From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35377) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bzcFG-0008Hh-4y for qemu-devel@nongnu.org; Thu, 27 Oct 2016 00:24:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bzcFB-0007Av-U1 for qemu-devel@nongnu.org; Thu, 27 Oct 2016 00:24:50 -0400 Date: Thu, 27 Oct 2016 12:35:19 +1100 From: David Gibson Message-ID: <20161027013519.GC19918@umbus.fritz.box> References: <1477487938-23921-1-git-send-email-joserz@linux.vnet.ibm.com> <1477487938-23921-4-git-send-email-joserz@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="m51xatjYGsM+13rf" Content-Disposition: inline In-Reply-To: <1477487938-23921-4-git-send-email-joserz@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH] 3/4] target-ppc: Implement bcdcfz. instruction List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jose Ricardo Ziviani Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, nikunj@linux.vnet.ibm.com, bharata@linux.vnet.ibm.com --m51xatjYGsM+13rf Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Oct 26, 2016 at 11:18:57AM -0200, Jose Ricardo Ziviani wrote: > bcdcfz. converts from Zoned numeric format to BCD. Zoned format uses > a byte to represent a digit where the most significant nibble is 0x3 > or 0xf, depending on the preferred signal. >=20 > Signed-off-by: Jose Ricardo Ziviani > --- > target-ppc/helper.h | 1 + > target-ppc/int_helper.c | 55 +++++++++++++++++++++++++++++++= ++++++ > target-ppc/translate/vmx-impl.inc.c | 7 +++-- > 3 files changed, 61 insertions(+), 2 deletions(-) >=20 > diff --git a/target-ppc/helper.h b/target-ppc/helper.h > index 92eaaf0..f460635 100644 > --- a/target-ppc/helper.h > +++ b/target-ppc/helper.h > @@ -371,6 +371,7 @@ DEF_HELPER_4(bcdadd, i32, avr, avr, avr, i32) > 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) > =20 > 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 cffe82c..8cbbdfc 100644 > --- a/target-ppc/int_helper.c > +++ b/target-ppc/int_helper.c > @@ -2459,6 +2459,17 @@ static int bcd_preferred_sgn(int sgn, int ps) > } > } > =20 > +static uint8_t get_nibble(ppc_avr_t *bcd, int n) > +{ > + uint8_t result; > + if (!(n & 1)) { > + result =3D bcd->u8[BCD_DIG_BYTE(n)] & 0xF; > + } else { > + result =3D bcd->u8[BCD_DIG_BYTE(n)] >> 4; > + } > + return result; > +} This can be merged with bcd_get_digit() without too much effort. > static uint8_t bcd_get_digit(ppc_avr_t *bcd, int n, int *invalid) > { > uint8_t result; > @@ -2713,6 +2724,50 @@ uint32_t helper_bcdctn(ppc_avr_t *r, ppc_avr_t *b) > return cr; > } > =20 > +uint32_t helper_bcdcfz(ppc_avr_t *r, ppc_avr_t *b, uint32_t ps) > +{ > + int i; > + int j =3D 0; > + int cr =3D 0; > + int invalid =3D 0; > + int eq_flag =3D 0; > + int zone_digit =3D 0; > + ppc_avr_t ret =3D { .u64 =3D { 0, 0 } }; > + int sgnb =3D get_nibble(b, 1); > + > + if (unlikely(((sgnb < 0xA) && ps) || > + ((get_nibble(b, 0) > 0x9) && !ps))) { The second half of this condition doesn't belong here. It's a requirement for both ps values, and would make more sense applied along with the same test on the other digits. > + invalid =3D 1; > + } > + > + for (i =3D 31, j =3D 16; i > 1; i -=3D 2, j--) { I don't see why you're doing this in reverse order. > + zone_digit =3D get_nibble(b, i); > + if (unlikely((ps && zone_digit !=3D 0xF) || > + (!ps && zone_digit !=3D 0x3))) { > + invalid =3D 1; In this and the other instructions it would make sense to break out of the function as soon as you detect an invalid encoding. > + } You never check for invalid encoding in the low input nibble (i.e. value > 0x9). > + eq_flag +=3D zone_digit; What?? How on earth does adding up the zone digits help you. For a valid encoding the answer should always be either 0x2d (PS=3D0) or 0xe1 (PS=3D1). > + bcd_put_digit(&ret, get_nibble(b, i - 1), j); > + } > + bcd_put_digit(&ret, get_nibble(b, 0), 1); > + > + if ((ps && (sgnb =3D=3D 0xB || sgnb =3D=3D 0xD)) || > + (!ps && (sgnb & 0x4))) { > + bcd_put_digit(&ret, BCD_NEG_PREF, 0); > + cr =3D (!eq_flag) ? 1 << CRF_LT : 1 << CRF_EQ; > + } else { > + bcd_put_digit(&ret, BCD_PLUS_PREF_1, 0); > + cr =3D (!eq_flag) ? 1 << CRF_GT : 1 << CRF_EQ; > + } > + > + if (unlikely(invalid)) { > + cr =3D 1 << CRF_SO; > + } > + > + *r =3D 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/v= mx-impl.inc.c > index 4364881..9192f8f 100644 > --- a/target-ppc/translate/vmx-impl.inc.c > +++ b/target-ppc/translate/vmx-impl.inc.c > @@ -917,6 +917,7 @@ GEN_BCD(bcdadd) > GEN_BCD(bcdsub) > GEN_BCD2(bcdcfn) > GEN_BCD3(bcdctn) > +GEN_BCD2(bcdcfz) > =20 > static void gen_xpnd04_1(DisasContext *ctx) > { > @@ -931,7 +932,8 @@ static void gen_xpnd04_1(DisasContext *ctx) > gen_bcdctn(ctx); > break; > case 6: > - break; /* bcdcfz. */ > + gen_bcdcfz(ctx); > + break; > case 7: > gen_bcdcfn(ctx); > break; > @@ -952,7 +954,8 @@ static void gen_xpnd04_2(DisasContext *ctx) > case 4: > break; /* bcdctz. */ > case 6: > - break; /* bcdcfz. */ > + gen_bcdcfz(ctx); > + break; > case 7: > gen_bcdcfn(ctx); > break; --=20 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 --m51xatjYGsM+13rf Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJYEVnUAAoJEGw4ysog2bOSJIUQAMOe8x+PpmBSIYeQOkiEJJuv COAOcARgEeVxfhv8p88tdGhXUtaZa2wZMKEgcyk7dapOC/LsvvWLHGUhY4czR+X3 kqzENtyc8q/nAv1uuB7TWj4eeIvtrQWYEZqClJZXzXPfi6kQwtvXya/FYQQVdX9y jL+Gv7BvUiZDk4KVbw3GAe508h8UBvtbRl74CYZC9ljK4nKCZCN3E0ZJUP/LjCNl UDt8iUwEB847NFu3P4z1v02KjGgT84argjGJHDkHdac4eCqC/1nsNK4XKnCLmaEJ n+T4gsP4QMNGsY2nwuS+GnVVXpWA+yhau5XdztGDLe1rN/o9+8bzihAQ3txkIW0b WmzkirYPvsh4VQAfqKDg9v3GMQ3cyH2YxUmxAPbBaEvpV8AaJg1gycrwE9hJ4kaT UU9hEtzr84k06BvISHRXs2QjgXmMsrbXn4RG0+2Hnf3Bid4/W3pkXKT+rPb6fns9 G3Ki2TLkyUKC1IW24B4i2CWLyg3xwd9/750puIvNz5cV2/Ba2dwnkmCSwh4lQbxy h9A3Hp8yWSrXm9r8izy1JxxbgPwvgijDwYy01bVCRt84LjPXAUHik9RuKL23TCqM S5j+IiRt5RQWvbSxON86hIyEWCstjz3MeTLLAxDGwjlDuFEUB+4E1BijxAbo/b8I SwPdUcZnV8z0vm6p/d3x =JPi6 -----END PGP SIGNATURE----- --m51xatjYGsM+13rf--