Commit 71c380f6 authored by Jakob Stoklund Olesen's avatar Jakob Stoklund Olesen
Browse files

Let shrinkToUses optionally return a list of now dead machine instructions. 

llvm-svn: 127192
parent 6258c53e

llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h

+3 −1
Original line number Diff line number Diff line
@@ -159,7 +159,9 @@ namespace llvm { 
    /// range to just the remaining uses. This method does not compute reaching

    /// defs for new uses, and it doesn't remove dead defs.

    /// Dead PHIDef values are marked as unused.

    void shrinkToUses(LiveInterval *li);

    /// New dead machine instructions are added to the dead vector.

    void shrinkToUses(LiveInterval *li,

                      SmallVectorImpl<MachineInstr*> *dead = 0);



    // Interval removal

llvm/lib/CodeGen/LiveIntervalAnalysis.cpp

+6 −1
Original line number Diff line number Diff line
@@ -746,7 +746,8 @@ LiveInterval* LiveIntervals::dupInterval(LiveInterval *li) { 
/// shrinkToUses - After removing some uses of a register, shrink its live

/// range to just the remaining uses. This method does not compute reaching

/// defs for new uses, and it doesn't remove dead defs.

void LiveIntervals::shrinkToUses(LiveInterval *li) {

void LiveIntervals::shrinkToUses(LiveInterval *li,

                                 SmallVectorImpl<MachineInstr*> *dead) {

  DEBUG(dbgs() << "Shrink: " << *li << '\n');

  assert(TargetRegisterInfo::isVirtualRegister(li->reg)

         && "Can't only shrink physical registers");
@@ -852,6 +853,10 @@ void LiveIntervals::shrinkToUses(LiveInterval *li) { 
      MachineInstr *MI = getInstructionFromIndex(VNI->def);

      assert(MI && "No instruction defining live value");

      MI->addRegisterDead(li->reg, tri_);

      if (dead && MI->allDefsAreDead()) {

        DEBUG(dbgs() << "All defs dead: " << *MI);

        dead->push_back(MI);

      }

    }

  }