1 files changed, 94 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/Mips/MipsEmitGPRestore.cpp b/contrib/llvm/lib/Target/Mips/MipsEmitGPRestore.cpp
new file mode 100644
index 0000000..f49d490
--- /dev/null
+++ b/contrib/llvm/lib/Target/Mips/MipsEmitGPRestore.cpp
@@ -0,0 +1,94 @@
+//===-- MipsEmitGPRestore.cpp - Emit GP restore instruction----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass emits instructions that restore $gp right
+// after jalr instructions.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "emit-gp-restore"
+
+#include "Mips.h"
+#include "MipsTargetMachine.h"
+#include "MipsMachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/ADT/Statistic.h"
+
+using namespace llvm;
+
+namespace {
+  struct Inserter : public MachineFunctionPass {
+
+    TargetMachine &TM;
+    const TargetInstrInfo *TII;
+
+    static char ID;
+    Inserter(TargetMachine &tm)
+      : MachineFunctionPass(ID), TM(tm), TII(tm.getInstrInfo()) { }
+
+    virtual const char *getPassName() const {
+      return "Mips Emit GP Restore";
+    }
+
+    bool runOnMachineFunction(MachineFunction &F);
+  };
+  char Inserter::ID = 0;
+} // end of anonymous namespace
+
+bool Inserter::runOnMachineFunction(MachineFunction &F) {
+  if (TM.getRelocationModel() != Reloc::PIC_)
+    return false;
+
+  bool Changed = false;
+  int FI =  F.getInfo<MipsFunctionInfo>()->getGPFI();
+
+  for (MachineFunction::iterator MFI = F.begin(), MFE = F.end();
+       MFI != MFE; ++MFI) {
+    MachineBasicBlock& MBB = *MFI;
+    MachineBasicBlock::iterator I = MFI->begin();
+
+    // If MBB is a landing pad, insert instruction that restores $gp after
+    // EH_LABEL.
+    if (MBB.isLandingPad()) {
+      // Find EH_LABEL first.
+      for (; I->getOpcode() != TargetOpcode::EH_LABEL; ++I) ;
+      
+      // Insert lw.
+      ++I;
+      DebugLoc dl = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
+      BuildMI(MBB, I, dl, TII->get(Mips::LW), Mips::GP).addImm(0)
+                                                       .addFrameIndex(FI);
+      Changed = true;
+    }
+
+    while (I != MFI->end()) {
+      if (I->getOpcode() != Mips::JALR) {
+        ++I;
+        continue;
+      }
+
+      DebugLoc dl = I->getDebugLoc();
+      // emit lw $gp, ($gp save slot on stack) after jalr
+      BuildMI(MBB, ++I, dl, TII->get(Mips::LW), Mips::GP).addImm(0)
+        .addFrameIndex(FI);
+      Changed = true;
+    }
+  } 
+
+  return Changed;
+}
+
+/// createMipsEmitGPRestorePass - Returns a pass that emits instructions that
+/// restores $gp clobbered by jalr instructions.
+FunctionPass *llvm::createMipsEmitGPRestorePass(MipsTargetMachine &tm) {
+  return new Inserter(tm);
+}
+