DAGCombiner: Use isNullConstant() where possible

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

diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index 755faf631aff2a059b4c6184f4cc746077a08812..559ff3ec09c40160e1ebe5b8ec5eae7c569ca317 100644 (file)
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -20,6 +20,7 @@
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
@@ -27,7 +28,6 @@
 #include "llvm/CodeGen/RegisterPressure.h"
 #include "llvm/CodeGen/ScheduleDFS.h"
 #include "llvm/IR/Operator.h"
-#include "llvm/MC/MCInstrItineraries.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Format.h"
@@ -143,6 +143,13 @@ static void getUnderlyingObjectsForInstr(const MachineInstr *MI,
 
   if (const PseudoSourceValue *PSV =
       (*MI->memoperands_begin())->getPseudoValue()) {
+    // Function that contain tail calls don't have unique PseudoSourceValue
+    // objects. Two PseudoSourceValues might refer to the same or overlapping
+    // locations. The client code calling this function assumes this is not the
+    // case. So return a conservative answer of no known object.
+    if (MFI->hasTailCall())
+      return;
+
     // For now, ignore PseudoSourceValues which may alias LLVM IR values
     // because the code that uses this function has no way to cope with
     // such aliases.
@@ -1107,6 +1114,12 @@ static void toggleBundleKillFlag(MachineInstr *MI, unsigned Reg,
       if (!MO->isReg() || MO->isDef() || Reg != MO->getReg())
         continue;
 
+      // DEBUG_VALUE nodes do not contribute to code generation and should
+      // always be ignored.  Failure to do so may result in trying to modify
+      // KILL flags on DEBUG_VALUE nodes, which is distressing.
+      if (MO->isDebug())
+        continue;
+
       // If the register has the internal flag then it could be killing an
       // internal def of the register.  In this case, just skip.  We only want
       // to toggle the flag on operands visible outside the bundle.