Remove unused but set variable flagged by GCC.

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

diff --git a/lib/CodeGen/MachineCopyPropagation.cpp b/lib/CodeGen/MachineCopyPropagation.cpp
index 565efb3898c915bf49d7cba84dc1b1995bf30ed8..bac3aa2c155eef46f0a712488cce35dcdef88000 100644 (file)
--- a/lib/CodeGen/MachineCopyPropagation.cpp
+++ b/lib/CodeGen/MachineCopyPropagation.cpp
@@ -22,7 +22,6 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
@@ -44,9 +43,12 @@ namespace {
     virtual bool runOnMachineFunction(MachineFunction &MF);
 
   private:
+    typedef SmallVector<unsigned, 4> DestList;
+    typedef DenseMap<unsigned, DestList> SourceMap;
+
     void SourceNoLongerAvailable(unsigned Reg,
-                                 DenseMap<unsigned, DenseSet<unsigned> > &SrcMap,
-                               DenseMap<unsigned, MachineInstr*> &AvailCopyMap);
+                                 SourceMap &SrcMap,
+                                 DenseMap<unsigned, MachineInstr*> &AvailCopyMap);
     bool CopyPropagateBlock(MachineBasicBlock &MBB);
   };
 }
@@ -58,30 +60,18 @@ INITIALIZE_PASS(MachineCopyPropagation, "machine-cp",
 
 void
 MachineCopyPropagation::SourceNoLongerAvailable(unsigned Reg,
-                              DenseMap<unsigned, DenseSet<unsigned> > &SrcMap,
+                              SourceMap &SrcMap,
                               DenseMap<unsigned, MachineInstr*> &AvailCopyMap) {
-  DenseMap<unsigned, DenseSet<unsigned> >::iterator SI = SrcMap.find(Reg);
-  if (SI != SrcMap.end()) {
-    const DenseSet<unsigned>& Defs = SI->second;
-    for (DenseSet<unsigned>::const_iterator I = Defs.begin(), E = Defs.end();
-         I != E; ++I) {
-      unsigned MappedDef = *I;
-      // Source of copy is no longer available for propagation.
-      if (AvailCopyMap.erase(MappedDef)) {
-        for (const uint16_t *SR = TRI->getSubRegisters(MappedDef); *SR; ++SR)
-          AvailCopyMap.erase(*SR);
-      }
-    }
-  }
-  for (const uint16_t *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
-    SI = SrcMap.find(*AS);
+  for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) {
+    SourceMap::iterator SI = SrcMap.find(*AI);
     if (SI != SrcMap.end()) {
-      const DenseSet<unsigned>& Defs = SI->second;
-      for (DenseSet<unsigned>::const_iterator I = Defs.begin(), E = Defs.end();
+      const DestList& Defs = SI->second;
+      for (DestList::const_iterator I = Defs.begin(), E = Defs.end();
            I != E; ++I) {
         unsigned MappedDef = *I;
+        // Source of copy is no longer available for propagation.
         if (AvailCopyMap.erase(MappedDef)) {
-          for (const uint16_t *SR = TRI->getSubRegisters(MappedDef); *SR; ++SR)
+          for (MCSubRegIterator SR(MappedDef, TRI); SR.isValid(); ++SR)
             AvailCopyMap.erase(*SR);
         }
       }
@@ -137,7 +127,7 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
   SmallSetVector<MachineInstr*, 8> MaybeDeadCopies;  // Candidates for deletion
   DenseMap<unsigned, MachineInstr*> AvailCopyMap;    // Def -> available copies map
   DenseMap<unsigned, MachineInstr*> CopyMap;         // Def -> copies map
-  DenseMap<unsigned, DenseSet<unsigned> > SrcMap; // Src -> Def map
+  SourceMap SrcMap; // Src -> Def map
 
   bool Changed = false;
   for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ) {
@@ -186,11 +176,8 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
       }
 
       // If Src is defined by a previous copy, it cannot be eliminated.
-      CI = CopyMap.find(Src);
-      if (CI != CopyMap.end())
-        MaybeDeadCopies.remove(CI->second);
-      for (const uint16_t *AS = TRI->getAliasSet(Src); *AS; ++AS) {
-        CI = CopyMap.find(*AS);
+      for (MCRegAliasIterator AI(Src, TRI, true); AI.isValid(); ++AI) {
+        CI = CopyMap.find(*AI);
         if (CI != CopyMap.end())
           MaybeDeadCopies.remove(CI->second);
       }
@@ -209,20 +196,23 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
 
       // Remember Def is defined by the copy.
       // ... Make sure to clear the def maps of aliases first.
-      for (const uint16_t *AS = TRI->getAliasSet(Def); *AS; ++AS) {
-        CopyMap.erase(*AS);
-        AvailCopyMap.erase(*AS);
+      for (MCRegAliasIterator AI(Def, TRI, false); AI.isValid(); ++AI) {
+        CopyMap.erase(*AI);
+        AvailCopyMap.erase(*AI);
       }
       CopyMap[Def] = MI;
       AvailCopyMap[Def] = MI;
-      for (const uint16_t *SR = TRI->getSubRegisters(Def); *SR; ++SR) {
+      for (MCSubRegIterator SR(Def, TRI); SR.isValid(); ++SR) {
         CopyMap[*SR] = MI;
         AvailCopyMap[*SR] = MI;
       }
 
       // Remember source that's copied to Def. Once it's clobbered, then
       // it's no longer available for copy propagation.
-      SrcMap[Src].insert(Def);
+      if (std::find(SrcMap[Src].begin(), SrcMap[Src].end(), Def) ==
+          SrcMap[Src].end()) {
+        SrcMap[Src].push_back(Def);
+      }
 
       continue;
     }
@@ -251,11 +241,8 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
 
       // If 'Reg' is defined by a copy, the copy is no longer a candidate
       // for elimination.
-      DenseMap<unsigned, MachineInstr*>::iterator CI = CopyMap.find(Reg);
-      if (CI != CopyMap.end())
-        MaybeDeadCopies.remove(CI->second);
-      for (const uint16_t *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
-        CI = CopyMap.find(*AS);
+      for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) {
+        DenseMap<unsigned, MachineInstr*>::iterator CI = CopyMap.find(*AI);
         if (CI != CopyMap.end())
           MaybeDeadCopies.remove(CI->second);
       }
@@ -291,11 +278,9 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
       unsigned Reg = Defs[i];
 
       // No longer defined by a copy.
-      CopyMap.erase(Reg);
-      AvailCopyMap.erase(Reg);
-      for (const uint16_t *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
-        CopyMap.erase(*AS);
-        AvailCopyMap.erase(*AS);
+      for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) {
+        CopyMap.erase(*AI);
+        AvailCopyMap.erase(*AI);
       }
 
       // If 'Reg' is previously source of a copy, it is no longer available for