Add support for implicit TLS model used with MS VC runtime.

[oota-llvm.git] / lib / CodeGen / MachineCSE.cpp

diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp
index 5dd51a7944c80e377f7d2211c4a146d4a3d8979e..3031d4588b2ad12922653465e1b884d1513ad3d2 100644 (file)
--- a/lib/CodeGen/MachineCSE.cpp
+++ b/lib/CodeGen/MachineCSE.cpp
@@ -50,7 +50,7 @@ namespace {
     }
 
     virtual bool runOnMachineFunction(MachineFunction &MF);
-    
+
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
       AU.setPreservesCFG();
       MachineFunctionPass::getAnalysisUsage(AU);
@@ -87,6 +87,7 @@ namespace {
                                SmallVector<unsigned,2> &PhysDefs) const;
     bool PhysRegDefsReach(MachineInstr *CSMI, MachineInstr *MI,
                           SmallSet<unsigned,8> &PhysRefs,
+                          SmallVector<unsigned,2> &PhysDefs,
                           bool &NonLocal) const;
     bool isCSECandidate(MachineInstr *MI);
     bool isProfitableToCSE(unsigned CSReg, unsigned Reg,
@@ -102,6 +103,7 @@ namespace {
 } // end anonymous namespace
 
 char MachineCSE::ID = 0;
+char &llvm::MachineCSEID = MachineCSE::ID;
 INITIALIZE_PASS_BEGIN(MachineCSE, "machine-cse",
                 "Machine Common Subexpression Elimination", false, false)
 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
@@ -109,8 +111,6 @@ INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
 INITIALIZE_PASS_END(MachineCSE, "machine-cse",
                 "Machine Common Subexpression Elimination", false, false)
 
-FunctionPass *llvm::createMachineCSEPass() { return new MachineCSE(); }
-
 bool MachineCSE::PerformTrivialCoalescing(MachineInstr *MI,
                                           MachineBasicBlock *MBB) {
   bool Changed = false;
@@ -176,7 +176,7 @@ MachineCSE::isPhysDefTriviallyDead(unsigned Reg,
       SeenDef = true;
     }
     if (SeenDef)
-      // See a def of Reg (or an alias) before encountering any use, it's 
+      // See a def of Reg (or an alias) before encountering any use, it's
       // trivially dead.
       return true;
 
@@ -222,6 +222,7 @@ bool MachineCSE::hasLivePhysRegDefUses(const MachineInstr *MI,
 
 bool MachineCSE::PhysRegDefsReach(MachineInstr *CSMI, MachineInstr *MI,
                                   SmallSet<unsigned,8> &PhysRefs,
+                                  SmallVector<unsigned,2> &PhysDefs,
                                   bool &NonLocal) const {
   // For now conservatively returns false if the common subexpression is
   // not in the same basic block as the given instruction. The only exception
@@ -231,10 +232,16 @@ bool MachineCSE::PhysRegDefsReach(MachineInstr *CSMI, MachineInstr *MI,
 
   bool CrossMBB = false;
   if (CSMBB != MBB) {
-    if (MBB->pred_size() == 1 && *MBB->pred_begin() == CSMBB)
-      CrossMBB = true;
-    else
+    if (MBB->pred_size() != 1 || *MBB->pred_begin() != CSMBB)
       return false;
+
+    for (unsigned i = 0, e = PhysDefs.size(); i != e; ++i) {
+      if (TRI->isInAllocatableClass(PhysDefs[i]))
+        // Avoid extending live range of physical registers unless
+        // they are unallocatable.
+        return false;
+    }
+    CrossMBB = true;
   }
   MachineBasicBlock::const_iterator I = CSMI; I = llvm::next(I);
   MachineBasicBlock::const_iterator E = MI;
@@ -247,6 +254,7 @@ bool MachineCSE::PhysRegDefsReach(MachineInstr *CSMI, MachineInstr *MI,
 
     if (I == EE) {
       assert(CrossMBB && "Reaching end-of-MBB without finding MI?");
+      (void)CrossMBB;
       CrossMBB = false;
       NonLocal = true;
       I = MBB->begin();
@@ -429,7 +437,7 @@ bool MachineCSE::ProcessBlock(MachineBasicBlock *MBB) {
       // in between and the physical register uses were not clobbered.
       unsigned CSVN = VNT.lookup(MI);
       MachineInstr *CSMI = Exps[CSVN];
-      if (PhysRegDefsReach(CSMI, MI, PhysRefs, CrossMBBPhysDef))
+      if (PhysRegDefsReach(CSMI, MI, PhysRefs, PhysDefs, CrossMBBPhysDef))
         FoundCSE = true;
     }