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copied!<p>No, there is no way to use the comments' contents this way, not without significantly changing the IR parser. However, there's no need to re-invent the wheel; there's a mechanism in LLVM which is intended <strong>precisely</strong> for these sorts of things - transferring information from the front-end into an LLVM pass - and that is <a href="http://blog.llvm.org/2010/04/extensible-metadata-in-llvm-ir.html" rel="nofollow noreferrer">metadata</a>.</p> <p>So whatever or whoever is adding this information to the IR should add it with metadata instead - see these sources for more information on how to do that:</p> <ul> <li><a href="http://llvm.org/docs/LangRef.html#metadata" rel="nofollow noreferrer">http://llvm.org/docs/LangRef.html#metadata</a></li> <li><a href="http://llvm.org/docs/LangRef.html#named-metadata" rel="nofollow noreferrer">http://llvm.org/docs/LangRef.html#named-metadata</a></li> <li><a href="https://stackoverflow.com/questions/13425794/adding-metadata-to-instructions-in-llvm-ir">Adding Metadata to Instructions in LLVM IR</a></li> <li><a href="https://stackoverflow.com/questions/9525947/attaching-metadata">How to attach metadata to LLVM IR using the C++ API?</a></li> <li><a href="https://stackoverflow.com/questions/6973570/how-to-add-a-metadata-string-to-an-llvm-module-with-the-c-api">How to add a Metadata String to an LLVM module with the C++ API?</a></li> </ul> <p>If you have no control over the generation of data, then you should add some pre-processing step in which you convert the comments to metadata.</p> <p>In the end the IR should look something like:</p> <pre> define internal void @MDFilter() #0 { entry: %mdContext = alloca %struct.MD5_CTX, align 8<b>, !freq !1</b> %bytes = alloca i32, align 4 %data = alloca [16 x i8], align 16 call void @MD5Init(%struct.MD5_CTX* %mdContext) br label %while.cond<b>, !outedge !2</b> ... <b>!1 = metadata !{i32 2} !2 = metadata !{float 2.0}</b> </pre> <p>And your pass needs to look for these <code>!freq</code> and <code>!outedge</code> nodes.</p>

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