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<p class="MsoNormal"><span style="color:#1F497D">Sam,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I guess metadata attached right to the function should work as well. Nothing would hold us from forming the same list of strings in a single metadata entry. The only problem I see here if someone else would want
to use function metadata attachment for some other reason, so we will need to search and/or merge it.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Given that consideration attributes looks better to me, they are already a top-level list.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="color:#1F497D">Stas<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b>From:</b> Liu, Yaxun (Sam) <br>
<b>Sent:</b> 11 ΝΑΡ 2016 Η. 10:18<br>
<b>To:</b> Anastasia Stulova <Anastasia.Stulova@arm.com>; Mekhanoshin, Stanislav <Stanislav.Mekhanoshin@amd.com>; cfe-dev (cfe-dev@lists.llvm.org) <cfe-dev@lists.llvm.org>; Pan, Xiuli <xiuli.pan@intel.com>; Bader, Alexey (alexey.bader@intel.com) <alexey.bader@intel.com><br>
<b>Cc:</b> Stellard, Thomas <Tom.Stellard@amd.com>; Sumner, Brian <Brian.Sumner@amd.com>; nd <nd@arm.com><br>
<b>Subject:</b> RE: [OpenCL] Representing kernel attributes by LLVM target-dependent attribute-value pairs instead of metadata<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">Hi Anastasia,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Target-dependent attribute-value pair is not limited to one target. It is just a pair of strings attached to a function. It can be used by different targets as far as they accept a commonly agreed attribute name.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">The function metadata also requires a commonly agreed attribute name. In this aspect it is similar to target-dependent attribute-value pair. However it may be more difficult to manipulate.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Stas, any comments on this?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Thanks.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Sam<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b>From:</b> Anastasia Stulova [<a href="mailto:Anastasia.Stulova@arm.com">mailto:Anastasia.Stulova@arm.com</a>]
<br>
<b>Sent:</b> Wednesday, May 11, 2016 12:32 PM<br>
<b>To:</b> Mekhanoshin, Stanislav <<a href="mailto:Stanislav.Mekhanoshin@amd.com">Stanislav.Mekhanoshin@amd.com</a>>; Liu, Yaxun (Sam) <<a href="mailto:Yaxun.Liu@amd.com">Yaxun.Liu@amd.com</a>>; cfe-dev (<a href="mailto:cfe-dev@lists.llvm.org">cfe-dev@lists.llvm.org</a>)
<<a href="mailto:cfe-dev@lists.llvm.org">cfe-dev@lists.llvm.org</a>>; Pan, Xiuli <<a href="mailto:xiuli.pan@intel.com">xiuli.pan@intel.com</a>>; Bader, Alexey (<a href="mailto:alexey.bader@intel.com">alexey.bader@intel.com</a>) <<a href="mailto:alexey.bader@intel.com">alexey.bader@intel.com</a>><br>
<b>Cc:</b> Stellard, Thomas <<a href="mailto:Tom.Stellard@amd.com">Tom.Stellard@amd.com</a>>; Sumner, Brian <<a href="mailto:Brian.Sumner@amd.com">Brian.Sumner@amd.com</a>>; nd <<a href="mailto:nd@arm.com">nd@arm.com</a>><br>
<b>Subject:</b> RE: [OpenCL] Representing kernel attributes by LLVM target-dependent attribute-value pairs instead of metadata<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-GB" style="color:#1F497D">Hi Sam,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="color:#1F497D">Interesting idea, I am just concerned whether target-dependent attribute-value pairs are really correct for this use case. Because kernel attributes aren’t really target dependent.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="color:#1F497D">However, I agree that current approach is painful enough. Do you think switching to function metadata (see llvm@r235783) would help instead? This way we will also have the kernel attributes directly
accessible from the function, simplifying querying them (as compared to what we have at the moment).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="color:#1F497D">Thanks,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="color:#1F497D">Anastasia<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma",sans-serif">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma",sans-serif"> Mekhanoshin, Stanislav [<a href="mailto:Stanislav.Mekhanoshin@amd.com">mailto:Stanislav.Mekhanoshin@amd.com</a>]
<br>
<b>Sent:</b> 09 May 2016 21:14<br>
<b>To:</b> Liu, Yaxun (Sam); cfe-dev (<a href="mailto:cfe-dev@lists.llvm.org">cfe-dev@lists.llvm.org</a>); Anastasia Stulova; Pan, Xiuli; Bader, Alexey (<a href="mailto:alexey.bader@intel.com">alexey.bader@intel.com</a>)<br>
<b>Cc:</b> Stellard, Thomas; Sumner, Brian<br>
<b>Subject:</b> RE: [OpenCL] Representing kernel attributes by LLVM target-dependent attribute-value pairs instead of metadata<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">It will make our life much easier I would say.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="color:#1F497D">Stas<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="RU" style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b>From:</b> Liu, Yaxun (Sam) <br>
<b>Sent:</b> Monday, May 09, 2016 1:05 PM<br>
<b>To:</b> cfe-dev (<a href="mailto:cfe-dev@lists.llvm.org">cfe-dev@lists.llvm.org</a>) <<a href="mailto:cfe-dev@lists.llvm.org">cfe-dev@lists.llvm.org</a>>; 'anastasia.stulova@arm.com' <<a href="mailto:anastasia.stulova@arm.com">anastasia.stulova@arm.com</a>>;
Pan, Xiuli <<a href="mailto:xiuli.pan@intel.com">xiuli.pan@intel.com</a>>; Bader, Alexey (<a href="mailto:alexey.bader@intel.com">alexey.bader@intel.com</a>) <<a href="mailto:alexey.bader@intel.com">alexey.bader@intel.com</a>><br>
<b>Cc:</b> Stellard, Thomas <<a href="mailto:Tom.Stellard@amd.com">Tom.Stellard@amd.com</a>>; Sumner, Brian <<a href="mailto:Brian.Sumner@amd.com">Brian.Sumner@amd.com</a>>; Mekhanoshin, Stanislav <<a href="mailto:Stanislav.Mekhanoshin@amd.com">Stanislav.Mekhanoshin@amd.com</a>><br>
<b>Subject:</b> [OpenCL] Representing kernel attributes by LLVM target-dependent attribute-value pairs instead of metadata<o:p></o:p></p>
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<p class="MsoNormal"><span lang="RU"><o:p> </o:p></span></p>
<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">When SPIR 1.2/2.0 spec was developed, there was no target-dependent attribute-value pair in LLVM. As such, kernel attributes were represented as metadata.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This caused lots of inconvenience since these metadata are difficult to manipulate/change when kernel functions went through transformations in backends.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Now LLVM supports target-dependent attribute-value pair, I am wondering whether it is time to use that to represent kernel attributes.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">e.g. something like (just to give an idea, not exact llvm IR)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">kernel void foo(global int*a, sampler_t s); #1<o:p></o:p></p>
<p class="MsoNormal">#1 = {<o:p></o:p></p>
<p class="MsoNormal">reqd_work_group_size=”1 1 1”,<o:p></o:p></p>
<p class="MsoNormal">kernel_arg_type=”int *, sampler_t”,<o:p></o:p></p>
<p class="MsoNormal">…<o:p></o:p></p>
<p class="MsoNormal">}<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">basically we keep the info conveyed by the original metadata but attach them to the kernel function as attribute/value pair. This will make these attributes much easier to manipulate/change.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any feedbacks? Thanks.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Sam<o:p></o:p></p>
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