[PATCH 01/27] S390: Fix handling of DXC-byte in FPC-register.

[Joseph Myers]

On Fri, 26 Jun 2015, Stefan Liebler wrote:

> On s390, the DXC(data-exception-code)-byte in FPC(floating-point-control)-
> register contains a code of the last occured exception.
> If bits 6 and 7 of DXC-byte are zero, the bits 0-5 correspond to the
> ieee-exception flag bits.
> The current implementation always uses these bits as ieee-exception flag bits.
> fetestexcept() reports any exception after the first usage of a
> vector-instruction in a process, because it raises an "vector instruction
> exception" with DXC-code 0xFE.
> This patch fixes the handling of the DXC-byte. The DXC-Byte is only handled
> if bits 6 and 7 are zero.

Was this issue user-visible in existing releases (for user programs using 
vector instructions)?  If so, please file the usual bug in Bugzilla, put 
the [BZ #N] notation in the ChangeLog entry, add to NEWS and close the bug 
when committing.

-- 
Joseph S. Myers
joseph@codesourcery.com