From 700ed80d3da5e98e05ceb90e9bfb66058581a6db Mon Sep 17 00:00:00 2001
From: Eli Bendersky <eliben@google.com>
Date: Thu, 21 Feb 2013 20:05:00 +0000
Subject: Move the eliminateCallFramePseudoInstr method from TargetRegisterInfo
 to TargetFrameLowering, where it belongs. Incidentally, this allows us to
 delete some duplicated (and slightly different!) code in TRI.

There are potentially other layering problems that can be cleaned up
as a result, or in a similar manner.

The refactoring was OK'd by Anton Korobeynikov on llvmdev.

Note: this touches the target interfaces, so out-of-tree targets may
be affected.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175788 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/PowerPC/PPCFrameLowering.cpp | 41 +++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

(limited to 'lib/Target/PowerPC/PPCFrameLowering.cpp')

diff --git a/lib/Target/PowerPC/PPCFrameLowering.cpp b/lib/Target/PowerPC/PPCFrameLowering.cpp
index 9948d61cd0..cc1ed6967b 100644
--- a/lib/Target/PowerPC/PPCFrameLowering.cpp
+++ b/lib/Target/PowerPC/PPCFrameLowering.cpp
@@ -1124,6 +1124,47 @@ restoreCRs(bool isPPC64, bool CR2Spilled, bool CR3Spilled, bool CR4Spilled,
 	       .addReg(MoveReg));
 }
 
+void PPCFrameLowering::
+eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+                              MachineBasicBlock::iterator I) const {
+  const PPCInstrInfo &TII =
+    *static_cast<const PPCInstrInfo*>(MF.getTarget().getInstrInfo());
+  if (MF.getTarget().Options.GuaranteedTailCallOpt &&
+      I->getOpcode() == PPC::ADJCALLSTACKUP) {
+    // Add (actually subtract) back the amount the callee popped on return.
+    if (int CalleeAmt =  I->getOperand(1).getImm()) {
+      bool is64Bit = Subtarget.isPPC64();
+      CalleeAmt *= -1;
+      unsigned StackReg = is64Bit ? PPC::X1 : PPC::R1;
+      unsigned TmpReg = is64Bit ? PPC::X0 : PPC::R0;
+      unsigned ADDIInstr = is64Bit ? PPC::ADDI8 : PPC::ADDI;
+      unsigned ADDInstr = is64Bit ? PPC::ADD8 : PPC::ADD4;
+      unsigned LISInstr = is64Bit ? PPC::LIS8 : PPC::LIS;
+      unsigned ORIInstr = is64Bit ? PPC::ORI8 : PPC::ORI;
+      MachineInstr *MI = I;
+      DebugLoc dl = MI->getDebugLoc();
+
+      if (isInt<16>(CalleeAmt)) {
+        BuildMI(MBB, I, dl, TII.get(ADDIInstr), StackReg)
+          .addReg(StackReg, RegState::Kill)
+          .addImm(CalleeAmt);
+      } else {
+        MachineBasicBlock::iterator MBBI = I;
+        BuildMI(MBB, MBBI, dl, TII.get(LISInstr), TmpReg)
+          .addImm(CalleeAmt >> 16);
+        BuildMI(MBB, MBBI, dl, TII.get(ORIInstr), TmpReg)
+          .addReg(TmpReg, RegState::Kill)
+          .addImm(CalleeAmt & 0xFFFF);
+        BuildMI(MBB, MBBI, dl, TII.get(ADDInstr), StackReg)
+          .addReg(StackReg, RegState::Kill)
+          .addReg(TmpReg);
+      }
+    }
+  }
+  // Simply discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions.
+  MBB.erase(I);
+}
+
 bool 
 PPCFrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
 					MachineBasicBlock::iterator MI,
-- 
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