diff options
| -rw-r--r-- | llvm/include/llvm/Analysis/CFGPrinter.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/llvm/include/llvm/Analysis/CFGPrinter.h b/llvm/include/llvm/Analysis/CFGPrinter.h index 035764837e6..f73a13f533c 100644 --- a/llvm/include/llvm/Analysis/CFGPrinter.h +++ b/llvm/include/llvm/Analysis/CFGPrinter.h @@ -118,6 +118,36 @@ struct DOTGraphTraits<const Function*> : public DefaultDOTGraphTraits { } return ""; } + + /// Display the raw branch weights from PGO. + std::string getEdgeAttributes(const BasicBlock *Node, succ_const_iterator I, + const Function *F) { + const TerminatorInst *TI = Node->getTerminator(); + if (TI->getNumSuccessors() == 1) + return ""; + + MDNode *WeightsNode = TI->getMetadata(LLVMContext::MD_prof); + if (!WeightsNode) + return ""; + + MDString *MDName = cast<MDString>(WeightsNode->getOperand(0)); + if (MDName->getString() != "branch_weights") + return ""; + + unsigned OpNo = I.getSuccessorIndex() + 1; + if (OpNo >= WeightsNode->getNumOperands()) + return ""; + ConstantInt *Weight = + mdconst::dyn_extract<ConstantInt>(WeightsNode->getOperand(OpNo)); + if (!Weight) + return ""; + + // Append a 'W' to indicate that these are weights rather than actual + // profile + // count (due to scaling). + Twine Attrs = "label=\"W:" + Twine(Weight->getZExtValue()) + "\""; + return Attrs.str(); + } }; } // End llvm namespace |
