Issue description:

[oota-llvm.git] / lib / CodeGen / VirtRegMap.cpp

diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index 45c7dd0cc80a2cd1cc6550d18419b91bf93c0098..a69a8169d30555165d04db5b388d0d3a24f8c32a 100644 (file)
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -19,8 +19,8 @@
 #define DEBUG_TYPE "regalloc"
 #include "VirtRegMap.h"
 #include "LiveDebugVariables.h"
-#include "llvm/Function.h"
 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/LiveStackAnalysis.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
@@ -127,9 +127,11 @@ void VirtRegMap::print(raw_ostream &OS, const Module*) const {
   OS << '\n';
 }
 
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 void VirtRegMap::dump() const {
   print(dbgs());
 }
+#endif
 
 //===----------------------------------------------------------------------===//
 //                              VirtRegRewriter
@@ -170,6 +172,7 @@ INITIALIZE_PASS_BEGIN(VirtRegRewriter, "virtregrewriter",
 INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
 INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
 INITIALIZE_PASS_DEPENDENCY(LiveDebugVariables)
+INITIALIZE_PASS_DEPENDENCY(LiveStacks)
 INITIALIZE_PASS_DEPENDENCY(VirtRegMap)
 INITIALIZE_PASS_END(VirtRegRewriter, "virtregrewriter",
                     "Virtual Register Rewriter", false, false)
@@ -182,6 +185,8 @@ void VirtRegRewriter::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<SlotIndexes>();
   AU.addPreserved<SlotIndexes>();
   AU.addRequired<LiveDebugVariables>();
+  AU.addRequired<LiveStacks>();
+  AU.addPreserved<LiveStacks>();
   AU.addRequired<VirtRegMap>();
   MachineFunctionPass::getAnalysisUsage(AU);
 }
@@ -197,11 +202,14 @@ bool VirtRegRewriter::runOnMachineFunction(MachineFunction &fn) {
   VRM = &getAnalysis<VirtRegMap>();
   DEBUG(dbgs() << "********** REWRITE VIRTUAL REGISTERS **********\n"
                << "********** Function: "
-               << MF->getFunction()->getName() << '\n');
+               << MF->getName() << '\n');
   DEBUG(VRM->dump());
 
   // Add kill flags while we still have virtual registers.
-  LIS->addKillFlags();
+  LIS->addKillFlags(VRM);
+
+  // Live-in lists on basic blocks are required for physregs.
+  addMBBLiveIns();
 
   // Rewrite virtual registers.
   rewrite();
@@ -216,6 +224,35 @@ bool VirtRegRewriter::runOnMachineFunction(MachineFunction &fn) {
   return true;
 }
 
+// Compute MBB live-in lists from virtual register live ranges and their
+// assignments.
+void VirtRegRewriter::addMBBLiveIns() {
+  SmallVector<MachineBasicBlock*, 16> LiveIn;
+  for (unsigned Idx = 0, IdxE = MRI->getNumVirtRegs(); Idx != IdxE; ++Idx) {
+    unsigned VirtReg = TargetRegisterInfo::index2VirtReg(Idx);
+    if (MRI->reg_nodbg_empty(VirtReg))
+      continue;
+    LiveInterval &LI = LIS->getInterval(VirtReg);
+    if (LI.empty() || LIS->intervalIsInOneMBB(LI))
+      continue;
+    // This is a virtual register that is live across basic blocks. Its
+    // assigned PhysReg must be marked as live-in to those blocks.
+    unsigned PhysReg = VRM->getPhys(VirtReg);
+    assert(PhysReg != VirtRegMap::NO_PHYS_REG && "Unmapped virtual register.");
+
+    // Scan the segments of LI.
+    for (LiveInterval::const_iterator I = LI.begin(), E = LI.end(); I != E;
+         ++I) {
+      if (!Indexes->findLiveInMBBs(I->start, I->end, LiveIn))
+        continue;
+      for (unsigned i = 0, e = LiveIn.size(); i != e; ++i)
+        if (!LiveIn[i]->isLiveIn(PhysReg))
+          LiveIn[i]->addLiveIn(PhysReg);
+      LiveIn.clear();
+    }
+  }
+}
+
 void VirtRegRewriter::rewrite() {
   SmallVector<unsigned, 8> SuperDeads;
   SmallVector<unsigned, 8> SuperDefs;