diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/RegisterScavenging.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/RegisterScavenging.cpp | 34 |
1 files changed, 17 insertions, 17 deletions
diff --git a/contrib/llvm/lib/CodeGen/RegisterScavenging.cpp b/contrib/llvm/lib/CodeGen/RegisterScavenging.cpp index 43b3fb6..a2580b8 100644 --- a/contrib/llvm/lib/CodeGen/RegisterScavenging.cpp +++ b/contrib/llvm/lib/CodeGen/RegisterScavenging.cpp @@ -21,7 +21,9 @@ #include "llvm/CodeGen/MachineBasicBlock.h" #include "llvm/CodeGen/MachineInstr.h" #include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetRegisterInfo.h" #include "llvm/Target/TargetInstrInfo.h" #include "llvm/Target/TargetMachine.h" @@ -226,19 +228,14 @@ void RegScavenger::getRegsUsed(BitVector &used, bool includeReserved) { used = ~RegsAvailable & ~ReservedRegs; } -/// CreateRegClassMask - Set the bits that represent the registers in the -/// TargetRegisterClass. -static void CreateRegClassMask(const TargetRegisterClass *RC, BitVector &Mask) { - for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end(); I != E; - ++I) - Mask.set(*I); -} - unsigned RegScavenger::FindUnusedReg(const TargetRegisterClass *RC) const { for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end(); I != E; ++I) - if (!isAliasUsed(*I)) + if (!isAliasUsed(*I)) { + DEBUG(dbgs() << "Scavenger found unused reg: " << TRI->getName(*I) << + "\n"); return *I; + } return 0; } @@ -325,11 +322,9 @@ unsigned RegScavenger::findSurvivorReg(MachineBasicBlock::iterator StartMI, unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC, MachineBasicBlock::iterator I, int SPAdj) { - // Mask off the registers which are not in the TargetRegisterClass. - BitVector Candidates(NumPhysRegs, false); - CreateRegClassMask(RC, Candidates); - // Do not include reserved registers. - Candidates ^= ReservedRegs & Candidates; + // Consider all allocatable registers in the register class initially + BitVector Candidates = + TRI->getAllocatableSet(*I->getParent()->getParent(), RC); // Exclude all the registers being used by the instruction. for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) { @@ -349,8 +344,10 @@ unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC, unsigned SReg = findSurvivorReg(I, Candidates, 25, UseMI); // If we found an unused register there is no reason to spill it. - if (!isAliasUsed(SReg)) + if (!isAliasUsed(SReg)) { + DEBUG(dbgs() << "Scavenged register: " << TRI->getName(SReg) << "\n"); return SReg; + } assert(ScavengedReg == 0 && "Scavenger slot is live, unable to scavenge another register!"); @@ -366,12 +363,12 @@ unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC, "Cannot scavenge register without an emergency spill slot!"); TII->storeRegToStackSlot(*MBB, I, SReg, true, ScavengingFrameIndex, RC,TRI); MachineBasicBlock::iterator II = prior(I); - TRI->eliminateFrameIndex(II, SPAdj, NULL, this); + TRI->eliminateFrameIndex(II, SPAdj, this); // Restore the scavenged register before its use (or first terminator). TII->loadRegFromStackSlot(*MBB, UseMI, SReg, ScavengingFrameIndex, RC, TRI); II = prior(UseMI); - TRI->eliminateFrameIndex(II, SPAdj, NULL, this); + TRI->eliminateFrameIndex(II, SPAdj, this); } ScavengeRestore = prior(UseMI); @@ -380,5 +377,8 @@ unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC, // ScavengedReg = SReg; ScavengedRC = RC; + DEBUG(dbgs() << "Scavenged register (with spill): " << TRI->getName(SReg) << + "\n"); + return SReg; } |
