diff options
| -rw-r--r-- | lib/CodeGen/AggressiveAntiDepBreaker.cpp | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/lib/CodeGen/AggressiveAntiDepBreaker.cpp index 2ee7767115..25c438c961 100644 --- a/lib/CodeGen/AggressiveAntiDepBreaker.cpp +++ b/lib/CodeGen/AggressiveAntiDepBreaker.cpp @@ -403,8 +403,18 @@ void AggressiveAntiDepBreaker::PrescanInstruction(MachineInstr *MI, continue; // Update def for Reg and aliases. - for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) + for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) { + // We need to be careful here not to define already-live super registers. + // If the super register is already live, then this definition is not + // a definition of the whole super register (just a partial insertion + // into it). Earlier subregister definitions (which we've not yet visited + // because we're iterating bottom-up) need to be linked to the same group + // as this definition. + if (TRI->isSuperRegister(Reg, *AI) && State->IsLive(*AI)) + continue; + DefIndices[*AI] = Count; + } } } |