<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Sep 8, 2009, at 2:46 PM, Susan Horwitz wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>I am trying to implement node splitting to transform irreducible CFGS to <br>reducible ones. This means making copies of some basic blocks, which in <br>turn means making copies of individual instructions. I can use the <br>"clone" function to make an exact copy, but then I need to change some <br>operands. For example, when I copy<br> <span class="Apple-tab-span" style="white-space:pre"> </span>%1 = ...<br> <span class="Apple-tab-span" style="white-space:pre"> </span>%2 = add %1, 5<br><br>I get<br> <span class="Apple-tab-span" style="white-space:pre"> </span>%3 = ...<br> <span class="Apple-tab-span" style="white-space:pre"> </span>%4 = add %1, 5<br><br>and I need to change the %1 operand in the copy to be %3.<br><br>The only way I see to do this is to create a new instruction instead of a <br>clone, using a big switch on the opcode (since different instructions' <br>constructors have different parameters).<br><br>Anyone know of an easier way to do this?<br><br></div></blockquote><div><br></div><div>Are you using CloneBasicBlock? If so, you should pass it a ValueMap. You can then iterate over the instructions in the new basicblock and update the instruction operand references.</div><div><br></div><div>Check out CloneFunction.cpp for some examples.</div><div><br></div><div>-Tanya</div><div><br></div><div><br></div><div><br></div><div><br></div><br><blockquote type="cite"><div>_______________________________________________<br>LLVM Developers mailing list<br><a href="mailto:LLVMdev@cs.uiuc.edu">LLVMdev@cs.uiuc.edu</a> <a href="http://llvm.cs.uiuc.edu">http://llvm.cs.uiuc.edu</a><br><a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev</a><br></div></blockquote></div><br></body></html>