1 files changed, 152 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/LiveRegMatrix.cpp b/contrib/llvm/lib/CodeGen/LiveRegMatrix.cpp
new file mode 100644
index 000000000000..cdb17768129c
--- /dev/null
+++ b/contrib/llvm/lib/CodeGen/LiveRegMatrix.cpp
@@ -0,0 +1,152 @@
+//===-- LiveRegMatrix.cpp - Track register interference -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the LiveRegMatrix analysis pass.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "regalloc"
+#include "LiveRegMatrix.h"
+#include "VirtRegMap.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+STATISTIC(NumAssigned   , "Number of registers assigned");
+STATISTIC(NumUnassigned , "Number of registers unassigned");
+
+char LiveRegMatrix::ID = 0;
+INITIALIZE_PASS_BEGIN(LiveRegMatrix, "liveregmatrix",
+                      "Live Register Matrix", false, false)
+INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
+INITIALIZE_PASS_DEPENDENCY(VirtRegMap)
+INITIALIZE_PASS_END(LiveRegMatrix, "liveregmatrix",
+                    "Live Register Matrix", false, false)
+
+LiveRegMatrix::LiveRegMatrix() : MachineFunctionPass(ID),
+  UserTag(0), RegMaskTag(0), RegMaskVirtReg(0) {}
+
+void LiveRegMatrix::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+  AU.addRequiredTransitive<LiveIntervals>();
+  AU.addRequiredTransitive<VirtRegMap>();
+  MachineFunctionPass::getAnalysisUsage(AU);
+}
+
+bool LiveRegMatrix::runOnMachineFunction(MachineFunction &MF) {
+  TRI = MF.getTarget().getRegisterInfo();
+  MRI = &MF.getRegInfo();
+  LIS = &getAnalysis<LiveIntervals>();
+  VRM = &getAnalysis<VirtRegMap>();
+
+  unsigned NumRegUnits = TRI->getNumRegUnits();
+  if (NumRegUnits != Matrix.size())
+    Queries.reset(new LiveIntervalUnion::Query[NumRegUnits]);
+  Matrix.init(LIUAlloc, NumRegUnits);
+
+  // Make sure no stale queries get reused.
+  invalidateVirtRegs();
+  return false;
+}
+
+void LiveRegMatrix::releaseMemory() {
+  for (unsigned i = 0, e = Matrix.size(); i != e; ++i) {
+    Matrix[i].clear();
+    Queries[i].clear();
+  }
+}
+
+void LiveRegMatrix::assign(LiveInterval &VirtReg, unsigned PhysReg) {
+  DEBUG(dbgs() << "assigning " << PrintReg(VirtReg.reg, TRI)
+               << " to " << PrintReg(PhysReg, TRI) << ':');
+  assert(!VRM->hasPhys(VirtReg.reg) && "Duplicate VirtReg assignment");
+  VRM->assignVirt2Phys(VirtReg.reg, PhysReg);
+  MRI->setPhysRegUsed(PhysReg);
+  for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units) {
+    DEBUG(dbgs() << ' ' << PrintRegUnit(*Units, TRI));
+    Matrix[*Units].unify(VirtReg);
+  }
+  ++NumAssigned;
+  DEBUG(dbgs() << '\n');
+}
+
+void LiveRegMatrix::unassign(LiveInterval &VirtReg) {
+  unsigned PhysReg = VRM->getPhys(VirtReg.reg);
+  DEBUG(dbgs() << "unassigning " << PrintReg(VirtReg.reg, TRI)
+               << " from " << PrintReg(PhysReg, TRI) << ':');
+  VRM->clearVirt(VirtReg.reg);
+  for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units) {
+    DEBUG(dbgs() << ' ' << PrintRegUnit(*Units, TRI));
+    Matrix[*Units].extract(VirtReg);
+  }
+  ++NumUnassigned;
+  DEBUG(dbgs() << '\n');
+}
+
+bool LiveRegMatrix::checkRegMaskInterference(LiveInterval &VirtReg,
+                                             unsigned PhysReg) {
+  // Check if the cached information is valid.
+  // The same BitVector can be reused for all PhysRegs.
+  // We could cache multiple VirtRegs if it becomes necessary.
+  if (RegMaskVirtReg != VirtReg.reg || RegMaskTag != UserTag) {
+    RegMaskVirtReg = VirtReg.reg;
+    RegMaskTag = UserTag;
+    RegMaskUsable.clear();
+    LIS->checkRegMaskInterference(VirtReg, RegMaskUsable);
+  }
+
+  // The BitVector is indexed by PhysReg, not register unit.
+  // Regmask interference is more fine grained than regunits.
+  // For example, a Win64 call can clobber %ymm8 yet preserve %xmm8.
+  return !RegMaskUsable.empty() && (!PhysReg || !RegMaskUsable.test(PhysReg));
+}
+
+bool LiveRegMatrix::checkRegUnitInterference(LiveInterval &VirtReg,
+                                             unsigned PhysReg) {
+  if (VirtReg.empty())
+    return false;
+  for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units)
+    if (VirtReg.overlaps(LIS->getRegUnit(*Units)))
+      return true;
+  return false;
+}
+
+LiveIntervalUnion::Query &LiveRegMatrix::query(LiveInterval &VirtReg,
+                                               unsigned RegUnit) {
+  LiveIntervalUnion::Query &Q = Queries[RegUnit];
+  Q.init(UserTag, &VirtReg, &Matrix[RegUnit]);
+  return Q;
+}
+
+LiveRegMatrix::InterferenceKind
+LiveRegMatrix::checkInterference(LiveInterval &VirtReg, unsigned PhysReg) {
+  if (VirtReg.empty())
+    return IK_Free;
+
+  // Regmask interference is the fastest check.
+  if (checkRegMaskInterference(VirtReg, PhysReg))
+    return IK_RegMask;
+
+  // Check for fixed interference.
+  if (checkRegUnitInterference(VirtReg, PhysReg))
+    return IK_RegUnit;
+
+  // Check the matrix for virtual register interference.
+  for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units)
+    if (query(VirtReg, *Units).checkInterference())
+      return IK_VirtReg;
+
+  return IK_Free;
+}