1 files changed, 176 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/PPCVSXCopy.cpp b/lib/Target/PowerPC/PPCVSXCopy.cpp
new file mode 100644
index 0000000..5e3ae2a
--- /dev/null
+++ b/lib/Target/PowerPC/PPCVSXCopy.cpp
@@ -0,0 +1,176 @@
+//===-------------- PPCVSXCopy.cpp - VSX Copy Legalization ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// A pass which deals with the complexity of generating legal VSX register
+// copies to/from register classes which partially overlap with the VSX
+// register file.
+//
+//===----------------------------------------------------------------------===//
+
+#include "PPCInstrInfo.h"
+#include "MCTargetDesc/PPCPredicates.h"
+#include "PPC.h"
+#include "PPCHazardRecognizers.h"
+#include "PPCInstrBuilder.h"
+#include "PPCMachineFunctionInfo.h"
+#include "PPCTargetMachine.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "ppc-vsx-copy"
+
+namespace llvm {
+  void initializePPCVSXCopyPass(PassRegistry&);
+}
+
+namespace {
+  // PPCVSXCopy pass - For copies between VSX registers and non-VSX registers
+  // (Altivec and scalar floating-point registers), we need to transform the
+  // copies into subregister copies with other restrictions.
+  struct PPCVSXCopy : public MachineFunctionPass {
+    static char ID;
+    PPCVSXCopy() : MachineFunctionPass(ID) {
+      initializePPCVSXCopyPass(*PassRegistry::getPassRegistry());
+    }
+
+    const TargetInstrInfo *TII;
+
+    bool IsRegInClass(unsigned Reg, const TargetRegisterClass *RC,
+                      MachineRegisterInfo &MRI) {
+      if (TargetRegisterInfo::isVirtualRegister(Reg)) {
+        return RC->hasSubClassEq(MRI.getRegClass(Reg));
+      } else if (RC->contains(Reg)) {
+        return true;
+      }
+
+      return false;
+    }
+
+    bool IsVSReg(unsigned Reg, MachineRegisterInfo &MRI) {
+      return IsRegInClass(Reg, &PPC::VSRCRegClass, MRI);
+    }
+
+    bool IsVRReg(unsigned Reg, MachineRegisterInfo &MRI) {
+      return IsRegInClass(Reg, &PPC::VRRCRegClass, MRI);
+    }
+
+    bool IsF8Reg(unsigned Reg, MachineRegisterInfo &MRI) {
+      return IsRegInClass(Reg, &PPC::F8RCRegClass, MRI);
+    }
+
+protected:
+    bool processBlock(MachineBasicBlock &MBB) {
+      bool Changed = false;
+
+      MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
+      for (MachineBasicBlock::iterator I = MBB.begin(), IE = MBB.end();
+           I != IE; ++I) {
+        MachineInstr *MI = I;
+        if (!MI->isFullCopy())
+          continue;
+
+        MachineOperand &DstMO = MI->getOperand(0);
+        MachineOperand &SrcMO = MI->getOperand(1);
+
+        if ( IsVSReg(DstMO.getReg(), MRI) &&
+            !IsVSReg(SrcMO.getReg(), MRI)) {
+          // This is a copy *to* a VSX register from a non-VSX register.
+          Changed = true;
+
+          const TargetRegisterClass *SrcRC =
+            IsVRReg(SrcMO.getReg(), MRI) ? &PPC::VSHRCRegClass :
+                                           &PPC::VSLRCRegClass;
+          assert((IsF8Reg(SrcMO.getReg(), MRI) ||
+                  IsVRReg(SrcMO.getReg(), MRI)) &&
+                 "Unknown source for a VSX copy");
+
+          unsigned NewVReg = MRI.createVirtualRegister(SrcRC);
+          BuildMI(MBB, MI, MI->getDebugLoc(),
+                  TII->get(TargetOpcode::SUBREG_TO_REG), NewVReg)
+            .addImm(1) // add 1, not 0, because there is no implicit clearing
+                       // of the high bits.
+            .addOperand(SrcMO)
+            .addImm(IsVRReg(SrcMO.getReg(), MRI) ? PPC::sub_128 :
+                                                   PPC::sub_64);
+
+          // The source of the original copy is now the new virtual register.
+          SrcMO.setReg(NewVReg);
+        } else if (!IsVSReg(DstMO.getReg(), MRI) &&
+                    IsVSReg(SrcMO.getReg(), MRI)) {
+          // This is a copy *from* a VSX register to a non-VSX register.
+          Changed = true;
+
+          const TargetRegisterClass *DstRC =
+            IsVRReg(DstMO.getReg(), MRI) ? &PPC::VSHRCRegClass :
+                                           &PPC::VSLRCRegClass;
+          assert((IsF8Reg(DstMO.getReg(), MRI) ||
+                  IsVRReg(DstMO.getReg(), MRI)) &&
+                 "Unknown destination for a VSX copy");
+
+          // Copy the VSX value into a new VSX register of the correct subclass.
+          unsigned NewVReg = MRI.createVirtualRegister(DstRC);
+          BuildMI(MBB, MI, MI->getDebugLoc(),
+                  TII->get(TargetOpcode::COPY), NewVReg)
+            .addOperand(SrcMO);
+
+          // Transform the original copy into a subregister extraction copy.
+          SrcMO.setReg(NewVReg);
+          SrcMO.setSubReg(IsVRReg(DstMO.getReg(), MRI) ? PPC::sub_128 :
+                                                         PPC::sub_64);
+        }
+      }
+
+      return Changed;
+    }
+
+public:
+    bool runOnMachineFunction(MachineFunction &MF) override {
+      // If we don't have VSX on the subtarget, don't do anything.
+      const PPCSubtarget &STI = MF.getSubtarget<PPCSubtarget>();
+      if (!STI.hasVSX())
+        return false;
+      TII = STI.getInstrInfo();
+
+      bool Changed = false;
+
+      for (MachineFunction::iterator I = MF.begin(); I != MF.end();) {
+        MachineBasicBlock &B = *I++;
+        if (processBlock(B))
+          Changed = true;
+      }
+
+      return Changed;
+    }
+
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
+      MachineFunctionPass::getAnalysisUsage(AU);
+    }
+  };
+}
+
+INITIALIZE_PASS(PPCVSXCopy, DEBUG_TYPE,
+                "PowerPC VSX Copy Legalization", false, false)
+
+char PPCVSXCopy::ID = 0;
+FunctionPass*
+llvm::createPPCVSXCopyPass() { return new PPCVSXCopy(); }
+