Re: [Qemu-devel] [PATCH v2 1/7] target-ppc: Implement bcd_is_valid function

[David Gibson <david@gibson.dropbear.id.au>]

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On Tue, Dec 06, 2016 at 05:40:04PM -0200, Jose Ricardo Ziviani wrote:
> A function to check if all digits of a given BCD number is valid is
> here presented because more instructions will need to reuse the
> same code.
> 
> Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>

I've applied this patch to ppc-for-2.9, the rest still have comments
on them.

> ---
>  target-ppc/int_helper.c | 27 ++++++++++++++++++++-------
>  1 file changed, 20 insertions(+), 7 deletions(-)
> 
> diff --git a/target-ppc/int_helper.c b/target-ppc/int_helper.c
> index 7030f61..7989b1f 100644
> --- a/target-ppc/int_helper.c
> +++ b/target-ppc/int_helper.c
> @@ -2596,6 +2596,24 @@ static void bcd_put_digit(ppc_avr_t *bcd, uint8_t digit, int n)
>      }
>  }
>  
> +static bool bcd_is_valid(ppc_avr_t *bcd)
> +{
> +    int i;
> +    int invalid = 0;
> +
> +    if (bcd_get_sgn(bcd) == 0) {
> +        return false;
> +    }
> +
> +    for (i = 1; i < 32; i++) {
> +        bcd_get_digit(bcd, i, &invalid);
> +        if (unlikely(invalid)) {
> +            return false;
> +        }
> +    }
> +    return true;
> +}
> +
>  static int bcd_cmp_zero(ppc_avr_t *bcd)
>  {
>      if (bcd->u64[HI_IDX] == 0 && (bcd->u64[LO_IDX] >> 4) == 0) {
> @@ -3013,18 +3031,13 @@ uint32_t helper_bcdcpsgn(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps)
>  
>  uint32_t helper_bcdsetsgn(ppc_avr_t *r, ppc_avr_t *b, uint32_t ps)
>  {
> -    int i;
> -    int invalid = 0;
>      int sgnb = bcd_get_sgn(b);
>  
>      *r = *b;
>      bcd_put_digit(r, bcd_preferred_sgn(sgnb, ps), 0);
>  
> -    for (i = 1; i < 32; i++) {
> -        bcd_get_digit(b, i, &invalid);
> -        if (unlikely(invalid)) {
> -            return CRF_SO;
> -        }
> +    if (bcd_is_valid(b) == false) {
> +        return CRF_SO;
>      }
>  
>      return bcd_cmp_zero(r);

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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