On Wed, Oct 26, 2016 at 11:18:58AM -0200, Jose Ricardo Ziviani wrote:
> bcdctz. converts from BCD to Zoned numeric format. Zoned format uses
> a byte to represent a digit where the most significant nibble is 0x3
> or 0xf, depending on the preferred signal.
>
> Signed-off-by: Jose Ricardo Ziviani <jos...@linux.vnet.ibm.com>
> ---
> target-ppc/helper.h | 1 +
> target-ppc/int_helper.c | 54
> +++++++++++++++++++++++++++++++++++++
> target-ppc/translate/vmx-impl.inc.c | 7 +++--
> 3 files changed, 60 insertions(+), 2 deletions(-)
>
> diff --git a/target-ppc/helper.h b/target-ppc/helper.h
> index f460635..3b928b8 100644
> --- a/target-ppc/helper.h
> +++ b/target-ppc/helper.h
> @@ -372,6 +372,7 @@ DEF_HELPER_4(bcdsub, i32, avr, avr, avr, i32)
> DEF_HELPER_3(bcdcfn, i32, avr, avr, i32)
> DEF_HELPER_2(bcdctn, i32, avr, avr)
> DEF_HELPER_3(bcdcfz, i32, avr, avr, i32)
> +DEF_HELPER_3(bcdctz, i32, avr, avr, i32)
>
> DEF_HELPER_2(xsadddp, void, env, i32)
> DEF_HELPER_2(xssubdp, void, env, i32)
> diff --git a/target-ppc/int_helper.c b/target-ppc/int_helper.c
> index 8cbbdfc..e0a84bb 100644
> --- a/target-ppc/int_helper.c
> +++ b/target-ppc/int_helper.c
> @@ -2768,6 +2768,60 @@ uint32_t helper_bcdcfz(ppc_avr_t *r, ppc_avr_t *b,
> uint32_t ps)
> *r = ret;
> return cr;
> }
> +
> +uint32_t helper_bcdctz(ppc_avr_t *r, ppc_avr_t *b, uint32_t ps)
> +{
> + int i;
> + int j;
> + int cr = 0;
> + int invalid = 0;
> + uint8_t digit = 0;
> + int sgnb = bcd_get_sgn(b);
> + int zone_lead = (ps) ? 0xF0 : 0x30;
> + ppc_avr_t ret = { .u64 = { 0, 0 } };
> +
> + int eq_flag = (b->u64[HI_IDX] == 0) && ((b->u64[LO_IDX] >> 4) == 0);
> + int ox_flag = (b->u64[HI_IDX] != 0);
This doesn't look right. The zoned format can accomodate 16 digits.
The low word of the packed format can accomodate 15 digits + sign. So
it should be possible to convert a packed for with a value in the low
nibble of the upper word.
> + for (i = 31, j = 16; i > 1; i -= 2, j--) {
Again not seeing any point for the reverse order.
> + digit = get_nibble(b, j);
> + ret.u8[BCD_DIG_BYTE(i)] = zone_lead + digit;
> +
> + if (unlikely(digit > 9)) {
> + invalid = 1;
> + }
> + }
> +
> + if (unlikely(!sgnb)) {
> + sgnb = (!get_nibble(b, 0)) ? 1 : -1;
> + }
Doesn't bcd_get_sgn() returning 0 indicate a badly encoded sign
point. In which case you should set invalid, rather than making up a
sign according to this apparently arbitrary scheme.
> +
> + if (ps) {
> + bcd_put_digit(&ret, (sgnb == 1) ? 0xC : 0xD, 1);
> + } else {
> + bcd_put_digit(&ret, (sgnb == 1) ? 0x3 : 0x7, 1);
> + }
> + bcd_put_digit(&ret, get_nibble(b, 1), 0);
> +
> + if (!eq_flag) {
> + cr = (sgnb == 1) ? 1 << CRF_GT : 1 << CRF_LT;
> + } else {
> + cr = 1 << CRF_EQ;
> + }
> +
> + if (ox_flag) {
> + cr |= 1 << CRF_SO;
> + }
> +
> + if (unlikely(invalid)) {
> + cr = 1 << CRF_SO;
> + }
> +
> + *r = ret;
> +
> + return cr;
> +}
> +
> void helper_vsbox(ppc_avr_t *r, ppc_avr_t *a)
> {
> int i;
> diff --git a/target-ppc/translate/vmx-impl.inc.c
> b/target-ppc/translate/vmx-impl.inc.c
> index 9192f8f..62c44f0 100644
> --- a/target-ppc/translate/vmx-impl.inc.c
> +++ b/target-ppc/translate/vmx-impl.inc.c
> @@ -918,6 +918,7 @@ GEN_BCD(bcdsub)
> GEN_BCD2(bcdcfn)
> GEN_BCD3(bcdctn)
> GEN_BCD2(bcdcfz)
> +GEN_BCD2(bcdctz)
>
> static void gen_xpnd04_1(DisasContext *ctx)
> {
> @@ -927,7 +928,8 @@ static void gen_xpnd04_1(DisasContext *ctx)
> case 2:
> break; /* bcdcfsq. */
> case 4:
> - break; /* bcdctz. */
> + gen_bcdctz(ctx);
> + break;
> case 5:
> gen_bcdctn(ctx);
> break;
> @@ -952,7 +954,8 @@ static void gen_xpnd04_2(DisasContext *ctx)
> case 2:
> break; /* bcdcfsq. */
> case 4:
> - break; /* bcdctz. */
> + gen_bcdctz(ctx);
> + break;
> case 6:
> gen_bcdcfz(ctx);
> break;
--
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
signature.asc
Description: PGP signature
