Re: [PATCH v2 for-10.0 37/54] target/i386: Set default NaN pattern explicitly

[Richard Henderson]

On 12/2/24 07:13, Peter Maydell wrote:
> Set the default NaN pattern explicitly, and remove the ifdef from
> parts64_default_nan().
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   target/i386/tcg/fpu_helper.c   | 4 ++++
>   fpu/softfloat-specialize.c.inc | 3 ---
>   2 files changed, 4 insertions(+), 3 deletions(-)

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

r~

> diff --git a/target/i386/tcg/fpu_helper.c b/target/i386/tcg/fpu_helper.c
> index c8bc5b7cfb3..e788fcd1b25 100644
> --- a/target/i386/tcg/fpu_helper.c
> +++ b/target/i386/tcg/fpu_helper.c
> @@ -181,6 +181,10 @@ void cpu_init_fp_statuses(CPUX86State *env)
>        */
>       set_float_infzeronan_rule(float_infzeronan_dnan_never, &env->sse_status);
>       set_float_3nan_prop_rule(float_3nan_prop_abc, &env->sse_status);
> +    /* Default NaN: sign bit set, most significant frac bit set */
> +    set_float_default_nan_pattern(0b11000000, &env->fp_status);
> +    set_float_default_nan_pattern(0b11000000, &env->mmx_status);
> +    set_float_default_nan_pattern(0b11000000, &env->sse_status);
>   }
>   
>   static inline uint8_t save_exception_flags(CPUX86State *env)
> diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc
> index d77404f0c47..452fe378cd2 100644
> --- a/fpu/softfloat-specialize.c.inc
> +++ b/fpu/softfloat-specialize.c.inc
> @@ -139,9 +139,6 @@ static void parts64_default_nan(FloatParts64 *p, 
> float_status *status)
>   #if defined(TARGET_SPARC) || defined(TARGET_M68K)
>           /* Sign bit clear, all frac bits set */
>           dnan_pattern = 0b01111111;
> -#elif defined(TARGET_I386) || defined(TARGET_X86_64)
> -        /* Sign bit set, most significant frac bit set */
> -        dnan_pattern = 0b11000000;
>   #elif defined(TARGET_HPPA)
>           /* Sign bit clear, msb-1 frac bit set */
>           dnan_pattern = 0b00100000;