<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Nov 28, 2016, at 1:31 PM, Gurunath Kadam via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" class="">llvm-dev@lists.llvm.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><p style="margin:0px 0px 1em;padding:0px;border:0px;font-size:15px;clear:both;color:rgb(36,39,41);font-family:arial,"helvetica neue",helvetica,sans-serif" class="">I have following LLVM IR instruction:</p><p style="margin:0px 0px 1em;padding:0px;border:0px;font-size:15px;clear:both;color:rgb(36,39,41);font-family:arial,"helvetica neue",helvetica,sans-serif" class=""><code style="margin:0px;padding:1px 5px;border:0px;font-size:13px;font-family:consolas,menlo,monaco,"lucida console","liberation mono","dejavu sans mono","bitstream vera sans mono","courier new",monospace,sans-serif;background-color:rgb(239,240,241);white-space:pre-wrap" class="">%ptrA = getelementptr float, float addrspace(1)* %A, i32 %id</code></p><p style="margin:0px 0px 1em;padding:0px;border:0px;font-size:15px;clear:both;color:rgb(36,39,41);font-family:arial,"helvetica neue",helvetica,sans-serif" class="">To get the <code style="margin:0px;padding:1px 5px;border:0px;font-size:13px;font-family:consolas,menlo,monaco,"lucida console","liberation mono","dejavu sans mono","bitstream vera sans mono","courier new",monospace,sans-serif;background-color:rgb(239,240,241);white-space:pre-wrap" class="">addrspace</code> value, do I use function call <code style="margin:0px;padding:1px 5px;border:0px;font-size:13px;font-family:consolas,menlo,monaco,"lucida console","liberation mono","dejavu sans mono","bitstream vera sans mono","courier new",monospace,sans-serif;background-color:rgb(239,240,241);white-space:pre-wrap" class="">getAddressSpace()</code> or <code style="margin:0px;padding:1px 5px;border:0px;font-size:13px;font-family:consolas,menlo,monaco,"lucida console","liberation mono","dejavu sans mono","bitstream vera sans mono","courier new",monospace,sans-serif;background-color:rgb(239,240,241);white-space:pre-wrap" class="">getPointerAddressSpace()</code> ?</p><p style="margin:0px 0px 1em;padding:0px;border:0px;font-size:15px;clear:both;color:rgb(36,39,41);font-family:arial,"helvetica neue",helvetica,sans-serif" class="">Using <span style="background-color:rgb(239,240,241);font-family:consolas,menlo,monaco,"lucida console","liberation mono","dejavu sans mono","bitstream vera sans mono","courier new",monospace,sans-serif;font-size:13px;white-space:pre-wrap" class="">getAddressSpace()</span> results in following error:</p><p style="margin:0px 0px 1em;padding:0px;border:0px;font-size:15px;clear:both;color:rgb(36,39,41);font-family:arial,"helvetica neue",helvetica,sans-serif" class=""><span style="font-family:consolas,menlo,monaco,"lucida console","liberation mono","dejavu sans mono","bitstream vera sans mono","courier new",monospace,sans-serif;font-size:13px;background-color:rgb(239,240,241)" class="">'class llvm::Instruction' has no member named 'getAddressSpace'</span><br class=""></p><p style="margin:0px 0px 1em;padding:0px;border:0px;font-size:15px;clear:both;color:rgb(36,39,41);font-family:arial,"helvetica neue",helvetica,sans-serif" class="">But I see these methods in Instruction.h implemented for getelementptr inst class.</p><div class=""><br class=""></div></div></div></blockquote><div><br class=""></div><div>You need to cast the instruction to the right subclass before being able to call the method that are implemented for the particular subclass.</div><div><br class=""></div><div>If you have an “Instruction *” you can only call on it methods that defined in the class Instruction. (Note that this is not LLVM specific, this is generic C++).</div><div><br class=""></div><div>LLVM has its own RTTI implementation, when you have an instruction and you don’t know if it is a particular subclass, you can “try” to cast it to the type you want:</div><div><br class=""></div><div>if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(I)) {</div><div> … // use GEP</div><div>}</div><div><br class=""></div><div><br class=""></div><div>— </div><div>Mehdi</div><div><br class=""></div></div></body></html>