diff options
| -rw-r--r-- | include/llvm/CodeGen/LiveIntervalAnalysis.h | 1 | ||||
| -rw-r--r-- | lib/CodeGen/LiveIntervalAnalysis.cpp | 37 |
2 files changed, 37 insertions, 1 deletions
diff --git a/include/llvm/CodeGen/LiveIntervalAnalysis.h b/include/llvm/CodeGen/LiveIntervalAnalysis.h index a344b1f..fe22d8a 100644 --- a/include/llvm/CodeGen/LiveIntervalAnalysis.h +++ b/include/llvm/CodeGen/LiveIntervalAnalysis.h @@ -375,6 +375,7 @@ namespace llvm { void computeLiveInRegUnits(); void computeRegUnitInterval(LiveInterval*); + void computeVirtRegInterval(LiveInterval*); class HMEditor; }; diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp index 819707f..bc0ec15 100644 --- a/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -27,6 +27,7 @@ #include "llvm/Target/TargetRegisterInfo.h" #include "llvm/Target/TargetInstrInfo.h" #include "llvm/Target/TargetMachine.h" +#include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" @@ -38,6 +39,11 @@ #include <cmath> using namespace llvm; +// Switch to the new experimental algorithm for computing live intervals. +static cl::opt<bool> +NewLiveIntervals("new-live-intervals", cl::Hidden, + cl::desc("Use new algorithm forcomputing live intervals")); + char LiveIntervals::ID = 0; INITIALIZE_PASS_BEGIN(LiveIntervals, "liveintervals", "Live Interval Analysis", false, false) @@ -105,7 +111,25 @@ bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) { AllocatableRegs = TRI->getAllocatableSet(fn); ReservedRegs = TRI->getReservedRegs(fn); - computeIntervals(); + // Allocate space for all virtual registers. + VirtRegIntervals.resize(MRI->getNumVirtRegs()); + + if (NewLiveIntervals) { + // This is the new way of computing live intervals. + // It is independent of LiveVariables, and it can run at any time. + for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) { + unsigned Reg = TargetRegisterInfo::index2VirtReg(i); + if (MRI->reg_nodbg_empty(Reg)) + continue; + LiveInterval *LI = createInterval(Reg); + VirtRegIntervals[Reg] = LI; + computeVirtRegInterval(LI); + } + } else { + // This is the old way of computing live intervals. + // It depends on LiveVariables. + computeIntervals(); + } computeLiveInRegUnits(); DEBUG(dump()); @@ -442,6 +466,17 @@ LiveInterval* LiveIntervals::createInterval(unsigned reg) { } +/// computeVirtRegInterval - Compute the live interval of a virtual register, +/// based on defs and uses. +void LiveIntervals::computeVirtRegInterval(LiveInterval *LI) { + assert(LRCalc && "LRCalc not initialized."); + assert(LI->empty() && "Should only compute empty intervals."); + LRCalc->reset(MF, getSlotIndexes(), DomTree, &getVNInfoAllocator()); + LRCalc->createDeadDefs(LI); + LRCalc->extendToUses(LI); +} + + //===----------------------------------------------------------------------===// // Register Unit Liveness //===----------------------------------------------------------------------===// |