Fix some fixme's in #if 0'd code by making it dependent on the structural

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

diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp
index 311c0e7ffc90832fa267e865aca0747d8c14296f..e5d3a48babdf48e5cfef485225fb203d9e3590ad 100644 (file)
--- a/lib/CodeGen/RegAllocLocal.cpp
+++ b/lib/CodeGen/RegAllocLocal.cpp
@@ -25,6 +25,8 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Compiler.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/IndexedMap.h"
 #include "llvm/ADT/SmallSet.h"
@@ -151,6 +153,7 @@ namespace {
     }
 
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+      AU.setPreservesCFG();
       AU.addRequiredID(PHIEliminationID);
       AU.addRequiredID(TwoAddressInstructionPassID);
       MachineFunctionPass::getAnalysisUsage(AU);
@@ -464,7 +467,7 @@ unsigned RALocal::getReg(MachineBasicBlock &MBB, MachineInstr *I,
 }
 
 
-/// reloadVirtReg - This method transforms the specified specified virtual
+/// reloadVirtReg - This method transforms the specified virtual
 /// register use to refer to a physical register.  This method may do this in
 /// one of several ways: if the register is available in a physical register
 /// already, it uses that physical register.  If the value is not in a physical
@@ -517,24 +520,28 @@ MachineInstr *RALocal::reloadVirtReg(MachineBasicBlock &MBB, MachineInstr *MI,
   getVirtRegLastUse(VirtReg) = std::make_pair(MI, OpNum);
 
   if (!ReloadedRegs.insert(PhysReg)) {
-    cerr << "Ran out of registers during register allocation!\n";
+    std::string msg;
+    raw_string_ostream Msg(msg);
+    Msg << "Ran out of registers during register allocation!";
     if (MI->getOpcode() == TargetInstrInfo::INLINEASM) {
-      cerr << "Please check your inline asm statement for invalid "
+      Msg << "\nPlease check your inline asm statement for invalid "
            << "constraints:\n";
-      MI->print(cerr.stream(), TM);
+      MI->print(Msg, TM);
     }
-    exit(1);
+    llvm_report_error(Msg.str());
   }
   for (const unsigned *SubRegs = TRI->getSubRegisters(PhysReg);
        *SubRegs; ++SubRegs) {
     if (!ReloadedRegs.insert(*SubRegs)) {
-      cerr << "Ran out of registers during register allocation!\n";
+      std::string msg;
+      raw_string_ostream Msg(msg);
+      Msg << "Ran out of registers during register allocation!";
       if (MI->getOpcode() == TargetInstrInfo::INLINEASM) {
-        cerr << "Please check your inline asm statement for invalid "
+        Msg << "\nPlease check your inline asm statement for invalid "
              << "constraints:\n";
-        MI->print(cerr.stream(), TM);
+        MI->print(Msg, TM);
       }
-      exit(1);
+      llvm_report_error(Msg.str());
     }
   }
 
@@ -708,7 +715,7 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) {
   MachineBasicBlock::iterator MII = MBB.begin();
   
   DEBUG(const BasicBlock *LBB = MBB.getBasicBlock();
-        if (LBB) DOUT << "\nStarting RegAlloc of BB: " << LBB->getName());
+        if (LBB) errs() << "\nStarting RegAlloc of BB: " << LBB->getName());
 
   // Add live-in registers as active.
   for (MachineBasicBlock::livein_iterator I = MBB.livein_begin(),
@@ -981,10 +988,12 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) {
       }
     }
     
-    // Finally, if this is a noop copy instruction, zap it.
+    // Finally, if this is a noop copy instruction, zap it.  (Except that if
+    // the copy is dead, it must be kept to avoid messing up liveness info for
+    // the register scavenger.  See pr4100.)
     unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
     if (TII->isMoveInstr(*MI, SrcReg, DstReg, SrcSubReg, DstSubReg) &&
-        SrcReg == DstReg)
+        SrcReg == DstReg && DeadDefs.empty())
       MBB.erase(MI);
   }