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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Anton Lokhmotov wrote:<o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>> Given that at least two companies have found metadata useful for<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>> representing OpenCL C features in LLVM-IR, I think the community needs to<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>> reconsider the use of metadata, perhaps introducing a 'sticky' variant of<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>> it? <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>We at Intel are also using metadata for our implementation. This approach is very useful for a few reasons:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>First, when compiling OpenCL C code to llvm, some important information about the kernel arguments is lost. i.e. typedefs are lost, structures are sometimes disassembled. We’re adding a string containing the interesting part original function signature. This can also be used for providing data about the kernel arguments, validating the arguments set by the user, etc…<span style='color:#1F497D'><o:p></o:p></span></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Second, we use a global metadata node, which enumerates all the kernel functions. This can be used to quickly enumerate the kernels in a program, instead of passing the whole module.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Third, for each kernel we hold the kernel attributes in the same metadata: vector type hint, required workgroup size and workgroup size hint.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Last, we also hold in the metadata a list of the local variables defined in that kernel. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Thanks<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> Guy<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><img width=490 height=135 id="Picture_x0020_1" src="cid:image001.png@01CBB10A.48487AD0" alt="new_email_signature_guy2"><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div><font face="monospace">---------------------------------------------------------------------<br>
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