Re: [PATCH v3 06/14] tcg/{i386,s390x}: Add earlyclobber to the op_add2's first output

[Richard Henderson]

On 7/19/23 23:11, Ilya Leoshkevich wrote:
> i386 and s390x implementations of op_add2 require an earlyclobber,
> which is currently missing. This breaks VCKSM in s390x guests. E.g., on
> x86_64 the following op:
>
>      add2_i32 tmp2,tmp3,tmp2,tmp3,tmp3,tmp2   dead: 0 2 3 4 5  pref=none,0xffff
>
> is translated to:
>
>      addl     %ebx, %r12d
>      adcl     %r12d, %ebx
>
> Introduce a new C_N1_O1_I4 constraint, and make sure that earlyclobber
> of aliased outputs is honored.
>
> Cc:qemu-stable@nongnu.org
> Fixes: 82790a870992 ("tcg: Add markup for output requires new register")
> Signed-off-by: Ilya Leoshkevich<iii@linux.ibm.com>
> ---
>   tcg/i386/tcg-target-con-set.h  | 5 ++++-
>   tcg/i386/tcg-target.c.inc      | 2 +-
>   tcg/s390x/tcg-target-con-set.h | 8 +++++---
>   tcg/s390x/tcg-target.c.inc     | 4 ++--
>   tcg/tcg.c                      | 8 +++++++-
>   5 files changed, 19 insertions(+), 8 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~