Preserve the register coallescer, and update live intervals more correctly by triggering a renumbering after phi elimination.

llvm-svn: 51780

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/StrongPHIElimination.cpp b/llvm/lib/CodeGen/StrongPHIElimination.cpp
index 97e4fb9b6e7..449ef38a3a1 100644
--- a/llvm/lib/CodeGen/StrongPHIElimination.cpp
+++ b/llvm/lib/CodeGen/StrongPHIElimination.cpp
@@ -27,6 +27,7 @@
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterCoalescer.h"
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/ADT/DepthFirstIterator.h"
@@ -34,7 +35,6 @@
 #include "llvm/Support/Compiler.h"
 using namespace llvm;
 
-
 namespace {
   struct VISIBILITY_HIDDEN StrongPHIElimination : public MachineFunctionPass {
     static char ID; // Pass identification, replacement for typeid
@@ -74,6 +74,7 @@ namespace {
       
       // TODO: Actually make this true.
       AU.addPreserved<LiveIntervals>();
+      AU.addPreserved<RegisterCoalescer>();
       MachineFunctionPass::getAnalysisUsage(AU);
     }
     
@@ -921,5 +922,7 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
     PInstr->eraseFromParent();
   }
   
+  LI.computeNumbering();
+  
   return true;
 }