1 files changed, 132 insertions, 0 deletions
diff --git a/llvm/lib/Target/Sparc/FPMover.cpp b/llvm/lib/Target/Sparc/FPMover.cpp
new file mode 100644
index 00000000000..70f203ccca9
--- /dev/null
+++ b/llvm/lib/Target/Sparc/FPMover.cpp
@@ -0,0 +1,132 @@
+//===-- FPMover.cpp - Sparc double-precision floating point move fixer ----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Expand FpMOVD/FpABSD/FpNEGD instructions into their single-precision pieces.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Sparc.h"
+#include "SparcSubtarget.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Support/Debug.h"
+#include <iostream>
+using namespace llvm;
+
+namespace {
+  Statistic<> NumFpDs("fpmover", "Number of instructions translated");
+  Statistic<> NoopFpDs("fpmover", "Number of noop instructions removed");
+
+  struct FPMover : public MachineFunctionPass {
+    /// Target machine description which we query for reg. names, data
+    /// layout, etc.
+    ///
+    TargetMachine &TM;
+
+    FPMover(TargetMachine &tm) : TM(tm) { }
+
+    virtual const char *getPassName() const {
+      return "Sparc Double-FP Move Fixer";
+    }
+
+    bool runOnMachineBasicBlock(MachineBasicBlock &MBB);
+    bool runOnMachineFunction(MachineFunction &F);
+  };
+} // end of anonymous namespace
+
+/// createSparcFPMoverPass - Returns a pass that turns FpMOVD
+/// instructions into FMOVS instructions
+///
+FunctionPass *llvm::createSparcFPMoverPass(TargetMachine &tm) {
+  return new FPMover(tm);
+}
+
+/// getDoubleRegPair - Given a DFP register, return the even and odd FP
+/// registers that correspond to it.
+static void getDoubleRegPair(unsigned DoubleReg, unsigned &EvenReg,
+                             unsigned &OddReg) {
+  static const unsigned EvenHalvesOfPairs[] = {
+    SP::F0, SP::F2, SP::F4, SP::F6, SP::F8, SP::F10, SP::F12, SP::F14,
+    SP::F16, SP::F18, SP::F20, SP::F22, SP::F24, SP::F26, SP::F28, SP::F30
+  };
+  static const unsigned OddHalvesOfPairs[] = {
+    SP::F1, SP::F3, SP::F5, SP::F7, SP::F9, SP::F11, SP::F13, SP::F15,
+    SP::F17, SP::F19, SP::F21, SP::F23, SP::F25, SP::F27, SP::F29, SP::F31
+  };
+  static const unsigned DoubleRegsInOrder[] = {
+    SP::D0, SP::D1, SP::D2, SP::D3, SP::D4, SP::D5, SP::D6, SP::D7, SP::D8,
+    SP::D9, SP::D10, SP::D11, SP::D12, SP::D13, SP::D14, SP::D15
+  };
+  for (unsigned i = 0; i < sizeof(DoubleRegsInOrder)/sizeof(unsigned); ++i)
+    if (DoubleRegsInOrder[i] == DoubleReg) {
+      EvenReg = EvenHalvesOfPairs[i];
+      OddReg = OddHalvesOfPairs[i];
+      return;
+    }
+  assert(0 && "Can't find reg");
+}
+
+/// runOnMachineBasicBlock - Fixup FpMOVD instructions in this MBB.
+///
+bool FPMover::runOnMachineBasicBlock(MachineBasicBlock &MBB) {
+  bool Changed = false;
+  for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end(); ) {
+    MachineInstr *MI = I++;
+    if (MI->getOpcode() == SP::FpMOVD || MI->getOpcode() == SP::FpABSD ||
+        MI->getOpcode() == SP::FpNEGD) {
+      Changed = true;
+      unsigned DestDReg = MI->getOperand(0).getReg();
+      unsigned SrcDReg  = MI->getOperand(1).getReg();
+      if (DestDReg == SrcDReg && MI->getOpcode() == SP::FpMOVD) {
+        MBB.erase(MI);   // Eliminate the noop copy.
+        ++NoopFpDs;
+        continue;
+      }
+      
+      unsigned EvenSrcReg = 0, OddSrcReg = 0, EvenDestReg = 0, OddDestReg = 0;
+      getDoubleRegPair(DestDReg, EvenDestReg, OddDestReg);
+      getDoubleRegPair(SrcDReg, EvenSrcReg, OddSrcReg);
+
+      if (MI->getOpcode() == SP::FpMOVD)
+        MI->setOpcode(SP::FMOVS);
+      else if (MI->getOpcode() == SP::FpNEGD)
+        MI->setOpcode(SP::FNEGS);
+      else if (MI->getOpcode() == SP::FpABSD)
+        MI->setOpcode(SP::FABSS);
+      else
+        assert(0 && "Unknown opcode!");
+        
+      MI->SetMachineOperandReg(0, EvenDestReg);
+      MI->SetMachineOperandReg(1, EvenSrcReg);
+      DEBUG(std::cerr << "FPMover: the modified instr is: " << *MI);
+      // Insert copy for the other half of the double.
+      if (DestDReg != SrcDReg) {
+        MI = BuildMI(MBB, I, SP::FMOVS, 1, OddDestReg).addReg(OddSrcReg);
+        DEBUG(std::cerr << "FPMover: the inserted instr is: " << *MI);
+      }
+      ++NumFpDs;
+    }
+  }
+  return Changed;
+}
+
+bool FPMover::runOnMachineFunction(MachineFunction &F) {
+  // If the target has V9 instructions, the fp-mover pseudos will never be
+  // emitted.  Avoid a scan of the instructions to improve compile time.
+  if (TM.getSubtarget<SparcSubtarget>().isV9())
+    return false;
+  
+  bool Changed = false;
+  for (MachineFunction::iterator FI = F.begin(), FE = F.end();
+       FI != FE; ++FI)
+    Changed |= runOnMachineBasicBlock(*FI);
+  return Changed;
+}