henderson <address@hidden>


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