Reapply [FastISel] Let the target decide first if it wants to materialize a constant...

[oota-llvm.git] / lib / Target / MSP430 / MSP430FrameLowering.cpp

diff --git a/lib/Target/MSP430/MSP430FrameLowering.cpp b/lib/Target/MSP430/MSP430FrameLowering.cpp
index a312c8d5b2589beeb1fe480c22bf12b01de6baf3..2902acf2088cda21342055251b6da802728b3ba6 100644 (file)
--- a/lib/Target/MSP430/MSP430FrameLowering.cpp
+++ b/lib/Target/MSP430/MSP430FrameLowering.cpp
@@ -14,15 +14,16 @@
 #include "MSP430FrameLowering.h"
 #include "MSP430InstrInfo.h"
 #include "MSP430MachineFunctionInfo.h"
-#include "llvm/Function.h"
+#include "MSP430Subtarget.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/DataLayout.h"
-#include "llvm/Target/TargetOptions.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Function.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetOptions.h"
 
 using namespace llvm;
 
@@ -43,7 +44,7 @@ void MSP430FrameLowering::emitPrologue(MachineFunction &MF) const {
   MachineFrameInfo *MFI = MF.getFrameInfo();
   MSP430MachineFunctionInfo *MSP430FI = MF.getInfo<MSP430MachineFunctionInfo>();
   const MSP430InstrInfo &TII =
-    *static_cast<const MSP430InstrInfo*>(MF.getTarget().getInstrInfo());
+      *static_cast<const MSP430InstrInfo *>(MF.getSubtarget().getInstrInfo());
 
   MachineBasicBlock::iterator MBBI = MBB.begin();
   DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
@@ -71,7 +72,7 @@ void MSP430FrameLowering::emitPrologue(MachineFunction &MF) const {
       .addReg(MSP430::SPW);
 
     // Mark the FramePtr as live-in in every block except the entry.
-    for (MachineFunction::iterator I = llvm::next(MF.begin()), E = MF.end();
+    for (MachineFunction::iterator I = std::next(MF.begin()), E = MF.end();
          I != E; ++I)
       I->addLiveIn(MSP430::FPW);
 
@@ -108,7 +109,7 @@ void MSP430FrameLowering::emitEpilogue(MachineFunction &MF,
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   MSP430MachineFunctionInfo *MSP430FI = MF.getInfo<MSP430MachineFunctionInfo>();
   const MSP430InstrInfo &TII =
-    *static_cast<const MSP430InstrInfo*>(MF.getTarget().getInstrInfo());
+      *static_cast<const MSP430InstrInfo *>(MF.getSubtarget().getInstrInfo());
 
   MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
   unsigned RetOpcode = MBBI->getOpcode();
@@ -138,7 +139,7 @@ void MSP430FrameLowering::emitEpilogue(MachineFunction &MF,
 
   // Skip the callee-saved pop instructions.
   while (MBBI != MBB.begin()) {
-    MachineBasicBlock::iterator PI = prior(MBBI);
+    MachineBasicBlock::iterator PI = std::prev(MBBI);
     unsigned Opc = PI->getOpcode();
     if (Opc != MSP430::POP16r && !PI->isTerminator())
       break;
@@ -188,7 +189,7 @@ MSP430FrameLowering::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
   if (MI != MBB.end()) DL = MI->getDebugLoc();
 
   MachineFunction &MF = *MBB.getParent();
-  const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+  const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
   MSP430MachineFunctionInfo *MFI = MF.getInfo<MSP430MachineFunctionInfo>();
   MFI->setCalleeSavedFrameSize(CSI.size() * 2);
 
@@ -214,10 +215,84 @@ MSP430FrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
   if (MI != MBB.end()) DL = MI->getDebugLoc();
 
   MachineFunction &MF = *MBB.getParent();
-  const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+  const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
 
   for (unsigned i = 0, e = CSI.size(); i != e; ++i)
     BuildMI(MBB, MI, DL, TII.get(MSP430::POP16r), CSI[i].getReg());
 
   return true;
 }
+
+void MSP430FrameLowering::
+eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+                              MachineBasicBlock::iterator I) const {
+  const MSP430InstrInfo &TII =
+      *static_cast<const MSP430InstrInfo *>(MF.getSubtarget().getInstrInfo());
+  unsigned StackAlign = getStackAlignment();
+
+  if (!hasReservedCallFrame(MF)) {
+    // If the stack pointer can be changed after prologue, turn the
+    // adjcallstackup instruction into a 'sub SPW, <amt>' and the
+    // adjcallstackdown instruction into 'add SPW, <amt>'
+    // TODO: consider using push / pop instead of sub + store / add
+    MachineInstr *Old = I;
+    uint64_t Amount = Old->getOperand(0).getImm();
+    if (Amount != 0) {
+      // We need to keep the stack aligned properly.  To do this, we round the
+      // amount of space needed for the outgoing arguments up to the next
+      // alignment boundary.
+      Amount = (Amount+StackAlign-1)/StackAlign*StackAlign;
+
+      MachineInstr *New = nullptr;
+      if (Old->getOpcode() == TII.getCallFrameSetupOpcode()) {
+        New = BuildMI(MF, Old->getDebugLoc(),
+                      TII.get(MSP430::SUB16ri), MSP430::SPW)
+          .addReg(MSP430::SPW).addImm(Amount);
+      } else {
+        assert(Old->getOpcode() == TII.getCallFrameDestroyOpcode());
+        // factor out the amount the callee already popped.
+        uint64_t CalleeAmt = Old->getOperand(1).getImm();
+        Amount -= CalleeAmt;
+        if (Amount)
+          New = BuildMI(MF, Old->getDebugLoc(),
+                        TII.get(MSP430::ADD16ri), MSP430::SPW)
+            .addReg(MSP430::SPW).addImm(Amount);
+      }
+
+      if (New) {
+        // The SRW implicit def is dead.
+        New->getOperand(3).setIsDead();
+
+        // Replace the pseudo instruction with a new instruction...
+        MBB.insert(I, New);
+      }
+    }
+  } else if (I->getOpcode() == TII.getCallFrameDestroyOpcode()) {
+    // If we are performing frame pointer elimination and if the callee pops
+    // something off the stack pointer, add it back.
+    if (uint64_t CalleeAmt = I->getOperand(1).getImm()) {
+      MachineInstr *Old = I;
+      MachineInstr *New =
+        BuildMI(MF, Old->getDebugLoc(), TII.get(MSP430::SUB16ri),
+                MSP430::SPW).addReg(MSP430::SPW).addImm(CalleeAmt);
+      // The SRW implicit def is dead.
+      New->getOperand(3).setIsDead();
+
+      MBB.insert(I, New);
+    }
+  }
+
+  MBB.erase(I);
+}
+
+void
+MSP430FrameLowering::processFunctionBeforeFrameFinalized(MachineFunction &MF,
+                                                         RegScavenger *) const {
+  // Create a frame entry for the FPW register that must be saved.
+  if (hasFP(MF)) {
+    int FrameIdx = MF.getFrameInfo()->CreateFixedObject(2, -4, true);
+    (void)FrameIdx;
+    assert(FrameIdx == MF.getFrameInfo()->getObjectIndexBegin() &&
+           "Slot for FPW register must be last in order to be found!");
+  }
+}