From c1f53c742620dd4f2460685477303002bba8a8d8 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Tue, 11 Mar 2008 21:34:46 +0000
Subject: Transfer physical register spill info when load / store folding
 happens.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48246 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/LiveIntervalAnalysis.cpp |  1 +
 lib/CodeGen/VirtRegMap.cpp           |  3 ++-
 lib/CodeGen/VirtRegMap.h             | 17 +++++++++++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 7931804..d7c5544 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -779,6 +779,7 @@ bool LiveIntervals::tryFoldMemoryOperand(MachineInstr* &MI,
       vrm.virtFolded(Reg, MI, fmi, (VirtRegMap::ModRef)MRInfo);
     vrm.transferSpillPts(MI, fmi);
     vrm.transferRestorePts(MI, fmi);
+    vrm.transferEmergencySpills(MI, fmi);
     mi2iMap_.erase(MI);
     i2miMap_[InstrIdx /InstrSlots::NUM] = fmi;
     mi2iMap_[fmi] = InstrIdx;
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index cce36e5..3b6612d 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -35,6 +35,7 @@
 using namespace llvm;
 
 STATISTIC(NumSpills, "Number of register spills");
+STATISTIC(NumPSpills,"Number of physical register spills");
 STATISTIC(NumReMats, "Number of re-materialization");
 STATISTIC(NumDRM   , "Number of re-materializable defs elided");
 STATISTIC(NumStores, "Number of stores added");
@@ -1079,7 +1080,7 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) {
         TII->loadRegFromStackSlot(MBB, next(MII), PhysReg, SS, RC);
         MachineInstr *LoadMI = next(MII);
         VRM.addSpillSlotUse(SS, LoadMI);
-        ++NumSpills;
+        ++NumPSpills;
       }
     }
 
diff --git a/lib/CodeGen/VirtRegMap.h b/lib/CodeGen/VirtRegMap.h
index 7ebf31e..63d5b87 100644
--- a/lib/CodeGen/VirtRegMap.h
+++ b/lib/CodeGen/VirtRegMap.h
@@ -268,6 +268,8 @@ namespace llvm {
       }
     }
 
+    /// @brief - transfer spill point information from one instruction to
+    /// another.
     void transferSpillPts(MachineInstr *Old, MachineInstr *New) {
       std::map<MachineInstr*,std::vector<std::pair<unsigned,bool> > >::iterator
         I = SpillPt2VirtMap.find(Old);
@@ -343,6 +345,21 @@ namespace llvm {
       return EmergencySpillMap[MI];
     }
 
+    /// @brief - transfer emergency spill information from one instruction to
+    /// another.
+    void transferEmergencySpills(MachineInstr *Old, MachineInstr *New) {
+      std::map<MachineInstr*,std::vector<unsigned> >::iterator I =
+        EmergencySpillMap.find(Old);
+      if (I == EmergencySpillMap.end())
+        return;
+      while (!I->second.empty()) {
+        unsigned virtReg = I->second.back();
+        I->second.pop_back();
+        addEmergencySpill(virtReg, New);
+      }
+      EmergencySpillMap.erase(I);
+    }
+
     /// @brief return or get a emergency spill slot for the register class.
     int getEmergencySpillSlot(const TargetRegisterClass *RC);
 
-- 
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