Re: [PATCH 2/2] target/i386: Fix carry flag for BLSI

[Philippe Mathieu-Daudé]

On 1/8/24 09:58, Richard Henderson wrote:
> BLSI has inverted semantics for C as compared to the other two
> BMI1 instructions, BLSMSK and BLSR.  Introduce CC_OP_BLSI* for
> this purpose.

Fixes: 1d0b926150 ("target/i386: move scalar 0F 38 and 0F 3A instruction 
to new decoder")

or even older?

> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2175
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   target/i386/cpu.h                        |  5 +++++
>   target/i386/tcg/cc_helper.c              | 18 ++++++++++++++++++
>   target/i386/tcg/translate.c              |  5 +++++
>   tests/tcg/x86_64/test-2175.c             | 24 ++++++++++++++++++++++++
>   target/i386/tcg/cc_helper_template.h.inc | 18 ++++++++++++++++++
>   target/i386/tcg/emit.c.inc               |  2 +-
>   tests/tcg/x86_64/Makefile.target         |  1 +
>   7 files changed, 72 insertions(+), 1 deletion(-)
>   create mode 100644 tests/tcg/x86_64/test-2175.c


> +static int glue(compute_all_blsi, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
> +{
> +    int cf, pf, af, zf, sf, of;
> +
> +    cf = (src1 != 0);
> +    pf = 0; /* undefined */
> +    af = 0; /* undefined */
> +    zf = (dst == 0) * CC_Z;
> +    sf = lshift(dst, 8 - DATA_BITS) & CC_S;
> +    of = 0;
> +    return cf | pf | af | zf | sf | of;
> +}

Except this function which I'm not reviewing, for the rest
to the best of my x86 knowledge:
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>