1 files changed, 4 insertions, 96 deletions

diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
index a9813e534c5f..e9f8d43fe643 100644
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -54,8 +54,6 @@ static void doSpillCalleeSavedRegs(MachineFunction &MF, RegScavenger *RS,
                                    const MBBVector &SaveBlocks,
                                    const MBBVector &RestoreBlocks);
 
-static void doScavengeFrameVirtualRegs(MachineFunction &MF, RegScavenger *RS);
-
 namespace {
 class PEI : public MachineFunctionPass {
 public:
@@ -84,7 +82,7 @@ private:
                      const MBBVector &SaveBlocks,
                      const MBBVector &RestoreBlocks)>
       SpillCalleeSavedRegisters;
-  std::function<void(MachineFunction &MF, RegScavenger *RS)>
+  std::function<void(MachineFunction &MF, RegScavenger &RS)>
       ScavengeFrameVirtualRegs;
 
   bool UsesCalleeSaves = false;
@@ -142,7 +140,6 @@ MachineFunctionPass *llvm::createPrologEpilogInserterPass() {
   return new PEI();
 }
 
-STATISTIC(NumScavengedRegs, "Number of frame index regs scavenged");
 STATISTIC(NumBytesStackSpace,
           "Number of bytes used for stack in all functions");
 
@@ -168,10 +165,10 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) {
       SpillCalleeSavedRegisters = [](MachineFunction &, RegScavenger *,
                                      unsigned &, unsigned &, const MBBVector &,
                                      const MBBVector &) {};
-      ScavengeFrameVirtualRegs = [](MachineFunction &, RegScavenger *) {};
+      ScavengeFrameVirtualRegs = [](MachineFunction &, RegScavenger &) {};
     } else {
       SpillCalleeSavedRegisters = doSpillCalleeSavedRegs;
-      ScavengeFrameVirtualRegs = doScavengeFrameVirtualRegs;
+      ScavengeFrameVirtualRegs = scavengeFrameVirtualRegs;
       UsesCalleeSaves = true;
     }
   }
@@ -222,7 +219,7 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) {
   // post-pass, scavenge the virtual registers that frame index elimination
   // inserted.
   if (TRI->requiresRegisterScavenging(Fn) && FrameIndexVirtualScavenging) {
-      ScavengeFrameVirtualRegs(Fn, RS);
+      ScavengeFrameVirtualRegs(Fn, *RS);
 
       // Clear any vregs created by virtual scavenging.
       Fn.getRegInfo().clearVirtRegs();
@@ -1153,92 +1150,3 @@ void PEI::replaceFrameIndices(MachineBasicBlock *BB, MachineFunction &Fn,
       RS->forward(MI);
   }
 }
-
-/// doScavengeFrameVirtualRegs - Replace all frame index virtual registers
-/// with physical registers. Use the register scavenger to find an
-/// appropriate register to use.
-///
-/// FIXME: Iterating over the instruction stream is unnecessary. We can simply
-/// iterate over the vreg use list, which at this point only contains machine
-/// operands for which eliminateFrameIndex need a new scratch reg.
-static void
-doScavengeFrameVirtualRegs(MachineFunction &MF, RegScavenger *RS) {
-  // Run through the instructions and find any virtual registers.
-  MachineRegisterInfo &MRI = MF.getRegInfo();
-  for (MachineBasicBlock &MBB : MF) {
-    RS->enterBasicBlock(MBB);
-
-    int SPAdj = 0;
-
-    // The instruction stream may change in the loop, so check MBB.end()
-    // directly.
-    for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end(); ) {
-      // We might end up here again with a NULL iterator if we scavenged a
-      // register for which we inserted spill code for definition by what was
-      // originally the first instruction in MBB.
-      if (I == MachineBasicBlock::iterator(nullptr))
-        I = MBB.begin();
-
-      const MachineInstr &MI = *I;
-      MachineBasicBlock::iterator J = std::next(I);
-      MachineBasicBlock::iterator P =
-                         I == MBB.begin() ? MachineBasicBlock::iterator(nullptr)
-                                          : std::prev(I);
-
-      // RS should process this instruction before we might scavenge at this
-      // location. This is because we might be replacing a virtual register
-      // defined by this instruction, and if so, registers killed by this
-      // instruction are available, and defined registers are not.
-      RS->forward(I);
-
-      for (const MachineOperand &MO : MI.operands()) {
-        if (!MO.isReg())
-          continue;
-        unsigned Reg = MO.getReg();
-        if (!TargetRegisterInfo::isVirtualRegister(Reg))
-          continue;
-
-        // When we first encounter a new virtual register, it
-        // must be a definition.
-        assert(MO.isDef() && "frame index virtual missing def!");
-        // Scavenge a new scratch register
-        const TargetRegisterClass *RC = MRI.getRegClass(Reg);
-        unsigned ScratchReg = RS->scavengeRegister(RC, J, SPAdj);
-
-        ++NumScavengedRegs;
-
-        // Replace this reference to the virtual register with the
-        // scratch register.
-        assert(ScratchReg && "Missing scratch register!");
-        MRI.replaceRegWith(Reg, ScratchReg);
-
-        // Because this instruction was processed by the RS before this
-        // register was allocated, make sure that the RS now records the
-        // register as being used.
-        RS->setRegUsed(ScratchReg);
-      }
-
-      // If the scavenger needed to use one of its spill slots, the
-      // spill code will have been inserted in between I and J. This is a
-      // problem because we need the spill code before I: Move I to just
-      // prior to J.
-      if (I != std::prev(J)) {
-        MBB.splice(J, &MBB, I);
-
-        // Before we move I, we need to prepare the RS to visit I again.
-        // Specifically, RS will assert if it sees uses of registers that
-        // it believes are undefined. Because we have already processed
-        // register kills in I, when it visits I again, it will believe that
-        // those registers are undefined. To avoid this situation, unprocess
-        // the instruction I.
-        assert(RS->getCurrentPosition() == I &&
-          "The register scavenger has an unexpected position");
-        I = P;
-        RS->unprocess(P);
-      } else
-        ++I;
-    }
-  }
-
-  MF.getProperties().set(MachineFunctionProperties::Property::NoVRegs);
-}