X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTarget%2FSparc%2FSparcRegisterInfo.cpp;h=fe91a3d070291944fde3eabc1eb28cddfcf7f0fa;hb=6a2e7ac0b6647a409394e58b385e579ea62b5cba;hp=3af4c614cd445da87c6c3d70ed20822bedb86b25;hpb=2b9355f2d9888d6a011353610b9ca24818de59a2;p=oota-llvm.git

diff --git a/lib/Target/Sparc/SparcRegisterInfo.cpp b/lib/Target/Sparc/SparcRegisterInfo.cpp
index 3af4c614cd4..fe91a3d0702 100644
--- a/lib/Target/Sparc/SparcRegisterInfo.cpp
+++ b/lib/Target/Sparc/SparcRegisterInfo.cpp
@@ -13,6 +13,7 @@
 
 #include "SparcRegisterInfo.h"
 #include "Sparc.h"
+#include "SparcMachineFunctionInfo.h"
 #include "SparcSubtarget.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/STLExtras.h"
@@ -20,6 +21,7 @@
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/IR/Type.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Target/TargetInstrInfo.h"
 
@@ -28,6 +30,10 @@
 
 using namespace llvm;
 
+static cl::opt<bool>
+ReserveAppRegisters("sparc-reserve-app-registers", cl::Hidden, cl::init(false),
+                    cl::desc("Reserve application registers (%g2-%g4)"));
+
 SparcRegisterInfo::SparcRegisterInfo(SparcSubtarget &st,
                                      const TargetInstrInfo &tii)
   : SparcGenRegisterInfo(SP::I7), Subtarget(st), TII(tii) {
@@ -43,14 +49,21 @@ BitVector SparcRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
   BitVector Reserved(getNumRegs());
   // FIXME: G1 reserved for now for large imm generation by frame code.
   Reserved.set(SP::G1);
-  Reserved.set(SP::G2);
-  Reserved.set(SP::G3);
-  Reserved.set(SP::G4);
+
+  // G1-G4 can be used in applications.
+  if (ReserveAppRegisters) {
+    Reserved.set(SP::G2);
+    Reserved.set(SP::G3);
+    Reserved.set(SP::G4);
+  }
+  // G5 is not reserved in 64 bit mode.
+  if (!Subtarget.is64Bit())
+    Reserved.set(SP::G5);
+
   Reserved.set(SP::O6);
   Reserved.set(SP::I6);
   Reserved.set(SP::I7);
   Reserved.set(SP::G0);
-  Reserved.set(SP::G5);
   Reserved.set(SP::G6);
   Reserved.set(SP::G7);
   return Reserved;
@@ -77,21 +90,29 @@ SparcRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   int64_t Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
                    MI.getOperand(FIOperandNum + 1).getImm() +
                    Subtarget.getStackPointerBias();
+  SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
+  unsigned FramePtr = SP::I6;
+  if (FuncInfo->isLeafProc()) {
+    // Use %sp and adjust offset if needed.
+    FramePtr = SP::O6;
+    int stackSize = MF.getFrameInfo()->getStackSize();
+    Offset += (stackSize) ? Subtarget.getAdjustedFrameSize(stackSize) : 0 ;
+  }
 
   // Replace frame index with a frame pointer reference.
   if (Offset >= -4096 && Offset <= 4095) {
     // If the offset is small enough to fit in the immediate field, directly
     // encode it.
-    MI.getOperand(FIOperandNum).ChangeToRegister(SP::I6, false);
+    MI.getOperand(FIOperandNum).ChangeToRegister(FramePtr, false);
     MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
   } else {
-    // Otherwise, emit a G1 = SETHI %hi(offset).  FIXME: it would be better to 
+    // Otherwise, emit a G1 = SETHI %hi(offset).  FIXME: it would be better to
     // scavenge a register here instead of reserving G1 all of the time.
     unsigned OffHi = (unsigned)Offset >> 10U;
     BuildMI(*MI.getParent(), II, dl, TII.get(SP::SETHIi), SP::G1).addImm(OffHi);
     // Emit G1 = G1 + I6
     BuildMI(*MI.getParent(), II, dl, TII.get(SP::ADDrr), SP::G1).addReg(SP::G1)
-      .addReg(SP::I6);
+      .addReg(FramePtr);
     // Insert: G1+%lo(offset) into the user.
     MI.getOperand(FIOperandNum).ChangeToRegister(SP::G1, false);
     MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset & ((1 << 10)-1));