Move the eliminateCallFramePseudoInstr method from TargetRegisterInfo

[oota-llvm.git] / lib / Target / XCore / XCoreFrameLowering.cpp

diff --git a/lib/Target/XCore/XCoreFrameLowering.cpp b/lib/Target/XCore/XCoreFrameLowering.cpp
index bb9c77a32fe6a0d19eca7d988e23f6c19b60b57e..019c4570d93d9e392b1da759b516b7bdae4c3650 100644 (file)
--- a/lib/Target/XCore/XCoreFrameLowering.cpp
+++ b/lib/Target/XCore/XCoreFrameLowering.cpp
@@ -332,6 +332,58 @@ bool XCoreFrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
   return true;
 }
 
+// This function eliminates ADJCALLSTACKDOWN,
+// ADJCALLSTACKUP pseudo instructions
+void XCoreFrameLowering::
+eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+                              MachineBasicBlock::iterator I) const {
+  const XCoreInstrInfo &TII =
+    *static_cast<const XCoreInstrInfo*>(MF.getTarget().getInstrInfo());
+  if (!hasReservedCallFrame(MF)) {
+    // Turn the adjcallstackdown instruction into 'extsp <amt>' and the
+    // adjcallstackup instruction into 'ldaw sp, sp[<amt>]'
+    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.
+      unsigned Align = getStackAlignment();
+      Amount = (Amount+Align-1)/Align*Align;
+
+      assert(Amount%4 == 0);
+      Amount /= 4;
+
+      bool isU6 = isImmU6(Amount);
+      if (!isU6 && !isImmU16(Amount)) {
+        // FIX could emit multiple instructions in this case.
+#ifndef NDEBUG
+        errs() << "eliminateCallFramePseudoInstr size too big: "
+               << Amount << "\n";
+#endif
+        llvm_unreachable(0);
+      }
+
+      MachineInstr *New;
+      if (Old->getOpcode() == XCore::ADJCALLSTACKDOWN) {
+        int Opcode = isU6 ? XCore::EXTSP_u6 : XCore::EXTSP_lu6;
+        New=BuildMI(MF, Old->getDebugLoc(), TII.get(Opcode))
+          .addImm(Amount);
+      } else {
+        assert(Old->getOpcode() == XCore::ADJCALLSTACKUP);
+        int Opcode = isU6 ? XCore::LDAWSP_ru6_RRegs : XCore::LDAWSP_lru6_RRegs;
+        New=BuildMI(MF, Old->getDebugLoc(), TII.get(Opcode), XCore::SP)
+          .addImm(Amount);
+      }
+
+      // Replace the pseudo instruction with a new instruction...
+      MBB.insert(I, New);
+    }
+  }
+  
+  MBB.erase(I);
+}
+
 void
 XCoreFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
                                                      RegScavenger *RS) const {