Re: [Qemu-devel] [PATCH v5 27/28] fpu/softfloat: Clean up parts_default_nan

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <richard.henderson@linaro.org> writes:

> Reduce the number of ifdefs.  Correct the result for OpenRISC
> and TriCore (although TriCore fixed in target-specific code).
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>  fpu/softfloat-specialize.h | 21 ++++++++++++++-------
>  1 file changed, 14 insertions(+), 7 deletions(-)
>
> diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
> index 9d562ed504..ec4fb6ba8b 100644
> --- a/fpu/softfloat-specialize.h
> +++ b/fpu/softfloat-specialize.h
> @@ -129,22 +129,29 @@ static FloatParts parts_default_nan(float_status *status)
>      uint64_t frac;
>
>  #if defined(TARGET_SPARC) || defined(TARGET_M68K)
> +    /* !snan_bit_is_one, set all bits */
>      frac = (1ULL << DECOMPOSED_BINARY_POINT) - 1;
> -#elif defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_ALPHA) || \
> -      defined(TARGET_S390X) || defined(TARGET_RISCV)
> +#elif defined(TARGET_I386) || defined(TARGET_X86_64) \
> +    || defined(TARGET_MICROBLAZE)
> +    /* !snan_bit_is_one, set sign and msb */
>      frac = 1ULL << (DECOMPOSED_BINARY_POINT - 1);
> +    sign = 1;
>  #elif defined(TARGET_HPPA)
> +    /* snan_bit_is_one, set msb-1.  */
>      frac = 1ULL << (DECOMPOSED_BINARY_POINT - 2);
>  #else
> +    /* This case is true for Alpha, ARM, MIPS, OpenRISC, PPC, RISC-V,
> +     * S390, SH4, TriCore, and Xtensa.  I cannot find documentation
> +     * for Unicore32; the choice from the original commit is unchanged.
> +     * Our other supported targets, CRIS, LM32, Moxie, Nios2, and Tile,
> +     * do not have floating-point.
> +     */
>      if (snan_bit_is_one(status)) {
> +        /* set all bits other than msb */
>          frac = (1ULL << (DECOMPOSED_BINARY_POINT - 1)) - 1;
>      } else {
> -#if defined(TARGET_MIPS)
> +        /* set msb */
>          frac = 1ULL << (DECOMPOSED_BINARY_POINT - 1);
> -#else
> -        frac = 1ULL << (DECOMPOSED_BINARY_POINT - 1);
> -        sign = 1;
> -#endif
>      }
>  #endif


--
Alex Bennée