1 //===-- XCoreFrameToArgsOffsetElim.cpp ----------------------------*- C++ -*-=//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // Replace Pseudo FRAME_TO_ARGS_OFFSET with the appropriate real offset.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "XCore.h"
15 #include "XCoreInstrInfo.h"
16 #include "XCoreSubtarget.h"
17 #include "llvm/CodeGen/MachineFrameInfo.h"
18 #include "llvm/CodeGen/MachineFunctionPass.h"
19 #include "llvm/CodeGen/MachineInstrBuilder.h"
20 #include "llvm/Support/Compiler.h"
21 #include "llvm/Support/raw_ostream.h"
22 #include "llvm/Target/TargetMachine.h"
23 using namespace llvm;
24 
25 namespace {
26   struct XCoreFTAOElim : public MachineFunctionPass {
27     static char ID;
28     XCoreFTAOElim() : MachineFunctionPass(ID) {}
29 
30     bool runOnMachineFunction(MachineFunction &Fn) override;
31 
32     const char *getPassName() const override {
33       return "XCore FRAME_TO_ARGS_OFFSET Elimination";
34     }
35   };
36   char XCoreFTAOElim::ID = 0;
37 }
38 
39 /// createXCoreFrameToArgsOffsetEliminationPass - returns an instance of the
40 /// Frame to args offset elimination pass
41 FunctionPass *llvm::createXCoreFrameToArgsOffsetEliminationPass() {
42   return new XCoreFTAOElim();
43 }
44 
45 bool XCoreFTAOElim::runOnMachineFunction(MachineFunction &MF) {
46   const XCoreInstrInfo &TII =
47       *static_cast<const XCoreInstrInfo *>(
48           MF.getTarget().getSubtargetImpl()->getInstrInfo());
49   unsigned StackSize = MF.getFrameInfo()->getStackSize();
50   for (MachineFunction::iterator MFI = MF.begin(), E = MF.end(); MFI != E;
51        ++MFI) {
52     MachineBasicBlock &MBB = *MFI;
53     for (MachineBasicBlock::iterator MBBI = MBB.begin(), EE = MBB.end();
54          MBBI != EE; ++MBBI) {
55       if (MBBI->getOpcode() == XCore::FRAME_TO_ARGS_OFFSET) {
56         MachineInstr *OldInst = MBBI;
57         unsigned Reg = OldInst->getOperand(0).getReg();
58         MBBI = TII.loadImmediate(MBB, MBBI, Reg, StackSize);
59         OldInst->eraseFromParent();
60       }
61     }
62   }
63   return true;
64 }
65