Ignore non-allocatable physical registers in live interval analysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10449 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 8 insertions, 0 deletions

diff --git a/include/llvm/CodeGen/LiveVariables.h b/include/llvm/CodeGen/LiveVariables.h
index 3a0d044c59..737dabc1ae 100644
--- a/include/llvm/CodeGen/LiveVariables.h
+++ b/include/llvm/CodeGen/LiveVariables.h
@@ -202,6 +202,10 @@ public:
   /// register.
   VarInfo &getVarInfo(unsigned RegIdx);
 
+  const std::vector<bool>& getAllocatablePhysicalRegisters() const {
+    return AllocatablePhysicalRegisters;
+  }
+
   void MarkVirtRegAliveInBlock(VarInfo &VRInfo, const BasicBlock *BB);
   void HandleVirtRegUse(VarInfo &VRInfo, MachineBasicBlock *MBB,
                        	MachineInstr *MI);
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 2a31e66851..52cf73be8b 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -183,6 +183,10 @@ void LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock* mbb,
                                               unsigned reg)
 {
     DEBUG(std::cerr << "\t\t\tregister: ";printRegName(reg); std::cerr << '\n');
+    if (!lv_->getAllocatablePhysicalRegisters()[reg]) {
+        DEBUG(std::cerr << "\t\t\t\tnon allocatable register: ignoring\n");
+        return;
+    }
 
     unsigned start = getInstructionIndex(*mi);
     unsigned end = start;