Speed up addRegisterDead by adding more fast checks before performing the expensive

subregister query, and by increasing the size of the subregister hashtable so
that there are fewer collisions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54781 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index c952293976..d602e2442f 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -834,7 +834,9 @@ bool MachineInstr::addRegisterDead(unsigned IncomingReg,
       // There exists a super-register that's marked dead.
       if (RegInfo->isSuperRegister(IncomingReg, Reg))
         return true;
-      if (RegInfo->isSubRegister(IncomingReg, Reg))
+      if (RegInfo->getSubRegisters(IncomingReg) &&
+          RegInfo->getSuperRegisters(Reg) &&
+          RegInfo->isSubRegister(IncomingReg, Reg))
         DeadOps.push_back(i);
     }
   }