Skip DBG_VALUE many places in live intervals and

register coalescing.  This fixes many crashes and
places where debug info affects codegen (when
dbg.value is lowered to machine instructions, which
it isn't yet in TOT).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95739 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 17 deletions

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index c33f6b37fe..1faa5a094a 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -375,8 +375,9 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(LiveInterval &IntA,
 
   // If some of the uses of IntA.reg is already coalesced away, return false.
   // It's not possible to determine whether it's safe to perform the coalescing.
-  for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(IntA.reg),
-         UE = mri_->use_end(); UI != UE; ++UI) {
+  for (MachineRegisterInfo::use_nodbg_iterator UI = 
+         mri_->use_nodbg_begin(IntA.reg), 
+       UE = mri_->use_nodbg_end(); UI != UE; ++UI) {
     MachineInstr *UseMI = &*UI;
     SlotIndex UseIdx = li_->getInstructionIndex(UseMI);
     LiveInterval::iterator ULR = IntA.FindLiveRangeContaining(UseIdx);
@@ -430,6 +431,12 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(LiveInterval &IntA,
     ++UI;
     if (JoinedCopies.count(UseMI))
       continue;
+    if (UseMI->isDebugValue()) {
+      // FIXME These don't have an instruction index.  Not clear we have enough
+      // info to decide whether to do this replacement or not.  For now do it.
+      UseMO.setReg(NewReg);
+      continue;
+    }
     SlotIndex UseIdx = li_->getInstructionIndex(UseMI).getUseIndex();
     LiveInterval::iterator ULR = IntA.FindLiveRangeContaining(UseIdx);
     if (ULR == IntA.end() || ULR->valno != AValNo)
@@ -1029,8 +1036,9 @@ SimpleRegisterCoalescing::isWinToJoinVRWithSrcPhysReg(MachineInstr *CopyMI,
   unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
   unsigned Length = li_->getApproximateInstructionCount(DstInt);
   if (Length > Threshold &&
-      (((float)std::distance(mri_->use_begin(DstInt.reg),
-                             mri_->use_end()) / Length) < (1.0 / Threshold)))
+      (((float)std::distance(mri_->use_nodbg_begin(DstInt.reg),
+                             mri_->use_nodbg_end()) / Length) < 
+        (1.0 / Threshold)))
     return false;
 
   // If the virtual register live interval extends into a loop, turn down
@@ -1079,15 +1087,16 @@ SimpleRegisterCoalescing::isWinToJoinVRWithDstPhysReg(MachineInstr *CopyMI,
                                                      MachineBasicBlock *CopyMBB,
                                                      LiveInterval &DstInt,
                                                      LiveInterval &SrcInt) {
-  // If the virtual register live interval is long but it has low use desity,
+  // If the virtual register live interval is long but it has low use density,
   // do not join them, instead mark the physical register as its allocation
   // preference.
   const TargetRegisterClass *RC = mri_->getRegClass(SrcInt.reg);
   unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
   unsigned Length = li_->getApproximateInstructionCount(SrcInt);
   if (Length > Threshold &&
-      (((float)std::distance(mri_->use_begin(SrcInt.reg),
-                             mri_->use_end()) / Length) < (1.0 / Threshold)))
+      (((float)std::distance(mri_->use_nodbg_begin(SrcInt.reg),
+                             mri_->use_nodbg_end()) / Length) < 
+          (1.0 / Threshold)))
     return false;
 
   if (SrcInt.empty())
@@ -1140,10 +1149,10 @@ SimpleRegisterCoalescing::isWinToJoinCrossClass(unsigned LargeReg,
   unsigned LargeSize = li_->getApproximateInstructionCount(LargeInt);
   unsigned SmallSize = li_->getApproximateInstructionCount(SmallInt);
   if (SmallSize > Threshold || LargeSize > Threshold)
-    if ((float)std::distance(mri_->use_begin(SmallReg),
-                             mri_->use_end()) / SmallSize <
-        (float)std::distance(mri_->use_begin(LargeReg),
-                             mri_->use_end()) / LargeSize)
+    if ((float)std::distance(mri_->use_nodbg_begin(SmallReg),
+                             mri_->use_nodbg_end()) / SmallSize <
+        (float)std::distance(mri_->use_nodbg_begin(LargeReg),
+                             mri_->use_nodbg_end()) / LargeSize)
       return false;
   return true;
 }
@@ -1630,8 +1639,8 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
         unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
         float Ratio = 1.0 / Threshold;
         if (Length > Threshold &&
-            (((float)std::distance(mri_->use_begin(JoinVReg),
-                                   mri_->use_end()) / Length) < Ratio)) {
+            (((float)std::distance(mri_->use_nodbg_begin(JoinVReg),
+                                   mri_->use_nodbg_end()) / Length) < Ratio)) {
           mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
           ++numAborts;
           DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
@@ -2564,8 +2573,8 @@ SimpleRegisterCoalescing::differingRegisterClasses(unsigned RegA,
   return !RegClassA->contains(RegB);
 }
 
-/// lastRegisterUse - Returns the last use of the specific register between
-/// cycles Start and End or NULL if there are no uses.
+/// lastRegisterUse - Returns the last (non-debug) use of the specific register
+/// between cycles Start and End or NULL if there are no uses.
 MachineOperand *
 SimpleRegisterCoalescing::lastRegisterUse(SlotIndex Start,
                                           SlotIndex End,
@@ -2574,8 +2583,8 @@ SimpleRegisterCoalescing::lastRegisterUse(SlotIndex Start,
   UseIdx = SlotIndex();
   if (TargetRegisterInfo::isVirtualRegister(Reg)) {
     MachineOperand *LastUse = NULL;
-    for (MachineRegisterInfo::use_iterator I = mri_->use_begin(Reg),
-           E = mri_->use_end(); I != E; ++I) {
+    for (MachineRegisterInfo::use_nodbg_iterator I = mri_->use_nodbg_begin(Reg),
+           E = mri_->use_nodbg_end(); I != E; ++I) {
       MachineOperand &Use = I.getOperand();
       MachineInstr *UseMI = Use.getParent();
       unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;