1 files changed, 22 insertions, 24 deletions

diff --git a/lib/Target/NVPTX/NVPTXFrameLowering.cpp b/lib/Target/NVPTX/NVPTXFrameLowering.cpp
index 5503494..9b34aef 100644
--- a/lib/Target/NVPTX/NVPTXFrameLowering.cpp
+++ b/lib/Target/NVPTX/NVPTXFrameLowering.cpp
@@ -35,35 +35,33 @@ void NVPTXFrameLowering::emitPrologue(MachineFunction &MF,
                                       MachineBasicBlock &MBB) const {
   if (MF.getFrameInfo()->hasStackObjects()) {
     assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
-    // Insert "mov.u32 %SP, %Depot"
-    MachineBasicBlock::iterator MBBI = MBB.begin();
+    MachineInstr *MI = MBB.begin();
+    MachineRegisterInfo &MR = MF.getRegInfo();
+
     // This instruction really occurs before first instruction
     // in the BB, so giving it no debug location.
     DebugLoc dl = DebugLoc();
 
-    MachineRegisterInfo &MRI = MF.getRegInfo();
-
-    // mov %SPL, %depot;
-    // cvta.local %SP, %SPL;
-    if (static_cast<const NVPTXTargetMachine &>(MF.getTarget()).is64Bit()) {
-      unsigned LocalReg = MRI.createVirtualRegister(&NVPTX::Int64RegsRegClass);
-      MachineInstr *MI =
-          BuildMI(MBB, MBBI, dl, MF.getSubtarget().getInstrInfo()->get(
-                                     NVPTX::cvta_local_yes_64),
-                  NVPTX::VRFrame).addReg(LocalReg);
-      BuildMI(MBB, MI, dl,
-              MF.getSubtarget().getInstrInfo()->get(NVPTX::MOV_DEPOT_ADDR_64),
-              LocalReg).addImm(MF.getFunctionNumber());
-    } else {
-      unsigned LocalReg = MRI.createVirtualRegister(&NVPTX::Int32RegsRegClass);
-      MachineInstr *MI =
-          BuildMI(MBB, MBBI, dl,
-                  MF.getSubtarget().getInstrInfo()->get(NVPTX::cvta_local_yes),
-                  NVPTX::VRFrame).addReg(LocalReg);
-      BuildMI(MBB, MI, dl,
-              MF.getSubtarget().getInstrInfo()->get(NVPTX::MOV_DEPOT_ADDR),
-              LocalReg).addImm(MF.getFunctionNumber());
+    // Emits
+    //   mov %SPL, %depot;
+    //   cvta.local %SP, %SPL;
+    // for local address accesses in MF.
+    bool Is64Bit =
+        static_cast<const NVPTXTargetMachine &>(MF.getTarget()).is64Bit();
+    unsigned CvtaLocalOpcode =
+        (Is64Bit ? NVPTX::cvta_local_yes_64 : NVPTX::cvta_local_yes);
+    unsigned MovDepotOpcode =
+        (Is64Bit ? NVPTX::MOV_DEPOT_ADDR_64 : NVPTX::MOV_DEPOT_ADDR);
+    if (!MR.use_empty(NVPTX::VRFrame)) {
+      // If %SP is not used, do not bother emitting "cvta.local %SP, %SPL".
+      MI = BuildMI(MBB, MI, dl,
+                   MF.getSubtarget().getInstrInfo()->get(CvtaLocalOpcode),
+                   NVPTX::VRFrame)
+               .addReg(NVPTX::VRFrameLocal);
     }
+    BuildMI(MBB, MI, dl, MF.getSubtarget().getInstrInfo()->get(MovDepotOpcode),
+            NVPTX::VRFrameLocal)
+        .addImm(MF.getFunctionNumber());
   }
 }