From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38717) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1faZs6-00011D-SR for qemu-devel@nongnu.org; Wed, 04 Jul 2018 00:58:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1faZs6-00019a-3E for qemu-devel@nongnu.org; Wed, 04 Jul 2018 00:58:30 -0400 Date: Wed, 4 Jul 2018 13:31:34 +1000 From: David Gibson Message-ID: <20180704033134.GE14043@umbus.fritz.box> References: <20180703151732.29843-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="7LkOrbQMr4cezO2T" Content-Disposition: inline In-Reply-To: <20180703151732.29843-1-richard.henderson@linaro.org> Subject: Re: [Qemu-devel] [PATCH for-3.1 0/7] target/ppc fp cleanups List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson Cc: qemu-devel@nongnu.org, programmingkidx@gmail.com, qemu-ppc@nongnu.org --7LkOrbQMr4cezO2T Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jul 03, 2018 at 08:17:25AM -0700, Richard Henderson wrote: > Beginning with John Arbuckle's fdiv test case, clean up some > of the fp helpers. As with fdiv, fre and fresqrt are missing > divide-by-zero exceptions. >=20 > I've also noticed that load/store were using arithmetic conversions > to/from float32. These should be using the non-arithmetic algorithms > listed in the manual. >=20 > Aside from cleaning up all of the rest of the helpers, I believe that > the implementation of the single-precision operations are incorrect. > They are currently implemented with the double-precision operation > followed by a round-to-single. This causes incorrect results via > double rounding. I believe better results could be had by using > these non-arithmetic converters to produce float32 operands, use the > proper float32 softfloat operations, and then convert back. >=20 > Anyway, all of this has been broken long enough that it'll need to > wait til next devel cycle before anything further gets done. Applied to ppc-for-3.1 (newly created). --=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 --7LkOrbQMr4cezO2T Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAls8P5QACgkQbDjKyiDZ s5LiQQ/9HV4VjL6bNDJ5ihhZkFTQ84/pBbt8LYVS/ibuUtMF0CKT5rbtHcLNbk6q hGfaMNGmsd++8mT6cmzSWXVQAllB7f4W+jYn8gseTkCP/h5w7ZyKf8kNb8JscP4n oSiH1QysV6BvGGWM2JridaEJVKxBq+KHJVsnOs8A6y+amdcWjDysgn+OS4fo7Im2 a0JOvQTjirPUDUMAI8m9gXcadu3H5cXxpUIUtq9/EsRwMDiIVOQIAZy+CYPBF4/R RKjiOF/CKHhktWpEa8atjZB/F+glc7Q+z1bM2/4Oz4RbgfOCH9/cf03HSti1H1I2 qiM8wD5a6SXtNBevyXNQD9RwWeGmBuvye54KTCmUVqVK6KRQn/l1p4PSyzOjBuJS yjnuPvh7m+cJrHuHR+oBrJUjKNvtiLc6zjWOk2U7brh7us2cTcWBWl7AT1uAHCu/ yKmu44SozxKHX7ceQV40nvcqT7EKJwOsG5Hgilbow2WxYDdpOFGuRGQj+KiDyWup Xfo71+TdQwp1ePxNAF0sg/2PWhi0ERTiOge7Su+cbvbylbVulOWh/14gtPcMWuHs 0ueEqWys04UXUjn/ZPi0ytUzmIP6ZU8+H4a7JG9IoIAYA+tymBIRNkyde87PI57u EBdbsCIFDh5Y98Z9RpPRdN8Tseenh/pKEdFzfsyPmQxyEINGrks= =ATvr -----END PGP SIGNATURE----- --7LkOrbQMr4cezO2T--