diff options
| -rw-r--r-- | lib/CodeGen/RegisterScavenging.cpp | 42 |
1 files changed, 39 insertions, 3 deletions
diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp index 06baa81c03..253bc23d45 100644 --- a/lib/CodeGen/RegisterScavenging.cpp +++ b/lib/CodeGen/RegisterScavenging.cpp @@ -25,6 +25,24 @@ #include "llvm/ADT/STLExtras.h" using namespace llvm; +/// setUsed - Set the register and its sub-registers as being used. +void RegScavenger::setUsed(unsigned Reg) { + RegsAvailable.reset(Reg); + + for (const unsigned *SubRegs = RegInfo->getSubRegisters(Reg); + unsigned SubReg = *SubRegs; ++SubRegs) + RegsAvailable.reset(SubReg); +} + +/// setUnused - Set the register and its sub-registers as being unused. +void RegScavenger::setUnused(unsigned Reg) { + RegsAvailable.set(Reg); + + for (const unsigned *SubRegs = RegInfo->getSubRegisters(Reg); + unsigned SubReg = *SubRegs; ++SubRegs) + RegsAvailable.set(SubReg); +} + void RegScavenger::enterBasicBlock(MachineBasicBlock *mbb) { const MachineFunction &MF = *mbb->getParent(); const TargetMachine &TM = MF.getTarget(); @@ -105,9 +123,10 @@ void RegScavenger::forward() { const MachineOperand &MO = MI->getOperand(i); if (!MO.isRegister() || !MO.isUse()) continue; + unsigned Reg = MO.getReg(); - if (Reg == 0) - continue; + if (Reg == 0) continue; + if (!isUsed(Reg)) { // Register has been scavenged. Restore it! if (Reg != ScavengedReg) @@ -115,9 +134,16 @@ void RegScavenger::forward() { else restoreScavengedReg(); } - if (MO.isKill() && !isReserved(Reg)) + + if (MO.isKill() && !isReserved(Reg)) { ChangedRegs.set(Reg); + + for (const unsigned *SubRegs = RegInfo->getSubRegisters(Reg); + unsigned SubReg = *SubRegs; ++SubRegs) + ChangedRegs.set(SubReg); + } } + // Change states of all registers after all the uses are processed to guard // against multiple uses. setUnused(ChangedRegs); @@ -125,19 +151,24 @@ void RegScavenger::forward() { // Process defs. for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { const MachineOperand &MO = MI->getOperand(i); + if (!MO.isRegister() || !MO.isDef()) continue; + unsigned Reg = MO.getReg(); + // If it's dead upon def, then it is now free. if (MO.isDead()) { setUnused(Reg); continue; } + // Skip two-address destination operand. if (TID.findTiedToSrcOperand(i) != -1) { assert(isUsed(Reg) && "Using an undefined register!"); continue; } + assert((isUnused(Reg) || isReserved(Reg)) && "Re-defining a live register!"); setUsed(Reg); @@ -177,6 +208,11 @@ void RegScavenger::backward() { continue; assert(isUnused(Reg) || isReserved(Reg)); ChangedRegs.set(Reg); + + // Set the sub-registers as "used". + for (const unsigned *SubRegs = RegInfo->getSubRegisters(Reg); + unsigned SubReg = *SubRegs; ++SubRegs) + ChangedRegs.set(SubReg); } setUsed(ChangedRegs); } |