--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/Target/NVPTX/NVPTXReplaceImageHandles.cpp	Mon Sep 08 22:06:00 2014 +0900
@@ -0,0 +1,189 @@
+//===-- NVPTXReplaceImageHandles.cpp - Replace image handles for Fermi ----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source 
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// On Fermi, image handles are not supported. To work around this, we traverse
+// the machine code and replace image handles with concrete symbols. For this
+// to work reliably, inlining of all function call must be performed.
+//
+//===----------------------------------------------------------------------===//
+
+#include "NVPTX.h"
+#include "NVPTXMachineFunctionInfo.h"
+#include "NVPTXSubtarget.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/ADT/DenseSet.h"
+
+using namespace llvm;
+
+namespace {
+class NVPTXReplaceImageHandles : public MachineFunctionPass {
+private:
+  static char ID;
+  DenseSet<MachineInstr *> InstrsToRemove;
+
+public:
+  NVPTXReplaceImageHandles();
+
+  bool runOnMachineFunction(MachineFunction &MF) override;
+
+  const char *getPassName() const override {
+    return "NVPTX Replace Image Handles";
+  }
+private:
+  bool processInstr(MachineInstr &MI);
+  void replaceImageHandle(MachineOperand &Op, MachineFunction &MF);
+  bool findIndexForHandle(MachineOperand &Op, MachineFunction &MF,
+                          unsigned &Idx);
+};
+}
+
+char NVPTXReplaceImageHandles::ID = 0;
+
+NVPTXReplaceImageHandles::NVPTXReplaceImageHandles()
+  : MachineFunctionPass(ID) {}
+
+bool NVPTXReplaceImageHandles::runOnMachineFunction(MachineFunction &MF) {
+  bool Changed = false;
+  InstrsToRemove.clear();
+
+  for (MachineFunction::iterator BI = MF.begin(), BE = MF.end(); BI != BE;
+       ++BI) {
+    for (MachineBasicBlock::iterator I = (*BI).begin(), E = (*BI).end();
+         I != E; ++I) {
+      MachineInstr &MI = *I;
+      Changed |= processInstr(MI);
+    }
+  }
+
+  // Now clean up any handle-access instructions
+  // This is needed in debug mode when code cleanup passes are not executed,
+  // but we need the handle access to be eliminated because they are not
+  // valid instructions when image handles are disabled.
+  for (DenseSet<MachineInstr *>::iterator I = InstrsToRemove.begin(),
+       E = InstrsToRemove.end(); I != E; ++I) {
+    (*I)->eraseFromParent();
+  }
+  return Changed;
+}
+
+bool NVPTXReplaceImageHandles::processInstr(MachineInstr &MI) {
+  MachineFunction &MF = *MI.getParent()->getParent();
+  const MCInstrDesc &MCID = MI.getDesc();
+
+  if (MCID.TSFlags & NVPTXII::IsTexFlag) {
+    // This is a texture fetch, so operand 4 is a texref and operand 5 is
+    // a samplerref
+    MachineOperand &TexHandle = MI.getOperand(4);
+    replaceImageHandle(TexHandle, MF);
+
+    if (!(MCID.TSFlags & NVPTXII::IsTexModeUnifiedFlag)) {
+      MachineOperand &SampHandle = MI.getOperand(5);
+      replaceImageHandle(SampHandle, MF);
+    }
+
+    return true;
+  } else if (MCID.TSFlags & NVPTXII::IsSuldMask) {
+    unsigned VecSize =
+      1 << (((MCID.TSFlags & NVPTXII::IsSuldMask) >> NVPTXII::IsSuldShift) - 1);
+
+    // For a surface load of vector size N, the Nth operand will be the surfref
+    MachineOperand &SurfHandle = MI.getOperand(VecSize);
+
+    replaceImageHandle(SurfHandle, MF);
+
+    return true;
+  } else if (MCID.TSFlags & NVPTXII::IsSustFlag) {
+    // This is a surface store, so operand 0 is a surfref
+    MachineOperand &SurfHandle = MI.getOperand(0);
+
+    replaceImageHandle(SurfHandle, MF);
+
+    return true;
+  } else if (MCID.TSFlags & NVPTXII::IsSurfTexQueryFlag) {
+    // This is a query, so operand 1 is a surfref/texref
+    MachineOperand &Handle = MI.getOperand(1);
+
+    replaceImageHandle(Handle, MF);
+
+    return true; 
+  }
+
+  return false;
+}
+
+void NVPTXReplaceImageHandles::
+replaceImageHandle(MachineOperand &Op, MachineFunction &MF) {
+  unsigned Idx;
+  if (findIndexForHandle(Op, MF, Idx)) {
+    Op.ChangeToImmediate(Idx);
+  }
+}
+
+bool NVPTXReplaceImageHandles::
+findIndexForHandle(MachineOperand &Op, MachineFunction &MF, unsigned &Idx) {
+  const MachineRegisterInfo &MRI = MF.getRegInfo();
+  NVPTXMachineFunctionInfo *MFI = MF.getInfo<NVPTXMachineFunctionInfo>();
+
+  assert(Op.isReg() && "Handle is not in a reg?");
+
+  // Which instruction defines the handle?
+  MachineInstr &TexHandleDef = *MRI.getVRegDef(Op.getReg());
+
+  switch (TexHandleDef.getOpcode()) {
+  case NVPTX::LD_i64_avar: {
+    // The handle is a parameter value being loaded, replace with the
+    // parameter symbol
+    const NVPTXSubtarget &ST = MF.getTarget().getSubtarget<NVPTXSubtarget>();
+    if (ST.getDrvInterface() == NVPTX::CUDA) {
+      // For CUDA, we preserve the param loads coming from function arguments
+      return false;
+    }
+
+    assert(TexHandleDef.getOperand(6).isSymbol() && "Load is not a symbol!");
+    StringRef Sym = TexHandleDef.getOperand(6).getSymbolName();
+    std::string ParamBaseName = MF.getName();
+    ParamBaseName += "_param_";
+    assert(Sym.startswith(ParamBaseName) && "Invalid symbol reference");
+    unsigned Param = atoi(Sym.data()+ParamBaseName.size());
+    std::string NewSym;
+    raw_string_ostream NewSymStr(NewSym);
+    NewSymStr << MF.getFunction()->getName() << "_param_" << Param;
+
+    InstrsToRemove.insert(&TexHandleDef);
+    Idx = MFI->getImageHandleSymbolIndex(NewSymStr.str().c_str());
+    return true;
+  }
+  case NVPTX::texsurf_handles: {
+    // The handle is a global variable, replace with the global variable name
+    assert(TexHandleDef.getOperand(1).isGlobal() && "Load is not a global!");
+    const GlobalValue *GV = TexHandleDef.getOperand(1).getGlobal();
+    assert(GV->hasName() && "Global sampler must be named!");
+    InstrsToRemove.insert(&TexHandleDef);
+    Idx = MFI->getImageHandleSymbolIndex(GV->getName().data());
+    return true;
+  }
+  case NVPTX::nvvm_move_i64:
+  case TargetOpcode::COPY: {
+    bool Res = findIndexForHandle(TexHandleDef.getOperand(1), MF, Idx);
+    if (Res) {
+      InstrsToRemove.insert(&TexHandleDef);
+    }
+    return Res;
+  }
+  default:
+    llvm_unreachable("Unknown instruction operating on handle");
+  }
+}
+
+MachineFunctionPass *llvm::createNVPTXReplaceImageHandlesPass() {
+  return new NVPTXReplaceImageHandles();
+}