diff options
Diffstat (limited to 'llvm/lib/Target/Hexagon/HexagonRDFOpt.cpp')
| -rw-r--r-- | llvm/lib/Target/Hexagon/HexagonRDFOpt.cpp | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/llvm/lib/Target/Hexagon/HexagonRDFOpt.cpp b/llvm/lib/Target/Hexagon/HexagonRDFOpt.cpp index d735acf457b..642a8785def 100644 --- a/llvm/lib/Target/Hexagon/HexagonRDFOpt.cpp +++ b/llvm/lib/Target/Hexagon/HexagonRDFOpt.cpp @@ -289,7 +289,10 @@ bool HexagonRDFOpt::runOnMachineFunction(MachineFunction &MF) { HexagonRegisterAliasInfo HAI(HRI); TargetOperandInfo TOI(HII); DataFlowGraph G(MF, HII, HRI, *MDT, MDF, HAI, TOI); - G.build(); + // Dead phi nodes are necessary for copy propagation: we can add a use + // of a register in a block where it would need a phi node, but which + // was dead (and removed) during the graph build time. + G.build(BuildOptions::KeepDeadPhis); if (RDFDump) dbgs() << "Starting copy propagation on: " << MF.getName() << '\n' |
