Re: [Qemu-devel] [PATCH v3 00/15] s390x/tcg: Implement floating-point extension facility

[Cornelia Huck <cohuck@redhat.com>]

On Mon, 18 Feb 2019 13:26:55 +0100
David Hildenbrand <david@redhat.com> wrote:

> This series is based on the patches currently on the list:
> - [PATCH v2] softfloat: add float128_is_{normal,denormal}​
> - [PATCH v1] softfloat: Implement float128_to_uint32
> - [PATCH v2] softfloat: Support float_round_to_odd more places
> 
> For the KVM folks, only the last patch is of interest.
> 
> The floating-point extension facility seems to be used often without
> checking by user space. Vector instruction support seems to somewhat also
> rely on it being available. Some parts are already implemented, others
> not or are broken.
> 
> Fix some stuff in fpu code, add some FIXMEs to indicate what is definetly
> missing and implement all BFP stuff needed for the floating-point extension
> facility. Finally, enable it for TCG, adding it to the CPU model for the
> 4.0 compat machine.
> 
> This series also contains some refactorings needed for floating-point
> vector instruction support.
> 
> v2 -> v3:
> - "s390x/tcg: Implement XxC and checks for most FP instructions"
> -- Use extract32() with constant arithmetic
> - Use float_round_to_odd and get rid of the corresponding FIXMEs. Thanks
>   Richard!
> 
> v1 -> v2:
> - "s390x/tcg: Fix TEST DATA CLASS instructions"
> -- Simplify + use marko
> - "s390x/tcg: Prepare for IEEE-inexact-exception control (XxC)"
> -- Fix some whitespace/newline issues
> - "s390x/tcg: Handle SET FPC AND LOAD FPC 3-bit BFP rounding modes"
> -- If FPE is not installed, also bail out on 3rd BFP bit
> - "s390x/tcg: Implement XxC and checks for most FP instructions"
> -- Use helper functions to simplify checks+mangling+unmangling
> -- Take care of FPE facility state
> -- Fix that XxC is actually bit 1, not bit 0
> - "s390x/tcg: Prepare for IEEE-inexact-exception control (XxC)"
> -- Also use new helper functions
> 
> David Hildenbrand (15):
>   s390x/tcg: Fix TEST DATA CLASS instructions
>   s390x/tcg: Fix rounding from float128 to uint64_t/uin32_t
>   s390x/tcg: Factor out conversion of softfloat exceptions
>   s390x/tcg: Fix parts of IEEE exception handling
>   s390x/tcg: Hide IEEE underflows in some scenarios
>   s390x/tcg: Refactor SET FPC AND SIGNAL handling
>   s390x/tcg: Fix simulated-IEEE exceptions
>   s390x/tcg: Handle SET FPC AND LOAD FPC 3-bit BFP rounding modes
>   s390x/tcg: Check for exceptions in SET BFP ROUNDING MODE
>   s390x/tcg: Refactor saving/restoring the bfp rounding mode
>   s390x/tcg: Prepare for IEEE-inexact-exception control (XxC)
>   s390x/tcg: Implement XxC and checks for most FP instructions
>   s390x/tcg: Implement rounding mode and XxC for LOAD ROUNDED
>   s390x/tcg: Handle all rounding modes overwritten by BFP instructions
>   s390x: Add floating-point extension facility to "qemu" cpu model
> 
>  target/s390x/fpu_helper.c   | 541 ++++++++++++++++++++++--------------
>  target/s390x/gen-features.c |   5 +
>  target/s390x/helper.h       |   9 +-
>  target/s390x/insn-data.def  |  12 +-
>  target/s390x/internal.h     |   9 +
>  target/s390x/translate.c    | 315 ++++++++++++++-------
>  6 files changed, 572 insertions(+), 319 deletions(-)
> 

Does anyone still want to give a R-b (especially for the patches that
don't have one yet?) I plan to queue this once the softfloat patches
hit master.