Add a DAGCombine xform to fold away redundant float->double->float conversions around...

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

diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp
index 72474bc3a0b3809dffbe4f976461fc2b1a4b93ef..aa3a10290ba558d0fe9de52165eab4f166bfe37b 100644 (file)
--- a/lib/CodeGen/MachineCSE.cpp
+++ b/lib/CodeGen/MachineCSE.cpp
@@ -107,25 +107,27 @@ bool MachineCSE::PerformTrivialCoalescing(MachineInstr *MI,
     MachineInstr *DefMI = MRI->getVRegDef(Reg);
     if (DefMI->getParent() != MBB)
       continue;
-    unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
-    if (TII->isMoveInstr(*DefMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) &&
-        TargetRegisterInfo::isVirtualRegister(SrcReg) &&
-        !SrcSubIdx && !DstSubIdx) {
-      const TargetRegisterClass *SRC   = MRI->getRegClass(SrcReg);
-      const TargetRegisterClass *RC    = MRI->getRegClass(Reg);
-      const TargetRegisterClass *NewRC = getCommonSubClass(RC, SRC);
-      if (!NewRC)
-        continue;
-      DEBUG(dbgs() << "Coalescing: " << *DefMI);
-      DEBUG(dbgs() << "*** to: " << *MI);
-      MO.setReg(SrcReg);
-      MRI->clearKillFlags(SrcReg);
-      if (NewRC != SRC)
-        MRI->setRegClass(SrcReg, NewRC);
-      DefMI->eraseFromParent();
-      ++NumCoalesces;
-      Changed = true;
-    }
+    if (!DefMI->isCopy())
+      continue;
+    unsigned SrcReg = DefMI->getOperand(1).getReg();
+    if (!TargetRegisterInfo::isVirtualRegister(SrcReg))
+      continue;
+    if (DefMI->getOperand(0).getSubReg() || DefMI->getOperand(1).getSubReg())
+      continue;
+    const TargetRegisterClass *SRC   = MRI->getRegClass(SrcReg);
+    const TargetRegisterClass *RC    = MRI->getRegClass(Reg);
+    const TargetRegisterClass *NewRC = getCommonSubClass(RC, SRC);
+    if (!NewRC)
+      continue;
+    DEBUG(dbgs() << "Coalescing: " << *DefMI);
+    DEBUG(dbgs() << "*** to: " << *MI);
+    MO.setReg(SrcReg);
+    MRI->clearKillFlags(SrcReg);
+    if (NewRC != SRC)
+      MRI->setRegClass(SrcReg, NewRC);
+    DefMI->eraseFromParent();
+    ++NumCoalesces;
+    Changed = true;
   }
 
   return Changed;
@@ -239,19 +241,13 @@ bool MachineCSE::PhysRegDefReaches(MachineInstr *CSMI, MachineInstr *MI,
   return false;
 }
 
-static bool isCopy(const MachineInstr *MI, const TargetInstrInfo *TII) {
-  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
-  return TII->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) ||
-    MI->isExtractSubreg() || MI->isInsertSubreg() || MI->isSubregToReg();
-}
-
 bool MachineCSE::isCSECandidate(MachineInstr *MI) {
   if (MI->isLabel() || MI->isPHI() || MI->isImplicitDef() ||
       MI->isKill() || MI->isInlineAsm() || MI->isDebugValue())
     return false;
 
   // Ignore copies.
-  if (isCopy(MI, TII))
+  if (MI->isCopyLike())
     return false;
 
   // Ignore stuff that we obviously can't move.
@@ -307,7 +303,7 @@ bool MachineCSE::isProfitableToCSE(unsigned CSReg, unsigned Reg,
            E = MRI->use_nodbg_end(); I != E; ++I) {
       MachineInstr *Use = &*I;
       // Ignore copies.
-      if (!isCopy(Use, TII)) {
+      if (!Use->isCopyLike()) {
         HasNonCopyUse = true;
         break;
       }
@@ -363,7 +359,7 @@ bool MachineCSE::ProcessBlock(MachineBasicBlock *MBB) {
       // Look for trivial copy coalescing opportunities.
       if (PerformTrivialCoalescing(MI, MBB)) {
         // After coalescing MI itself may become a copy.
-        if (isCopy(MI, TII))
+        if (MI->isCopyLike())
           continue;
         FoundCSE = VNT.count(MI);
       }