Fix SingleSource/Regression/C/2005-05-06-LongLongSignedShift.c, we were not

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

diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index 825b56d784afdabf8ee3ba557cfe780a665250cc..803161026012bf22c3d740791109f0ec7a5f5484 100644 (file)
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -33,6 +33,7 @@
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/Config/alloca.h"
 using namespace llvm;
 
 static RegisterAnalysis<LiveVariables> X("livevars", "Live Variable Analysis");
@@ -155,11 +156,10 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &MF) {
   // physical register.  This is a purely local property, because all physical
   // register references as presumed dead across basic blocks.
   //
-  MachineInstr *PhysRegInfoA[RegInfo->getNumRegs()];
-  bool          PhysRegUsedA[RegInfo->getNumRegs()];
-  std::fill(PhysRegInfoA, PhysRegInfoA+RegInfo->getNumRegs(), (MachineInstr*)0);
-  PhysRegInfo = PhysRegInfoA;
-  PhysRegUsed = PhysRegUsedA;
+  PhysRegInfo = (MachineInstr**)alloca(sizeof(MachineInstr*) * 
+                                       RegInfo->getNumRegs());
+  PhysRegUsed = (bool*)alloca(sizeof(bool)*RegInfo->getNumRegs());
+  std::fill(PhysRegInfo, PhysRegInfo+RegInfo->getNumRegs(), (MachineInstr*)0);
 
   /// Get some space for a respectable number of registers...
   VirtRegInfo.resize(64);
@@ -302,12 +302,20 @@ void LiveVariables::instructionChanged(MachineInstr *OldMI,
   // the instruction.
   for (unsigned i = 0, e = OldMI->getNumOperands(); i != e; ++i) {
     MachineOperand &MO = OldMI->getOperand(i);
-    if (MO.isRegister() && MO.isDef() && MO.getReg() &&
+    if (MO.isRegister() && MO.getReg() &&
         MRegisterInfo::isVirtualRegister(MO.getReg())) {
       unsigned Reg = MO.getReg();
       VarInfo &VI = getVarInfo(Reg);
-      if (VI.DefInst == OldMI)
-        VI.DefInst = NewMI;
+      if (MO.isDef()) {
+        // Update the defining instruction.
+        if (VI.DefInst == OldMI)
+          VI.DefInst = NewMI;
+      }
+      if (MO.isUse()) {
+        // If this is a kill of the value, update the VI kills list.
+        if (VI.removeKill(OldMI))
+          VI.Kills.push_back(NewMI);   // Yes, there was a kill of it
+      }
     }
   }