Stub out a new LiveDebugVariables pass.

This analysis is going to run immediately after LiveIntervals. It will stay
alive during register allocation and keep track of user variables mentioned in
DBG_VALUE instructions.

When the register allocator is moving values between registers and the stack, it
is very hard to keep track of DBG_VALUE instructions. We usually get it wrong.
This analysis maintains a data structure that makes it easy to update DBG_VALUE
instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120385 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/CodeGen/CodeGen.cpp b/lib/CodeGen/CodeGen.cpp
index fec98d26a1..515e6f9fde 100644
--- a/lib/CodeGen/CodeGen.cpp
+++ b/lib/CodeGen/CodeGen.cpp
@@ -23,6 +23,7 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeDeadMachineInstructionElimPass(Registry);
   initializeGCModuleInfoPass(Registry);
   initializeIfConverterPass(Registry);
+  initializeLiveDebugVariablesPass(Registry);
   initializeLiveIntervalsPass(Registry);
   initializeLiveStacksPass(Registry);
   initializeLiveVariablesPass(Registry);