There are many difference between D and UD. It is ugly to handle them in one if
-----Original Message----- From: Yang, Rong R Sent: Tuesday, July 4, 2017 7:42 AM To: Wang, Rander <rander.w...@intel.com>; inte...@intelfx.name; beignet@lists.freedesktop.org Cc: Song, Ruiling <ruiling.s...@intel.com> Subject: RE: [Beignet] [PATCH V4] backend: add global immediate optimization GEN is support mixed type instructions, mixed UD and UW. For example, UD * UW. How about handle the U/UD in one if branch? > -----Original Message----- > From: Beignet [mailto:beignet-boun...@lists.freedesktop.org] On Behalf > Of Wang, Rander > Sent: Monday, July 3, 2017 9:33 > To: inte...@intelfx.name; beignet@lists.freedesktop.org > Cc: Song, Ruiling <ruiling.s...@intel.com> > Subject: Re: [Beignet] [PATCH V4] backend: add global immediate > optimization > > For D + UD, D is considered as UD by HW. > > -----Original Message----- > From: Ivan Shapovalov [mailto:inte...@intelfx.name] > Sent: Saturday, July 1, 2017 2:26 AM > To: Wang, Rander <rander.w...@intel.com>; > beignet@lists.freedesktop.org > Cc: Song, Ruiling <ruiling.s...@intel.com> > Subject: Re: [Beignet] [PATCH V4] backend: add global immediate > optimization > > On 2017-06-30 at 15:36 +0300, Ivan Shapovalov wrote: > > On 2017-06-30 at 01:46 +0000, Wang, Rander wrote: > > > Hi, > > > > > > The abs of UD has to be done if it is encoded in instruction no > > > matter it make sense or not. > > > And I have discussed with my collage and refine it. > > > First we inspect the HW behavior of ABS(UD), -(UD) and find > > > that > > > ABS(UD) = UD, > > > -(UD) = the result of -(UD) on CPU. > > > > > > So the abs calculation can be removed and this will make it > > > compiled pass. > > > > > > Rander > > > > Hi, > > > > OK, but what about reading from .value.ud if the corresponding .type > > is not GEN_TYPE_UD? Is this a concern? Which operand type > > combinations are possible? > > > > I mean, due to an || in the conditional it looks like it is possible > for either of the operands to not be a GEN_TYPE_D. Suppose the first > operand is a signed dword (GEN_TYPE_D) that holds a negative value and > has the ABS flag. In this case the new code will yield a significantly wrong > result. Is this possible? > > -- > Ivan Shapovalov / intelfx / > _______________________________________________ > Beignet mailing list > Beignet@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/beignet _______________________________________________ Beignet mailing list Beignet@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/beignet
