[llvm-commits] CVS: llvm/lib/CodeGen/BranchFolding.cpp RegisterScavenging.cpp

[Dale Johannesen]

Changes in directory llvm/lib/CodeGen:

BranchFolding.cpp updated: 1.44 -> 1.45
RegisterScavenging.cpp updated: 1.12 -> 1.13
---
Log message:

maintain LiveIn when splitting blocks (register scavenging needs it)


---
Diffs of the changes:  (+29 -1)

 BranchFolding.cpp      |   23 ++++++++++++++++++++++-
 RegisterScavenging.cpp |    7 +++++++
 2 files changed, 29 insertions(+), 1 deletion(-)


Index: llvm/lib/CodeGen/BranchFolding.cpp
diff -u llvm/lib/CodeGen/BranchFolding.cpp:1.44 llvm/lib/CodeGen/BranchFolding.cpp:1.45
--- llvm/lib/CodeGen/BranchFolding.cpp:1.44	Thu Feb 22 10:39:03 2007
+++ llvm/lib/CodeGen/BranchFolding.cpp	Tue Mar 20 16:35:06 2007
@@ -21,8 +21,10 @@
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/MRegisterInfo.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/ADT/Statistic.h"
@@ -49,7 +51,9 @@
                                  MachineBasicBlock *NewDest);
     MachineBasicBlock *SplitMBBAt(MachineBasicBlock &CurMBB,
                                   MachineBasicBlock::iterator BBI1);
-        
+
+    const MRegisterInfo *RegInfo;
+    RegScavenger *RS;
     // Branch optzn.
     bool OptimizeBranches(MachineFunction &MF);
     void OptimizeBlock(MachineBasicBlock *MBB);
@@ -95,6 +99,9 @@
   TII = MF.getTarget().getInstrInfo();
   if (!TII) return false;
 
+  RegInfo = MF.getTarget().getRegisterInfo();
+  RS = RegInfo->requiresRegisterScavenging(MF) ? new RegScavenger() : NULL;
+
   MMI = getAnalysisToUpdate<MachineModuleInfo>();
   
   bool EverMadeChange = false;
@@ -153,6 +160,7 @@
       }
   }
   
+  delete RS;
   return EverMadeChange;
 }
 
@@ -280,6 +288,19 @@
   
   // Splice the code over.
   NewMBB->splice(NewMBB->end(), &CurMBB, BBI1, CurMBB.end());
+
+  // For targets that use the register scavenger, we must maintain LiveIns.
+  if (RS) {
+    RS->enterBasicBlock(&CurMBB);
+    if (!CurMBB.empty())
+      RS->forward(prior(CurMBB.end()));
+    BitVector RegsLiveAtExit(RegInfo->getNumRegs());
+    RS->getRegsUsed(RegsLiveAtExit, false);
+    for (unsigned int i=0, e=RegInfo->getNumRegs(); i!=e; i++)
+      if (RegsLiveAtExit[i])
+        NewMBB->addLiveIn(i);
+  }
+
   return NewMBB;
 }
 


Index: llvm/lib/CodeGen/RegisterScavenging.cpp
diff -u llvm/lib/CodeGen/RegisterScavenging.cpp:1.12 llvm/lib/CodeGen/RegisterScavenging.cpp:1.13
--- llvm/lib/CodeGen/RegisterScavenging.cpp:1.12	Tue Mar  6 15:58:15 2007
+++ llvm/lib/CodeGen/RegisterScavenging.cpp	Tue Mar 20 16:35:06 2007
@@ -180,6 +180,13 @@
   setUsed(ChangedRegs);
 }
 
+void RegScavenger::getRegsUsed(BitVector &used, bool includeReserved) {
+  if (includeReserved)
+    used = RegStates;
+  else
+    used = RegStates & ~ReservedRegs;
+}
+
 /// CreateRegClassMask - Set the bits that represent the registers in the
 /// TargetRegisterClass.
 static void CreateRegClassMask(const TargetRegisterClass *RC, BitVector &Mask) {